MG TD TF Cluster Gears $350.00 Exchange (Free Shipping)


In the early days of the last century one of the major considerations in British motor engineering design was to manufacture at MINIMUM COST and this principle was evident in almost everything that they produced.

One area where this was most notable was in the design of the 4 speed gearboxes fitted to almost every British car. In order to avoid the necessity of adding an extra set of gear teeth to the cluster gear (laygear) with the attendant requirements of additional overall length, extra gear cutting etc., etc. they universally selected not to make the 1st gear a “constant mesh” type but opted instead to use a straight cut (spur) gear so that that gear could also be used as part of the reverse gear train. The inevitable result was the dreaded “non-syncro” 1st gear.

rapierI have a Drivers Handbook for a Sunbeam Rapier MkII within which the writers refer to what is actually 1st gear as “emergency low gear”.

“The use of emergency low gear is recommended when starting on a hill or when the car is fully loaded. It is also desirable, during the running in period, to make full use of all four gears, to ensure that all new parts in the gearbox become bedded in as the process of running in proceeds. Thereafter, low gear may be used for moving off on level ground.

My bet is that when an owner showed up with a ruined gearbox during the warranty period the service manager could confidently point out this paragraph to deny coverage.

As a consequence of this economizing measure the vast majority of these early 4 speed gearboxes failed prematurely as a result of drivers “grinding” them into 1st gear while the car was still moving. When this was done the little chips of hardened steel knocked off the 1st and cluster gears eventually made their way into the roller bearings in the gearbox and destroyed the bearings and the shafts that they ran on.

The “sports car” gearboxes seemed to be more vulnerable to this than the more sedately driven family cars, probably as a consequence of the way they were driven, and this resulted in many premature gearbox failures.

While new replacement parts were available repairing this damage was a fairly straightforward gearbox rebuild but, when the supplies of new gears ran out, this became a serious problem as setting up to manufacture new gears, and in particular new cluster gears, was a very expensive process.

Fortunately some years ago a brilliant and unnamed individual came with the idea of just replacing the 1st gear on the cluster gear and we started purchasing these and installing them in customer’s gearboxes in the ‘90’s.

Of course there is always someone around who can produce a less expensive and lower quality part and after a few years we started to encounter problems with the new gears on the rebuilt cluster gears wearing prematurely.

Testing revealed that the replacement gears that had been failing prematurely were substantially softer than the other gears on the cluster or the original 1st gears so, after some research, we have developed a process that produces a re-manufactured cluster gear of superior quality using modern materials and a high speed welding process that avoids overheating the gear next to the weld.


Re-manufactured MG TD/TF Cluster Gear Available From Stock

I can now offer a limited number of these re-manufactured MG TD, TD MkII, TF and TF 1500 for  gears for sale:

Outright $US395.00

With a rebuildable core $US350.00 exchange.

Prices include shipping to  the US lower 48 or Canada.

Contact info above…..


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BN1 Gearbox Front Seal Replacement

BN1 gearboxes are somewhat renowned for their ability to leave pools of oil on the ground.  One of the most annoying of these leaks occurs when the car is parked facing downhill. This particular leak is inherent in the design.

bn1-gearboxThe BN1  Gearbox and Overdrive Unit

Rather than having a lip type seal this gearbox has a “scroll” seal between the input shaft and the housing. Scroll seals are actually a clearance seal in that there is a small gap between the shaft and the housing and, to prevent the oil from working its way through this gap, one surface, in this case that of the housing, has a thread cut into it which serves to “wind” the oil back into the gearbox.

Scroll seals actually work reasonably well in most situations but when the oil level in the case is higher than the seal and the shaft is not turning they don’t work at all!!!

The normal oil level in the BN1 gearbox is about 1 ½” below the bottom of the front shaft so as long as the car is parked on a relatively level surface all is well however, when the car is parked facing downhill, the oil level at the front of the box can rise sufficiently to submerge the area where the front shaft enters the box with the result that oil can easily leak through the scroll seal and either run down the input shaft and soak the clutch plate linings or just run out the bottom of the bellhousing.

When this gearbox was used in the vehicles for which it was originally designed it did not have an overdrive unit on the back of it. Adding the overdrive unit increased oil capacity and aggravated the “downhill facing” leakage issues.

I was asked to see if there was any way that I could correct this problem on the 100 that I’m presently restoring and after making some measurements determined that it was possible to modify the front seal housing of the gearbox to incorporate a lip seal.

The front housing is a die cast cover which integrates the scroll seal and locks the input front bearing in position.

The first job was to increase the inside diameter of the housing in the area where the scroll seal was originally located by 7/16”. To achieve this I had to figure out a way to center the hole in the face plate of my lathe. After experimenting with a dial gauge for way too long I decided to take a different approach.


Custom Machined Centering Arbor

I turned up an arbor that used the female #1 Morse taper of the headstock spindle as the center and extended forward at the inside diameter of the scroll seal.

centering-castingUsing Arbor to Position Housing

With the housing centered using the arbor it was possible to mark out the centers for 3 holes in the faceplate which were then drilled and tapped with ¼” UNF threads which in turn accommodated hex head screws that were used to secure the housing to the faceplate.

mounted-on-faceplate3 Hex Head Screws Used to Secure Housing to the Faceplate

Once the housing was accurately located on center this way I simply removed the faceplate, extracted the arbor then reinstalled the faceplate with the housing now accurately positioned for machining.

finished-to-size-and-faced-offThe Housing Accurately Machined to Size

The housing was carefully machined to the correct size for the seal and lightly faced off.seal-installedThe Selected Seal was Carefully Inserted

The selected seal was then pressed into place using Locktite to ensure that it stayed in position.

 installed-sealThe Modified Housing Reinstalled

Once the housing was reinstalled into the bellhousing the result looked just great.

I realize that this modification is probably beyond the abilities of the average home restoration so if anyone needs it done I would be happy to modify their gearbox’s front housing and install a seal using the setup I have built, just contact me.

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Tire Truing (A Home Solution)

  • After the concours inspections at Enclave 2015 in Gettysburg, PA I managed to catch the last few minutes of a tech session presented by Ken Beck of K & T Vintage Sports Cars of Allentown, PA  on the dreaded “Scuttle Shake” so common to Austin Healeys.
    The solution proposed in this presentation was to shave the tread of mounted tires to eliminate radial run out. It turns out that this procedure is very effective on our older wire wheels because they are inclined to be somewhat out of round.
    I have encountered scuttle shake many times in Healeys and had found that it was very pronounced on my 100 particularly when running the original “flat center” 48 spoke wire wheels. These wheels are correct for the very earliest of 100s but were replaced by a stronger version early in production.
    Service J

The change to stronger wheels is detailed in the above Service Journal.

When I checked the run out of my wheels I found that they were as much as 0.100″ out of round ….no wonder I had scuttle shake.

Having been unable to find anyone offering the service locally I looked into the idea of shipping my wheels and tires off to PA or NC to have them shaved and trued but the cost of doing that from Canada was more than the wheels were worth!!!

I got to thinking about how might I develop a home remedy for this problem and thought that I could probably achieve the same result with the equipment I have and a little “Kiwi Ingenuity”.


Here’s what I did  …   fortunately we don’t get a lot of OSHA inspections around here.

I have a newly sharpened 60 tooth carbide ripping blade in the saw and you will notice a short length of 2″ x 2″ lumber behind the tire that is forming a rigid strut between the saw bench and the rear axle housing. To avoid damaging the blade I had to be sure to dig all the little stones out of the tread before starting.

Four cuts were required to shave the entire surface of each tire and during each cut the blade was gradually raised, using the blade height adjustment of the table saw, until it was apparent that the blade was contacting the tire throughout its full rotation. The blade was positioned ahead of the wheel center with the wheel is rotating in reverse to prevent the possibility of the blade “digging in”. This particular car has a limited slip differential so both wheels rotate in the same direction when they are in the air. Without a limited slip diff it would probably be necessary to lock the brake on the other rear wheel.

After the cutting was finished the surface of the tire tread was a little fuzzy but that loose rubber wore off entirely within a few miles of driving.

The end result was a total transformation. At 60 MPH, the speed where it was previously most pronounced, the car has no scuttle shake at all and that is on a set of wheels that have never been balanced!!!









Posted in Healey Stuff, The Restoration of Healey #174, Used Parts | Leave a comment

Lucas 17L Tar-Top Battery Solution

During the final weeks of the restoration of my early Austin Healey 100 it became apparent that acquisition of original style batteries was going to become a major problem.

The only “acceptable” batteries for a concours car are original “Lucas” 6 volt 17L “tar-top” batteries.

BN1 Batteries

BN1/2 Battery Installation

I had acquired a pair of originals with a view to having them rebuilt but, when I made inquiries about having this done, it quickly became obvious that this was just not going to happen as the only re-builders that I could find worked exclusively on large industrial batteries and had neither the parts nor any interest in tackling such a small job.

I had had a pair of reproductions on order for some months but calls to the supplier were not encouraging and the chances of getting them before Enclave 2015 were virtually nil!

I decided that an alternate plan was called for.

Ballistic in Mini

Ballistic in Mini Race Car

I had seen several track racing minis equipped with Ballistic Lithium Ferrous Phosphate batteries and, having had some experience with starting highly tuned competition engines, I felt sure that if one of these batteries could start a race mini it could probably start a Healey 100 engine with a compression ratio of only 7.5:1. When one of the mini racers mentioned that his Ballistic battery had provided good service for 3 seasons I was convinced.

The problem is of course that this modern battery really did not look much like the old “tar-top” Lucas relic from 1953!!

Ballistic EVO2 16 Cell

Ballistic EVO2 16 Cell

However, upon further investigation, it became apparent that the tiny size of these modern batteries meant that one with sufficient cranking capacity for a Healey would easily fit inside the case of the original Lucas battery.

Here is how it is done.

Of course to start you have to have a pair of original or reproduction tar-top batteries to modify.

First remove the fill caps and drain all the old electrolyte out of the original batteries. Be sure to use rubber gloves and wear goggles while working with the battery. Also see if you can safely recycle the acid and not run it down the drain. Do rinse the case over and over before you start cutting and pulling stuff out. You may also want to wear a mask as acid fumes are nasty. (Thanks Ira).

The next task is a bit brutal.

Battery Top Cut Off

Battery Top Cut Off

Using a large band saw or similar implement of destruction cut the tops off the original batteries. Cut straight across all the way just below the bottom of the hold down lugs then pull out all the lead plates and dispose of them safely.

Removal of Lead Plates

Removal of Lead Plates

The next task is to remove the 2 dividing partitions from the case of one of your 2 batteries. These need to be cut out right down until they are level with the grid in the bottom of the case. A multi-purpose oscillating tool works quite well for this but I’m sure there are plenty of other methods.

Partitions Removed

Partitions Removed

Note: With the second battery it is only necessary to cut some small “V”s out of the top of the partitions but we didn’t figure that out until all the work had been done to remove them entirely.

Battery Lid Guide

Battery Lid Guide

To ensure that the lid will index accurately when replaced on the case we installed some plastic guides on the underside of the lid.

Once this is done you will find that your new Ballistic EVO2 16 Cell battery will easily fit right inside the case.

Ballistic Battery in Lucas Case

Ballistic Battery in Lucas Case

I used some strips of Styrofoam insulation to “nest” the Ballistic battery and ensure that it wouldn’t rattle around inside the case.

The next task is to connect the Ballistic battery to the +ve and –ve posts molded into the lid of your original battery. These connections and the cables will have to carry the full load of the starter so they have to be fairly substantial.

Jumper Cables Connecting Ballistic Battery to Original Posts

Jumper Cables Connecting Ballistic Battery to Original Posts

I used sections of some old heavy duty booster cables to make up short jumpers for this. It was necessary to drill and tap the undersides of the posts to secure the terminals that I had soldered onto the ends of my jumpers. Be sure to make the jumpers long enough that you can attach the Ballistic battery terminals to them as you install the lid.

Drill and Tap The Undersides of Both Posts on Both Battery Lids

Drill and Tap The Undersides of Both Posts on Both Battery Lids

With the second battery it is only necessary to make up a jumper, again heavy duty, to link the +ve and -ve terminals. That is why some small “V”s in the partitions on the second battery are all that is required.

Jumper Connecting Posts Inside 2nd Battery

Jumper Connecting Posts Inside 2nd Battery Lid

It is not necessary to glue the top back in position as the as the original battery securing rods will hold it in place..


The Modified Battery is Indistinguishable from the Original

Now install the batteries into the car and you are almost finished.

Once Installed the now Acid Free Batteries Look Totally Authentic

Once Installed the now “Acid Free” Batteries Look Totally Authentic

One last thing and this is very important if you want your expensive lithium ferrous phosphate batteries to last a long long time.

The instructions that come with the Ballistic battery emphasize that over charging will permanently damage the battery so it is essential that you adjust the regulated output of your generator to ensure that the maximum voltage that it can produce is 13.6 volts.

I found this very simple to achieve and procedure is clearly explained in section O/13 of the Factory Workshop Manual. It is the regulator adjustment that needs to be adjusted as this is normally set to something around 15.5 volts for a lead/acid battery.

Use a digital voltmeter to get it right and make sure that you drive the car while checking the revised output voltage just to ensure that it is correct.

I would recommend leaving a note inside the cover of the regulator indicating that it will require readjustment if lead acid batteries are installed in the car at some later time because an output setting of 13.6 volts will decrease the storage capacity of such batteries.

A couple of other things that are important to remember are:

  1. Just like a lead acid battery your Ballistic battery will be permanently damaged if allowed to completely discharge so be sure to turn off your master switch when you are storing the car for more than a few days.
  2. A regular battery charger is capable of delivering more than 13.6 volts… Be sure to use one that will not overcharge your Ballistic battery
Posted in Healey Stuff, The Restoration of Healey #174 | 4 Comments

Smiths and Jaegar Fuel Gauge Solution

This gallery contains 2 photos.

After having all the original Smith’s instruments in my latest Austin Healey restoration entirely rebuilt I was rather disappointed to discover that the fuel gauge reading was so erratic that it was difficult to know just how much fuel I … Continue reading

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Low Mileage Austin Healey 100. A Rare Opportunity to Look Back.

Recently Bob Yule of Autofarm Ltd was kind enough to allow me to take a close look at a very early 1954 Austin Healey 100, with only 5300 miles on it from new, that he had in his shop for service.

One does not often get the chance to examine such an original car close up so I am very grateful to Bob, Tom and the owner of the car for this opportunity.

Having just completed the restoration of my own BN1 I had a number of details that I was very keen to check and during the course of the inspection I photographed several interesting and little known details about these early cars.

The car in question is C. BN1L 151405 body number 1267 and the engine number is 1B205529.

Car LH front

The car’s original paint is a very unusual “Gunmetal Grey” colour. Records have been found for around 6 cars painted this colour at around the same time so it is thought that this was a “trial balloon” to see if it was a seller.

The interior is bright red (persimmon), which is also original.

Although the car is in outstanding condition for a 60 year old vehicle a couple of small “additions” have been made to the electrical system and unfortunately the engine and gearbox have at some stage been out and reputedly rebuilt. Whoever did the engine rebuild did a good job but some details of the re-installation have been done a little carelessly meaning that those areas affected by this work are somewhat suspect insofar as originality is concerned.

The following are some very interesting details that I noted on the car which were previously unknown to me although I’m sure some at least are well known to others.

 Generator terminal phenolic separator plate.

Plate on generator terminalsI suspect that the paint was applied after the engine rebuild. I believe that this was an original, but often discarded part, as it can be seen in the in Fig.8 on page O/7 of the factory workshop manual.

Small tag on wiring harness.

Wiring harness tag

Handbrake lever finish.

Handbrake plating and tunnel paint. Handbrake polish

Shift knob lock nut.

Shift knob lock nut

The vent duct material.

Good shot of the original fresh air ductingMost restorers use “Kopex” tubing in this location but that is definitely not what was used originally. I think it may also have been used in early Sprites. If anyone can tell me where to get some of this I would be very grateful.

Horn rim securing screws.

Horn screwsI had always thought that these screws were painted with the horn but on these horns they most definitely were not. What is strange is that overspray of the horn paint is often seen on the black spring disc under the sounding disc..

Low tension connection at distributor.

Distributor low tension leadOf note here is the unpainted engine number plate. I suspect that this is one of the things done incorrectly during the engine rebuild. It is pretty well confirmed that these were painted engine colour.

I should also mention that the rubber sleeve was used on most connectors on these early cars other than grounding points.

Knotch in bottom on RH inner sill. (this one really surprised me)

Fender and inner sill knotchI believe that this knotch was necessary on right hand drive cars because the outer support bracket for the pedal shaft is only 3″ from the inner sill meaning that the inner sill would prevent the shaft from being removed. On the left side there is 5″ between the bracket and the inner sill although the exhaust down pipe would have to be removed in order to remove the left hand drive shaft. As the bodies were the same for left and right hand drive cars it would have been necessary to cut this knotch in all bodies to prevent problems on the line. There was no sign of this knotch on body #174 so I really have no idea about which cars had this…most confusing.

The bonnet latch parts appear to have been plated.

Bonnet catch striker pin and cap finish

Bonnet latch sliding plate finishI have pointed these finishes out because there are errors on this point in the 2015 Concours Guidelines

Fuel line in trunk painted black.

Fuel line in trunk

Seat runner reinforcement plates under floor.

Seat runner reinforcement plates

Tonneau cover and windshield spring parking posts on scuttle.

Scuttle posts left Scuttle posts rightI believe that the windshield springs are meant to be “parked” on the inner post. There was no reason to believe that these posts had ever been changed so I have no idea why they are different side to side. On later cars a “Lift The Dot” post was used for the springs but on earlier cars all 4 were Tenax posts.

Bumper splash pan securing screws.

Splash pan outer screwsBy installing these 10/32 screws with the nut forward only the head was visible inside the fender which looked tidier. This is common to all 100s other than on very early BN1’s where  self tapping screws were used here again with the head visible inside the fender.

 Harness clip secures cables at gearbox cover adaptor plate.Cable clip at tunnel adaptor plateAgain common to all 100s and sometimes hand painted black.

Poor panel alignment.

Door alignmentThe panel alignment is really quite poorly done with the crease line on the drivers door being almost 1/4″ above that of the fender.

Boot lid seal is installed in the shroud gutter not on the lid.

Lower right corner Lower right side Right side Top left side Top right side Upper left cornerThis is something that I have been pretty sure of for some time so it is nice to have it confirmed. With the aluminium boot lid it would have been very difficult to install the seal on the lid because of various obstructions. The seal itself appears to be very similar in section to that used on the steel lids but it has a strange “mesh” surface texture.

The parts book refers to this seal being 4 pieces but on this car it was definitely a single piece of foam rubber.

There are several other interesting details on this car that were new to me so more later.


Posted in Healey Stuff, The Restoration of Healey #174 | 2 Comments

BN1 Gearbox. A Plethora of Threads

Back in the days when I was a really poor British sports car mechanic I managed to pick up a Suzuki LJ80V all-wheel drive van with a badly slipping clutch to use for winter transportation.

Suzuki LJ80V

Suzuki LJ80V

It was a horrible little thing but great in the snow and all I could afford at the time. Before I could use it I had to replace that clutch and in doing that job my opinion of Japanese design improved immeasurably. The only tool required to change the clutch, which required that a gearbox with a 4WD transfer case be removed, was one 13 millimeter wrench. ONE!!!



For a guy who was accustomed to using almost every tool in his 15 drawer tool cabinet and a few borrowed ones just to change a fan belt in an MGB this was a revelation and made me realize just how far the British motor industry had to go in 1953 when they started producing the Austin Healey 100.

From the manufacturers perspective such simplicity can produce extensive benefits because not only is the vehicle easier to construct and service but the parts inventory required both for construction and after sales service is dramatically reduced.


The Austin Healey 100

The Austin Healey 100

1952/3 must have been interesting and challenging times for the Austin engineers as the Longbridge factory was geared up to produce the new Austin Healey 100. Britain was desperate for overseas sales but their factories were old and funds for new machinery and imported materials were just not available.

Unfortunately as a result of the shortages the new car had to use an old power train. The engine, with two cylinders lopped off, was a copy of a pre-war six cylinder Bedford lorry power unit which had been adapted from a 1929 Chevrolet design. There was no time or money to “modernize” the engineering so it was still being produced with outdated British Standard threads, British Standard Fine (B.S.F) and British Standard Whitworth (B.S.W) at a time when all new designs were being produced using the modern SAE thread system of Unified National Fine (U.N.F) and Unified National Course (U.N.C.). This was not ideal situation but there really weren’t any viable alternatives.

However, if the engine was not exactly “start of the art”, the gearbox was even less suitable for the latest in sporty motoring vehicles. Adapted from a column change saloon car “cog box” it was never designed to handle even the modest 144 lbs. ft. of torque delivered by the lump ahead of it but, again, it was all that was available within the budget so it had to be used. I suspect another factor was that Len Lord the president of the newly formed British Motor Corporation had hundreds of them lying around as a result of the Austin Atlantic disaster.

The BN1 Gearbox

The BN1 Gearbox and Overdrive Unit

Studying the threads used in this gearbox gives us an idea of the lengths the engineers at Austin needed to go to in their efforts to get those Healeys out the door.

The starting point was a 4 speed box designed to be used in vehicles like the Austin 16, a staid family car with barely enough power to “pull the skin off a rice pudding” as my Dad used to put it. The first job was to come up with an inexpensive way to produce a floor shift as no self-respecting “sports car” could have anything resembling the “three on the tree” gear change that the gearbox was designed around. This was achieved with a nifty adaptation of the original gearbox side cover and the addition of an Austin Taxi “change speed control box body” upon which a gear lever could be pivoted.

The Change Speed Control Box Body

The Change Speed Control Box Body

Everything worked out just fine but the threads… oh my, the threads.

Change Speed Box Cover Stud

The interesting thing about this “change speed control box body” is that within the design of this small cast part 3 different threads were used and that is just the beginning!

Two Different Threads in Very Close Proximity

Two Different Threads in Very Close Proximity

It was found that because of the 4.125/1 Austin Healey differential ratio (another saloon car legacy) 1st gear in the four speed box was useless and reputedly produced “nothing but wheel spin with anything like a spirited take off.” (See note below). The solution was that the 1st gear in the box would need to be blanked off producing a three speed gearbox.

One can only imagine the wails of anguish from the marketing department as no sports car of the day could be sold with a three speed gearbox even if it was all synchromesh … an overdrive unit was required. Fortunately the Laycock-de Normanville unit selected was a modern design which used U.N.F. and U.N.C. threads.

Speedometer Pinion Bearing Locking Screw

Speedometer Pinion Bearing Locking Screw

This clever addition appeased the marketing department but really complicated the thread issue as it required an adaptor plate with BS threads on one side and SAE threads on the other; not a design achievement that any engineer could be very proud of.

Joseph Lucas’s Switch

As a further complication the overdrive unit required a plunger switch on the side of the gearbox to prevent the overdrive being engaged when the gearbox was in reverse as doing so would destroy the overdrive unit. Enter Joseph Lucas. Now Joe was a very traditional guy and, apparently, a big fan of BS threads which the Lucas Company stuck with right through into the 1970’s so the switch he supplied used yet another thread form namely British Association (B.A.).



So now we have five different threads in this unit; B.S.F., B.S.W., U.N.F., U.N.C., and B.A….but wait… there’s more! We have to consider the drain plug for the gearbox.

The Tapered B.S.P. Threaded Drain Plug

The Tapered B.S.P. Threaded Drain Plug

Rather than use a standard parallel thread screw with a soft washer under its head the gearbox incorporated yet another thread system British Standard Pipe (B.S.P), which is tapered, in order to stop the oil from leaking out and to save the cost of a sealing washer.

Surely at this stage the engineers must have been tearing their hair out; six different thread standards in one gearbox unit but we aren’t finished yet.


As a grand finale the box incorporated this 1 7/16” LEFT HAND THREADED nut with fourteen threads per inch to lock the front bearing of the gearbox onto its shaft. As far as I can figure there is no “standard” for this gem.

The Front Bearing Nut

The Front Bearing Nut

Seven different thread forms in one gearbox unit that’s quite an achievement. You can see why I was so impressed by the Suzuki.


I have a theory about why the 4.125/1 rear axle ratio was used in the 100.

Geoffrey Healey states in “The Healey Story” that ”Austin did not have a high* enough gear ratio for the A90 rear axle” but that is not strictly correct. The Austin Atlantic convertible used a much better 3.66/1 ratio which, incidentally, was even offered as an option on the 100 and a 2.92/1 and even a 2.69/1 ratio became available in the 100S and those cars used the same rear axle housing .

Conventional wisdom has it that the 1st gear in the BN1 gearbox was too low and produced excessive wheel spin but I think that is a marketing myth. Donald Healey in “My World of Cars” states “The only disappointing part of the A90 was its gearbox, which was not man enough for the job in a sports car”.

My bet is that it was discovered early on that the torque of the engine was just too much for the gearbox and “The New Austin Healey 100 with enough torque to rip the teeth right off its 1st gear” didn’t sound like a winning slogan. The decision was made to stick with the lower diff ratio, which meant that 2nd gear starts were satisfactory, and “block off” 1st gear in the interests of reliability. Unfortunately that limited the top speed to 90MPH at maximum RPM, a problem solved by fitting an overdrive unit.

* A “high ratio” differential has a low ratio number whereas a “low ratio” has a high rati0 number.

Posted in Healey Stuff, The Restoration of Healey #174, Used Parts | 1 Comment

Laycock-de Normanville Overdrive Installation Tool

Many years ago I made up a little tool which has proved invaluable when attaching an “A” type Laycock-De Normanville overdrive unit to a gearbox.

For those not familiar with this operation a little explanation will help. If you have “been there, done that” skip this part down to the picture with the tape measure in it.

The rear shaft of the gearbox mated to these overdrive units has to be aligned with three individual splines while compressing an oil pump spring and 8 clutch springs as the two units are joined together.

One of the splines is located on the inside of the oil pump cam.

Oil Pump Cam With internal Spline

Oil Pump Cam With internal Spline

The other 2 sets of splines are away down in the middle of the overdrive unit, one in the clutch sliding member and the other in the unidirectional clutch.

8 Springs, 3 Splines, Big Problem

8 Springs, 3 Splines, Big Problem

As can be seen in the above picture when the pump cam is positioned on the pump plunger roller the plunger spring holds the cam out of alignment with the rest of the bore of the unit.

Conversely when the cam is fitted on the partially installed gearbox shaft the pump plunger roller protrudes below the cam and will not allow the cam to slip by into its correct position against the overdrive centre bushing.

The Pump Roller Blocks the Pump Cam

The Pump Roller Blocks the Pump Cam

The factory workshop manual for the Austin Healey 100 illustrates the “recommended” method of installing the overdrive. They suggest “placing the oil pump cam in position on top of the center bushing (as in the photo above) then carefully threading the mainshaft through the oil pump cam and into the center bushing.”

Try Holding a Gearbox at Arms Length Like This for a Few Minutes

Try Holding a Gearbox at Arms Length Like This for a Few Minutes

What they don’t mention is that the gearbox weighs in at some 25 kg so holding it with one hand as illustrated while attempting to align the various components with the other is just a little difficult.

They also add as a NOTE: ”the gearbox mainshaft should enter the overdrive easily provided that the lining up procedure previously described is carried out and the unit is not disturbed.”

Well, if I know of one sure way to become “disturbed”, it is to try to mate the gearbox to the overdrive the way that they describe!

This is where the little tool mentioned above can help you maintain your sanity.

The Tape Measure is For Scale. (In Case You Didn't Guess)

The Tape Measure is For Scale. (In Case You Didn’t Guess)

This very inexpensive “Special Tool” is made from a piece of coat hanger wire. After you find out how well it works you may want to get it chrome of even gold plated!

So…How does it work?

In the filter cavity of the overdrive unit there is a conveniently located hole.

Tool in Place Viewed From Below

Tool in Place Viewed From Below

The “Special Tool” is inserted through this hole and up the side of the pump plunger.

Tool in Place Before Installing Springs

When the pump plunger is pushed down against its spring the hooked end of the “Special Tool” engages into the plunger just below the roller and holds the plunger in the down position. It is easiest to install the “Special Tool” before placing the clutch springs in position.

The shape of the little hook on the top of the “Special Tool” is very important but not difficult to form.

Again..Pencil Tip is for Scale

Again..Pencil Tip is for Scale

Now when the cam is placed in its correct position there is plenty of clearance between the lower section of the cam and the plunger roller allowing the cam, while installed on the gearbox shaft, to pass into position against the overdrive centre bushing without contacting the pump roller.

No More Interference Problems

No More Interference Problems

Now the installation procedure is much easier.

Use a little heavy grease to hold the pump cam in place on the gearbox shaft with the high part of the cam uppermost.

Position the overdrive unit with the drive shaft flange on the ground.

If You Can't Find Anyone to old the Overdrive Bolting The Flange to a Piece of Wood Works.

If You Can’t Find Anyone to old the Overdrive Bolting The Flange to a Piece of Wood Works.

Use a dummy shaft to check the alignment of the internal splines and then ensure that all the clutch springs are correctly installed (short ones innermost).

Put the gearbox into 1st gear then carefully lower the gearbox down onto the overdrive unit. You may have to turn the gearbox input shaft to align the splines inside the overdrive. When the gap is down to about 1/2″ peer in using a flashlight to ensure that the clutch springs are all correctly positioned at the top.

The gearbox and overdrive should pull together easily.

Don’t forget to extract and save your “Special Tool”.

Posted in Healey Stuff, Restoration Techniques, The Restoration of Healey #174 | 3 Comments

LUCAS HF1748 Horn Rims

At last after months of back and forth with various die makers and die casters I have received a shipment of horn rims for the Lucas HF1748 horns.

These 12 volt horns were used on Austin Healey 100-4 (BN1 and BN2), 100M, 100-6 (BN4, BN6), and 3000 Mark I (BT7, BN7), Jaguar XK 140, XK150, Mark VII VIII & IX, Mark II, and Aston Martin DB3/S vehicles. The same design of horn was also available in 6 and 24 volt versions.

This whole process was initiated by my being unable to find a pair of the original, zinc die cast, rims for the horns on my 1953 Austin Healey 100.



Because the horns are mounted low down under the radiator they are very vulnerable to damage and corrosion. The first and often only part to break is the rim which is secured by six steel ¼” B.S.F. cheese head screws. Galvanic corrosion of the rim produces zinc oxide which swells and causes the rim to crack. The ones on #174 each came off in completely unusable condition.



As the last of these horns were fitted to cars over 50 years ago spare parts are very hard to find. After trolling the internet for over 2 years I was only able to find one already cracked rim so I started investigating methods by which the rim could be reproduced

The work required to produce these accurate reproductions has given me a new respect for anyone who undertakes small batch production of any cast component, that said however I still don’t have much time for companies who make “close approximations” when, with a little more effort and time, they could produce parts which are indistinguishable from the originals.

The first idea that I investigated was 3D printing. Because I don’t have access to a 3D scanner the first step in that process was to produce a CAD drawing of the rim. Fortunately I have a very good friend with vast CAD drawing experience who was kind enough to work on this for me. Everything went swimmingly until the time came to find the correct font for the “LUCAS” lettering as was on the original rims.

I had no idea that there were so many fonts in the world and we were unable to find one which had the straight side on the “U” and an “S” that looks like a mirror image “Z” as the lettering was on the original. The only solution was to painstakingly draw each letter and individually position them on the curve of the rim, a very time consuming process.



Finally the drawings were done and sent off for 3D printing in nylon.

Although the plastic rims produced by 3D printing were pretty good they required quite a bit of post-production work which included filling the surface indentations with spot putty followed by careful sanding and painting to produce a reasonably acceptable part. The biggest problem however was the cost of the 3D printing process which is, after all, intended for making prototype parts.

I was not satisfied that this process would ever be practical for making even a small batch of accurate rims at a reasonable price so started looking for a more viable alternative.

Given the difficulty that I had encountered in finding replacement rims I decided that it may be possible to have a set of steel cavity molds made and produce the parts using the “Cold Chamber Die Casting” method.

Die casting of high volume parts is very economical but the initial outlay to produce the die is substantial. I figured that if I could sell 100 rims that could cover the cost of the die and the manufacturing of the rims. The die maker was very helpful and by modifying a die used previously and fitting my work in between other jobs he managed to produce a very accurate die within my budget and the casting process started.



The quality of the finished parts was absolutely astounding and the rims can be installed without any hand finishing at all.

I decided to send one to Roger Moment, the world renowned Austin Healey expert, and his comments were as follows:

“I have been able to inspect one and it is truly accurate.  The only variation I can find is that on the back side of the ring there are 5 marks where the vents and fill sprue on the mold were located.  These marks are all flush or slightly recessed so they won’t affect the mounting and are totally hidden.  …The cast metal surface is totally smooth, as-original.”





My efforts and investment were all worth it but it is a very complicated and expensive way to get a pair of horn rims. I certainly won’t be casting any more in the foreseeable future.

If you require accurate replacement rims for your Lucas horns please don’t hesitate to contact me.

Posted in Healey Stuff, New Parts, The Restoration of Healey #174 | 4 Comments

Early Austin Healey 100 Steering Wheel Detail.

When I was a little nipper back in Dunedin, New Zealand our family car, the first I remember anyway, was a 1948 Austin 16.

An Austin 16 BF1 Our Family Car 1954 -63

An Austin 16 BF1 Our Family Car 1954 -63

I have 4 siblings so journeys in the Austin with 3 in the front and 4 in the back were cozy affairs.

The Austin's Dashboard

The Austin’s Dashboard

There was always a race for which of the kids got to ride up front between Mum and Dad, whom of course always drove. As a result I spent many hours at pretty close quarters with the dash and controls of that Austin and many of the details are etched indelibly in my memory. I remember the combined ignition and lighting switch with the little window within which the words “OFF”, “SIDE” and “HEAD” showed and I remember the cream coloured instruments with the brown centers.

The Lucas Combined Headlight and Ignition Switch

The Lucas Combined Headlight and Ignition Switch

I recall the turn signal switch in the center of the steering wheel, with its chrome handle and the brown Bakelite steering wheel center.

Among my recollections, for some reason is the finish on the hub of the “banjo” style steering wheel. It was “wrinkle” paint with the same texture as my Dad’s Philco radio which was “wrinkle” brown. It is amazing the details that one remembers so clearly from one’s childhood.

The memory of the hub of that steering wheel immediately sprang to mind when I studied the original steering wheel for the 1953 Austin Healey body #174 that I have just finished restoring but first a little background.

The first 1000 Austin Healeys did not have the luxury of seat slides. If you needed to adjust the distance between the seat and the pedals a half inch wrench was used to unbolt the seat and move it to another of the 5 pairs of holes provided in the seat base.

The "High Tech" Seat Adjustment System on #174's Driver's Seat

The “High Tech” Seat Adjustment System on #174’s Driver’s Seat

Not really convenient but I presume that the tooling required to produce compact seat slides had not been produced at that time, so compromises were required.

Additionally those first 1000 cars had a steering wheel which, after loosening a locking nut, could be moved forward or backward on the steering column. This feature was dropped for the later 100s when seat slides were eventually fitted but reintroduced, as an option, on the six cylinder cars.

The adjustable wheel on the early 100s used a hub with locking nut which had the manufacturer’s name “BLUEMEL’S” stamped on it. Interestingly the profile of the early hub was considerably different from that used on the 6 cylinder adjustable steering wheels.

Early 100 Steering Wheel Hub Profile. (Mike Lempert Photo)

Early 100 Steering Wheel Hub Profile.
(Mike Lempert Photo)

But the really interesting thing is the finish on this early hub which was, I believe, black wrinkle paint just like the wheel on my Dad’s Austin 16.

The Steering Wheel  Hub Profile of a  6 Cylinder Austin Healey

The Steering Wheel Hub Profile of a 6 Cylinder Austin Healey

As can be seen in the picture below the finishing material on the early 100 hub is is only microns thick and crumbles into dust when peeled off. It is like normal paint in this respect.

Detail of The Finishing Material Used on The early 100 Steering Wheel Hub  (Mike Lempert Photo)

Detail of The Finishing Material Used on The early 100 Steering Wheel Hub
(Mike Lempert Photo)

The material used on the later six cylinder adjustable steering wheels is not paint, is very similar to powder coat being about 0.025” thick and it can only be peeled off in larger pieces.

The Thicker Finishing Material Used on the Later 6 Cyl Adjustable Wheel Hub

The Thicker Finishing Material Used on the Later 6 Cyl Adjustable Wheel Hub

The other interesting difference between these finishes is what happens to them when they are polished. The later hub coating easily polishes up to a deep gloss black surface.

The Later Hub Finish After a Little Polishing

The Later Hub Finish After a Little Polishing

The material on the early wheel appears to be pock marked and rough with pitting on the surface and will not polish to a glossy surface.

Detail of The Original Finish on #174's Wheel

Detail of The Original Finish on #174’s Wheel

Unfortunately most of these early 100s have be restored over the last 60 years and it is very difficult to confirm for sure that they had this unique “wrinkle” finish on the steering wheel hub but there is no question that the material used to finish the hub was very different from that used on the later cars and it was also different from plain gloss black paint.

I have decided therefore that, in light of a lack of evidence to the contrary, it is most likely that in addition to being used on the heater housing and air filters black wrinkle paint was the finish applied to these steering wheel hubs and that is what I have used in the restoration of #174.

The Refinished Wrinkle Black Steering Wheel Hub on #174

The Refinished Wrinkle Black Steering Wheel Hub on #174

I think it looks great and very much “period correct”.

Posted in Healey Stuff, The Restoration of Healey #174, Used Parts | Leave a comment