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TR2/3/3A OD Transmission vs 5 speeed conversion

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I have added the HVDA conversion to three cars. The first one was a TR3B which was already running a TR4A flywheel and clutch. The next two were TR4'swhich have the same flywheel as the late TR3/3A. On the last two I had a machine shop drill and tap the new holes and locating pins. Because I was building a whole car, the flywheel and engine were balanced together.
as Randall stated if you have the earlier bull nosed starter you will need a different starter. Because you will be using the Toyota bell housing there is NO cross shaft to run the Triumph throw out bearing. So you need to use the throw out bearing supplied by Herman.
Hope this helps your decision.
 
I put the HVDA Toyota conversion in my TR3A. I used a TR4A flywheel I bought off e-bay for $50 plus about $20 for shipping.
 
TR3driver said:
But true. Ask Herman. His reply to me was "Well, you don't have to adjust it very often."
Click to expand...

Mine hasn't needed adjustment yet - after several years in service.

I swapped the 3A flywheel for a 4A flywheel, used a new TR4A/6 clutch cover/pressure plate and a later starter. Other than that it's a bolt on change.
 
A lot of good input, which has raised couple of additional questions:


  • How can I tell if I have a an early or later model starter
  • My car (TR3A) currently has a 4 speed, fully syncro, TR transmission (I dont know if its from a TR4, or later model triumph). Does this mandate that I already have a TR4 or later flywheel, or could it still have the original TR3 flywheel. If the former it will make life a lot easier if I go to the conversion.

Thanks,

Richard
 
Early one looks like this:
12803.jpg

Late one looks like this:
9038.jpg
 
Another clue is the size of the bulge on the RH side of the bell housing. Early starters fit in a small bulge:

mg58NS9xR9vpJv_tSQx1NSA.jpg


Whereas the later starters required a longer bulge:

url


Also -- as I recall early starters went with a press-on flywheel and later ones a bolt on flywheel (can be viewed if the lower flywheel shield is removed).

Alas, none of this (starter noses, bulges & flywheels) is easy to see and some mix & match may have occurred.
 
Scotsman said:
How can I tell if I have a an early or later model starter
Click to expand...
Look for the narrowed section next to where the starter mounts to the engine, as shown in Randy's first photo above. The exposed portion of the early starter is also much longer than the later one, closer to 12" than 9".
  • My car (TR3A) currently has a 4 speed, fully syncro, TR transmission (I dont know if its from a TR4, or later model triumph). Does this mandate that I already have a TR4 or later flywheel, or could it still have the original TR3 flywheel. If the former it will make life a lot easier if I go to the conversion.
Click to expand...
The starter must match the flywheel; but the later gearbox will work with either starter and any of the 3 flywheels. So you could still have an early TR3A flywheel with the later transmission, but only if you also still have the early starter. If you have the later starter, then you could have either a later TR3A through TR4 flywheel (which takes the early clutch but the later starter); or a TR4A flywheel (which takes the later clutch and the later starter).

People do sometimes mistakenly try to fit the early starter with the later flywheel. The combination will go together and sometimes even work for awhile. But the starter teeth don't engage properly with the flywheel teeth and it usually doesn't work for long.
 
OK Geo, do you have a big bulge in your starter, or a small one...in the picture above. Another way to put it, is the picture of an early or later bell housing.
 
The top pic is the small bulge. The lower pic doesn't seem to have posted right for me, but I assume it would be the large bulge:



If you have the TR4 synchro box, then you have the large bulge.
 
Right. The bulge in the bellhousing is needed to clear the starter drive on the later starters. However, the early starter works just fine with the bulge present, it just doesn't need the extra space. I drove for about a decade that way; then switched to a gear-drive starter (which also doesn't required the bulge but works just fine with it there).

Here's another view of a 4-synchro gearbox with the bulge. You can see where the bulge was rubbing on my early transmission tunnel (guess I didn't enlarge that area quite enough the first time).

 
Randall, do you know what the final drive ratio is when in OD for the gears it works in? How does it compare to the W58?
 
DanB said:
Randall, do you know what the final drive ratio is when in OD for the gears it works in?
Click to expand...
Varies somewhat, depending on exactly which gearbox & OD you have. Here's the ones I've got handy, but I think they were changed again (slightly) for later TR6 and maybe for TR4.
TR2-3:
OD 2nd 1.65
OD 3rd 1.09
OD 4th 0.82

TR6 early (A-type)
OD 2nd 1.72
OD 3rd 1.14
OD 4th 0.82

TR6 later (J-type)
OD 3rd 1.11
OD 4th 0.797

Those are gearbox ratios of course; if you want overall ratio, you'll need to multiply by whatever rear axle ratio you have fitted. It is not true (as some have said) that all cars with factory OD also came with 4.10 final drive instead of 3.70. Rather, the connection is that they only listed the 4.10 axle as being available in combination with the OD. (Although I have it on good authority that they would build whatever you wanted, as a special special order) :smile: And there has been plenty of mixing and matching over the years. For example, when my previous TR3A came to me, the original 4.10 axle had been replaced with a 3.70 (tho the OD was still present). The current TR3 came to me with a 4.10 axle and no OD.

PS, IIRC there are more W58 ratios in the world than listed in Herman's tables, plus another Toyota box that is nearly identical but has slightly different ratios as well.
Caveat Emptor
 
More like 1.0/0.82 = 1.22, I think. In other words, the output turns 22% faster than the input.

Yet another example where they did things just a little bit different than the rest of the world.
 
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