TR2/3/3A Clutch and Gearbox Sleeve Differences.

[karls59tr]

The TR3/TR4 front sleeve cover is 3.75". The TR4A/TR6 front cover sleeve is 2.97". Does the difference in front sleeve length have affect the working of the clutch if I am using a TR6 box with a TR3 clutch kit?

 

[TR3driver]

If you use the later diaphragm clutch, you must use the shorter front cover, or shorten the one you have. But the shorter front cover seems to work fine with the earlier clutch.

 

[karls59tr]

Thanks for the info Randall. In regard to the release bearing I'm having trouble visualizing how far the bearing should be pushed on to the carrier. The knowledgeable TR guy here is away for the long weekend and the pictures on Google don't seem to show the correct depth.
The reason it concerns me is I've pulled the gearbox because of a grinding noise, not when the clutch pedal is down but when the pedal is up. The 3 fingers on the pressure plate show a lot of wear....the chrome surface is worn off the fingers where they contact the the release bearing and the new bearing face itself is overly worn for the amount of time it was in there. Now the fact that I had the clutch slave mounted on the wrong side of the bracket(since remedied) may have caused this but I would also like to make sure that the bearing is in the right" position" on the carrier.
How much of the brass carrier should be showing between the fork "groove" and the bearing OR when the bearing is installed correctly is the carrier recessed a certain amount from the "face"? I wish I could post a picture of the set up I removed.

 

[TR3driver]

On a TR3, that bearing is not supposed to even touch the pressure plate when the clutch pedal is released. The return spring on the slave pulls it back (obviously when the pushrod is properly adjusted). Sounds like your return spring was not doing it's job.

There is a large shoulder on the carrier (or at least should be), and the bearing gets pushed solidly against that shoulder. IOW, as far as it will go.

However, that wouldn't affect your problem since, if the bearing wasn't all the way against the shoulder, you would adjust for that when you adjust the slave cylinder.

 

[karls59tr]

Is your picture of the TR6 carrier? Does the TR3 carrier have that" shoulder"???...... because the one I removed from car appears not to have a shoulder that would stop the bearing at a certain point! Would you happen to have a picture of a TR3 carrier to see if it has the shoulder?

I think you mentioned you are using a TR6 box and a TR6 clutch on your 3, correct? I went with a TR6 box and a TR3 clutch so I assume I should go with a TR3 carrier. It's confusing.

 

[TR3driver]

Yes, that is a picture of a TR6 carrier. I don't have a photo of a TR3 carrier handy; but it does have the same shoulder, albeit not as thick as on the TR6 carrier. Or, another way to look at it, the shoulder is also one side of the groove for the fork pins. The dimension I put on the photo (which BTW is from the Buckeye Triumphs site) is for the TR3 carrier.

You should use the TOB & carrier that match your clutch. I am now running a TR6 clutch, TOB & carrier with my TR6 gearbox (actually it's a hybrid, only the housing is from a TR6); but I used the TR3 clutch, TOB & carrier when I originally installed it. The TR6 clutch came later, when I installed the alloy flywheel (which is not drilled for the TR3 clutch).

 

[karls59tr]

OK. I think I have a handle on the situation. Were the round faced bearings ever used for the 3 finger clutch or strictly for the diaphragm 4A/6 clutch? Comparing the 4A/6 round face bearing to the flat faced "2065-16 FM-Mex" bearing that was on my TR3 the round faced unit is a lot higher.
I have a "Green" (Moss?) release bearing that was not used that much that I was thinking of installing on the carrier but there seems to be opinions on other forums that they are not very good and don't stand up.

How was the driveability of your TR3 with the alloy flywheel? Any downside to the conversion?

 

[TR3driver]

Well, John Macartney once wrote of finding a car on the showroom floor with wire wheels on one side, disc wheels on the other, and one of each in the boot. So I can't say with certainty that no one ever mixed up clutch parts. But the TR6 clutch is quite a bit different, which is why both the carrier and the bearing are taller. So I doubt they ever did it on purpose.

I've had the alloy flywheel on two engines now. The TR3A seemed to lack torque way down low, so I had to be careful to rev it up a bit while launching the car (getting started moving) otherwise the engine would die. But the current TR3 motor does much better. Still needs a bit of throttle to launch though, if you just let the clutch out it will die (where the old iron flywheel would lurch and chug and keep going). I've killed it maybe twice in 6 years of daily driving.

The racers talk about how hard it is to keep the alloy flywheel mounted to the crankshaft. I've got pictures showing extra bolts and extra dowels. But I've not seen any indication that is a problem with the setup I have; perhaps because the Fidanza flywheel is machined to actually be a light press fit on the end of the crankshaft, or perhaps because I almost never rev beyond 5k (while they spend a lot of time higher than that). I used the mounting bolts to pull it into place (working back and forth, a fraction of a turn at a time) and had to heat it up to get it off the TR3A motor. I also removed the bolts after it was in place, and added a few drops of high strength Loctite to retain them (then reinstalled and torqued to spec).

The other downside is that aluminum theoretically has a limited lifetime and will weaken with repeated flexing. I probably should be running a scatter shield with it. If I ever do go TR racing, I'll definitely add a shield.

But I really like the effect, it makes the car seem much more nimble in 1st & 2nd gear. Not much difference at higher speeds though. I guess you could call it a disadvantage, since the car is so responsive to the throttle it can be hard to keep it smooth when going over speed bumps and such.

 

[CJD]

Karl,
It goes all the way up!

 

[karls59tr]

Thanks for the pic. I see that the release bearing has the round face but the one i have has the flat face....I guess it dosn't make any difference as the clutch slave adjustment would compensate for any difference in height between the two.

 

[CJD]

The pic is a TR4 bearing, but I will be replacing the bearing with a TR3 style. I'll let you know if the new is rounded or not.

 

[CJD]

And...here are the 2 bearings side by side. I see no functional difference, so I assume my TR4 throwout bearing is from an early TR4...

 

[TR3driver]

And just for contrast, here is the "round face" bearing used on TR4A-TR6. The one labeled "RHP" is the original.