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TR4/4A 4 - 4A Clutch Adjustment Difference

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T

TR Tom

Senior Member
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Well, I’m totally confused!
During a total engine, clutch and transmission rehab, I decided to convert to a 4A / 6 style diaphragm clutch on my 65 4. While doing research, I found that the later cars use a self adjusting clutch. This is something I’ve never dealt with before, or understood.

It appears that the only difference between the two systems is the absence of the external return spring (Moss #329-485 or #84 in the picture). Am I reading that right, and there are no other differences (except the clutch components themselves)? Does this mean the release bearing is always riding the clutch fingers on the new style? If so, this goes against everything I have ever understood about proper clutch function. Am I missing something here?

My other question is if I even need to use the self adjusting function. Or can I just screw out the pushrod until the piston bottoms out in the slave cylinder, then back it off 0.1” like I’ve always done with my 3’s and 4’s (as I said, never owned a 4A), and of course use the external return spring?
 
I would NOT do this unless the new flywheel is balanced, with the crank, as an assembly.
You can not just throw on a different one and pull an Alfred E Newman.
Setting the free play at the slave is just a 2 minute service, don't over think it.
Mad dog
 
Machine shop balanced entire engine as part of rebuild, including new clutch plate. They are also the ones that redrilled my existing flywheel for the 4A pattern. They are very familiar with the TR engines and have done this before, so I’m confident this part is done correctly. I also swapped out for the later style short transmission nose piece and correct release bearing.

My questions have to do with the hydraulics:

Did Triumph really just eliminate the external return spring in order to convert from manual to self adjusting? With all other parts remaining the same?

Does this mean the release bearing is always in contact and spinning? If so, why is this not a bad thing?

And do I need to use the self adjusting feature, or can I just leave the spring on and continue to manually adjust the clearance as I always have? As Mad Dog says, it’s an easy job. I’ve been doing it for over 50 years, so don’t mind, as I’m kind of in the habit anyway.
 
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