Clutch Diaphragm Spring Rotation Question

With the primary cover off and the engine running, I noticed that the diaphragm center, where the clutch pushrod adjuster screws in, spins with a slight elliptical influence rather than a true circular motion. I compressed the clutch spring and reset the retaining clip to make sure all was seated well which it was, but that slight elliptical spin/motion is still in play. Not exaggerated by any means but noticeable.

Could this indicate something is out of its true seating? I understand there is a small bit of play allowed when the diaphragm spring is in place within the clutch chainwheel... which is turning in a true circular manner. New clutch pack was installed during overhaul and is working nicely.

You have crushed the mainshaft support circlip. Remove . Fettle in the better thicker one into the slot. The MK 111 e-starter one. Tighen down the clutch nut less with blue locktight. No retainer tab.

The torque value is erronious. 40 ft. lbs. is the right number. Or, you will repeat this outcome indefinately.

Could possibly be the spring is binding unevenly on the centre collar. Dismantle and skim a bit of metal of the leaf inner ends. Check the previous posters thoughts first.

My final torque setting was 40. I may have taken it further and not liked the way it felt and backed off to 40...pretty sure that's what I did....either way I now have some specifics to look for.
Is over tightening the usual cause of the circlip getting squashed or should I be looking for something less obvious?
I reassembled with fewer shims as using the same amount I removed with new clutch pack was not setting up properly....or so it appeared.

Any and all observations/commentary are appreciated and my thanks for your attention guys.

Edit:
Do you mean extra plain plate "shims"?

L.A.B. said:

Edit:
Do you mean extra plain plate "shims"?

Click to expand...

I was referring to the spacing shims/washers that slide onto the main shaft after the machined/recessed locating washer has been located over the circlip...thanks.

Lineslinger said:

I was referring to the spacing shims/washers that slide onto the main shaft after the machined/recessed locating washer has been located over the circlip...thanks.

Click to expand...

Ok, so you did mean the primary drive shims behind the clutch assembly as I first thought in which case they should be replaced unless the primary drive alignment has been checked and found not to need them but they shouldn't affect clutch operation as they are outside of the clutch assembly.

Aren't we really talking about the end of the mainshaft wobbling a bit? I'd be surprised if this isn't a common thing.

rvich said:

Aren't we really talking about the end of the mainshaft wobbling a bit? I'd be surprised if this isn't a common thing.

Click to expand...

I could be that as well. But, while I have the cover off its not that big a deal to dismantle and take a look and I get a bit of peace of mind figuring out the cause. I will follow up with what I find and I thank you guys for the input.

What rvich said.

I pulled clutch/gearing/sprockets and found absolutely nothing wrong.
Torque was 40 ft. lbs.
No crushed circlips. Drive sprocket to clutch housing alignment all good, spacers/shims all good as they were when I rebuilt it.

Since I already have the system disassembled and already dropped yet another $10 on ordering two of the "stronger" circlips (renovation of these machines will $10 - $20 dollar you to death! But thats for another thread), I will just wrap the components and wait for the new one's (circlips) to arrive.

I am glad I checked it over though, no real downside other than my shop is around 95+ degrees today and the AC cannot keep up.
Working in that kind of heat sucks.

View media item 187View media item 186

rvich said:

Aren't we really talking about the end of the mainshaft wobbling a bit? I'd be surprised if this isn't a common thing.

Click to expand...

It's not supposed to, but yes I've had that happen. Catastrophic failure of alternator rotor broke the primary chain and bent the gearbox mainshaft. Replaced the broken parts and always thereafter had issues with the clutch. Then one day I ran the motor with primary cover removed and saw the clutch basket wobbling.

I suppose it might be worth setting up a pointer (or a dial indicator) and by rotating the gearbox through some revolutions look at the shaft to verify how far out it is. My comment that it is probably common wasn't meant to imply it was correct. I don't know how far out this can be before it starts to cause issues. If you do a search on here for "bent mainshaft" there will be lots of reading.

Was the elliptical motion noticeable at the outer circumference of the clutch housing?

This conversation will eventually lead to the weight of the clutch hanging on the end of that shaft, which is one of the only things that keeps me awake at night.

Well personally as I previously mentioned I think the spring leafs are binding on the centre, when you pull the clutch does it get worse? I would mark one side of the centre orientated with the tilt, take the Spring out, rotate the centre 90 deg , reinstall and see if the tilt is the same, I.e. 90degs back from the mark. Then do the same relative to the clutch basket.

As you noted in your original post Lineslinger, there is considerable play of the diaphragm spring within the clutch outer (chainwheel). With a little fettling you may be able to center the spring so that the wobble is minimized. It would be best to confirm your trans. mainshaft is true first though, as rvrich posted.
A bit of wobble should only cause a little heating at the clutch pushrod.

When checking the gearbox main shaft with my dial indicator it shows a true/centered rotation, no fluctuation.
So, my next step was to confirm free movement of the diaphragm spring "fingers". Movement is free without hindrance. So the only component left to address, as far as I can tell is the centering of the diaphragm main spring on the shaft.

Is the diaphragm main spring supposed to have a slight bit freedom within the chainwheel? I would think it would have a bit of free float for assembly/disassembly and operation.
As I said the elliptical rotation is barely noticeable, except I noticed it.

When my new circlip's come in I will reassemble the entire primary drive and give consideration to the centering of the clutch spring before releasing the pressure back onto the plates. I'll set up the dial indicator on the main spring hub and see where that takes it but my suspicion is that every time the clutch is put into operation the centering will fluctuate a bit.

I had to dial in the blow proof bell housing on a 427 side oiler for proper alignment to prevent the mainshaft bearing from wearing "out of round" and leaking engine oil into the clutch works. The "out of round" tolerances were minute for that application and I cannot see this requiring the same....or does it? That's where my concern stems from, the trickle down effect of and out of round/balance influence on the end of the shaft.

I am assuming that the installation of the diaphragm plate does not call for "dialing" it in with an indicator. Not in the manual.

Thanks for the input guys, it gives me more to consider while trying to analyze this.

The shaft is true! That's good news. Now keep it that way!

I'd put it together and go for a ride. And yes there is freedom of movement of the diaphragm inside the clutch housing/chain wheel. You will note when you use your compression tool that once the diaphragm is flattened enough for removal that it easily rotates within the housing. I'm not sure of the clearance but easily a few thousandths. I was able to shim my diaghragm .020 closer to the pressure plate to help with stack height. It made a big difference in clutch pull.

Enjoy.

Russ