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· Über Moderator
6,676 Posts
Discussion Starter · #1 ·
I have a couple of questions about installing the clutch and flywheel on a 1.9 CIH:

1) When installing the flywheel-to-crank bolts, one of the six has a longer "shaft" (unthreaded section, same size otherwise). I don't see any instructions relating to this in the factory manual, but I recall a thread that said the longer stud has to be in the "correct" position to ensure the flywheel is exactly centered. There is one hole in the flywheel/crank that is slightly offset. Is this the hole the longer-shafted bolt goes into?

2) Is it REALLY necessary to use new flywheel bolts, as the manual suggests? The original bolts look good, and I have been careful to re-torque them to the recommended 43 ft-lbs, after cleaning the threads and using 242 LocTite. This is a low performance engine, and I doubt it will see much abuse, at least by me.

3) The manual recommends torquing the pressure plate-to-flywheel bolts to 36 ft-lbs. When I tried this, two of the four original 8 mm bolts started to stretch beyond yield. I noticed that the threads in the flywheel are somewhat counter-sunk, and the bolts (assuming that they are the original; they DO have the proper spring washers) are only grade 8.8 (in metric, which I think is only grade 5 in SAE). So I installed new, slightly longer grade 8.8 bolts with the spring washers, and three bolts tightened up nicely at 36 ft-lbs. But the fourth bolt started to stretch at about 30 ft-lbs. I replaced it again, and only went to 34 ft-lbs, and it seems OK. So, my question is, should these have been a higher grade bolt (metric equivalent to grade 8, whatever that is)? Or is the 36 ft-lbs of torque too high? It seems pretty high for only 8 mm bolts.

Any other hints about replacing the clutch and flywheel? I already replaced the rear engine seal, and I greased up the pilot bearing (the manual says to check for roughness, which it wasn't, and lubricate with bearing grease). My release bearing has only 40k miles on it, and was smooth, so I haven't planned to replace that. This thread might prove to be useful to those about to perform a clutch replacement.


· Über Moderator
6,676 Posts
Discussion Starter · #2 ·
Answering my own questions...

And I DO talk to myself!

I was surprised I didn't get a bunch of answers to my questions, especially from such knowledgable people as RallyBob. I am going to attribute it to the website development work that Gary scheduled at the exact moment that I posted this.

But I did get at least a partial answer from the classicopels Yahoo! site, regarding the assembly torque of the pressure plate. Clearly, I need to remove the bolts, replace them since they might be partially yielded, and re-torque them. To, say, 20 ft-lbs? Comments??? Suggestions???

From: [email protected]
Date: Mon Oct 7, 2002 9:34 am
Subject: Re. Clutch and Flywheel Questions and Hints

In all installation instructions that OGTS sends out Gil mentions that the manual is wrong. Can't remember the correct torque off-hand, but it was at best half of 36 ft-lbs, maybe even 15 ft-lbs. You were lucky not to break off the bolt.

As for the other questions, now that the site is back up and running, any comments about the different sized flywheel bolts, or about the need to replace them?

Thanks for your advice.

· Member 1000 Post Club
1,521 Posts
Clutch to flywheel bolts

A) I consulted my 74 manual tonight and it gives 36 ft-lbs as the torque. Its what I've always used. Never had any problems...

B) Flywheel to crank bolts... All 6 of my bolts have the same shoulder length. Also, each is the same diameter (*/- .03mm)... nothing closer in tolerance than another. I also thought there was a passage about one bolt being special... but I couldn't find it. One of the bolts was stamped with some lettering on the head, where as the others were not, but this bolts unthreaded portion was .03mm smaller than some of the others...

If you figure out the the puzzle, let us know.

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