Clutch shudder and horseshoe shims
 

I recently replaced my clutch when I could no longer shift without grinding the gears. I assumed my problem was a spring slipping out of place on the clutch disk. What I found was a broken rivet. I got a new disk and reassembled the whole clutch assembly with one difference; I measured the gap between the flywheel housing and the block. The gap was .020” so I added extra shims. Now I have severe shuddering when shifting into 1st and reverse Did I just screw up? Another observation: I adjusted for the normal 1” of free play on the clutch pedal but when I look at the throw out bearing, it starts catching when the free play is only 1/4”
TIA Ian

Re: Clutch shudder and horseshoe shims
 

My guess is you just needed the .010 shims that are standard. Brent and others have posted many times about aligning the flywheel housing and those shims. Others will know more than me.


As for the free play, I'm confused. Where is the 1/4" of free play you're talking about? Also what is catching?

Re: Clutch shudder and horseshoe shims
 

You need to dial in the flywheel housing and then shim as necessary.


Bob

Re: Clutch shudder and horseshoe shims
 

To clarify, when the clutch pedal is pushed down 1/4", the throw out bearing begins to touch at least one of the fingers on the pressure plate. The clutch pedal can easily be pressed down one inch using one finger.

Re: Clutch shudder and horseshoe shims
 

Following Bob C's advice insures the crankshaft and transmission input shaft are on the same plane..the clutch engages and disengages true (provided the release fingers are set right) the transmission shift smoother too.

Re: Clutch shudder and horseshoe shims
 

The clutch fingers all need to be touched at the same time.If the throwout bearing touches one,then another,they are out of whack.Did you set the fingers after the new disc was installed?If the fingers are not even,it will chatter and kick like an old mule.

Re: Clutch shudder and horseshoe shims
 

The flywheel housing, flywheel, and disk must all be in parallel planes. The flywheel housing must be shimmed to be within .006 inch of the crank flange. The flywheel "wobble" must be within .005 inch. A dial indicator is essential to set up the clutch. The clutch release fingers must be within .002 inch of each other. Let us know how it goes.

Re: Clutch shudder and horseshoe shims
 

It's generally a good idea to have both the disk and the pressure plate rebuilt or renewed at the same time. The condition of the flywheel is also important. Clutch housing alignment doesn't have as much to do with the clutch as it does the livelihood of main input shaft & bearings in the transmission but it is very important none the less.

Much of the reproduction clutch stuff is suspect. I send my old originals out for rebuild by shops that take care to get them right.

Re: Clutch shudder and horseshoe shims
 

If you exercise care in rotating the crankshaft you can dial indicate the housing alignment with the engine in the car,its common practice on heavy trucks to dial in the flywheel housing with the engine installed.The reason its important to do is if the shafts are out of alignment the clutch disc will engage in one area of the flywheel first,instead of the total disc engaging,creating a chatter.