Clutch Q

87 MM 2.6/km132 Bought it with a cracked head and the transmission growling. Found a used trans to put in and was going to replace the clutch at the same time. When driving even a very slight amount of clutch pressure caused it to slip. I thought the cable was adjusted properly, I had 1-2" of freeplay at the top

The problem: When I pulled the trans out and pressure plate off, it appears to be pretty close to new. The flywheel still has grind marks on the wear surface and the clutch disc looks pretty good too.

My question: should the flywheel have a step ground into it, or should it be perfectly flat from the outer ring where the pressure plate bolts to the inner ring where the clutch disc sits? Mine is ground flat FYI

Anyone have a new clutch disc and can measure its thickness?

Any input appreciated.

Hi and welcome to mightyram. A member had a similar problem recently and it turned out to be the throw out bearing. Somehow the bearing had about 1/4" difference in travel distance due to it being shorter. They weren't able to identify how that had happened but they ended up welding a small extension onto it to make up the space. Also it could be a bent clutch arm or if the cable has been replaced, the cable is different or you need to take up the slack a bit more. Also check the firewall for movement - these trucks are known to crack metal around the clutch cable adjuster. I personally would try adjusting the cable up first and work my way through the list to eliminate the cause. The flywheel face should be perfectly flat.

The free play should be 3/4" at the top - 1-2" should make it hard to disengage the clutch. I agree with Geezer - check the throwout bearing against the one in the tranny you took out - there are 2 different throwout bearings for the km132, and even one with the bearing with a plastic housing. If they are different, you can swap the bearings between housings.

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Originally Posted by pennyman1

The free play should be 3/4" at the top - 1-2" should make it hard to disengage the clutch. I agree with Geezer - check the throwout bearing against the one in the tranny you took out - there are 2 different throwout bearings for the km132, and even one with the bearing with a plastic housing. If they are different, you can swap the bearings between housings.

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Even with excess free play at the top the clutch engaged the last inch before the free play. Clutch disc has about 1/8" of friction material on each side before it gets to the rivets

Guess I'll buy a new clutch kit and see if anything is different. Don't have any other options

I replaced with a new auto zone clutch, nothing fancy. The new disc was .040" thicker than the old one and the new pressure plate had .030" more engagement than the old one. Put it all together (with new throw out bearing and pilot bearing of course) and its like new. Clutch fully disengages all the way in and starts engaging just off the floor

sounds like you got it set up right.

i ran into the same problem of where the cluitch engages or disengauges theres an adjustment under the dash for clutch pedal throw it should measure 7 inches from the floorboard i got mine right by playing with that and the clutch cable adjustment