advice on engine pull and clutch change?

[TonyM]

Quick story: So I'm on the ferry the other day and go to start up my truck upon docking. Push in the clutch, turn the key, and the truck hops forward almost hits the car in front of me and stalls (thanks to the EBRAKE)... all this with my foot on the clutch, SO I try again - this time it works., but the clutch feels weird stiffer than usual and not very smooth. I drive to town, stop for coffee, get back in the truck. This time, truck is in neutral, push in clutch anyhow, start it up.... and I try to get it into reverse...ugly grinding... try engaging clutch again... more grinding. ANYHOW, the clutch had been feeling weird when I pressed my foot down it wasn't smooth like before, and the truck had been juddering a bit when taking up drive.... SO somebody told me that my pressure plate probably had bent prongs (or whatever they are called).

So I bought a new clutch kit, and in my experience with my 68GMC 4speed, it is easier to pull the engine and replace the clutch, than to pull the tranny... something with to do with the 4 speed and a crossmember.. ANYHOW I don't have any problem pulling the engine, but would like some advice about the clutch fork and throwout bearing. Does it already come packed with grease? Should it fit tightly into the fork? I have had throwout bearing noise ever since I installed my last clutch and I really don't want to get this all put back together and have that same noise every time the clutch is disengaged. I might be missing a spring on the clutch linkage? I might not have greased it well enough the last time? HELP PLEASE! THanks in advace,
TOny

[boilrman]

Are you sure the clutch linkage doesnt need adjustment? The clutch fork is just pressed onto a ball stud that is screwed into place. My bearing came pre lubed and it would spin freely when installed. There is a nub on the new ones unlike the old one that was perfectly round when I replaced mine. The nub is just to keep it from spinning completly, maybe this is what you are hearing?

To know if your linkage needs adjusted, get a ruler or tape measure and then get to the clutch pedal. With your tape measure the distance the pedal moves down before you start to feel pressure, it should be about 1" of travel. If it is over that, the linkage needs adjustment. This can be done by finding the rod that looks like a piece of "all thread" and has a "T" fitting on it. Move the "T" fitting to adjust it out so that the pedal travel is at or about 1" of travel.

[TonyM]

Thanks Boilrman, the first thing that I checked was the linkage. It was fine...there is freeplay, but definately something is screwed up within the clutch assembly. I am pulling the engine tomorrow evening, should be interesting what I find.

[chevyman 68 C/10]

Sounds like your presure plate is tired. Be sure to check your pilot bushing in the back of your crank for play.

If you detect any slop a roller bearing can be purchased at your chevy dealer, just ask for one from a diesel

good luck

[TonyM]

Thanks Chevyman, excuse my ignorance, but how do I check the pilot bushing in the crank for slop? The original pilot bushing does not have rollers bearings right? Thanks,
Tony

[jlmtrout]

Could be that you broke the center hub on the disk. This happened to me. Took off at a stop light, loud bang, couldn't change gears or take out of neutral. Throw out bearing just clips to fork and should have plenty of pivot so it can slide back and forth on the input shaft collar. Good luck and keep on truckin'!-------Jerry

[chevyman 68 C/10]

To check the pilot bushing use a high gear shaft from an old trans. ,or a plastic line up shaft that can be purchased at your parts store.(you will need one or the other for a line up shaft any way) Place the shaft in the bushing, there should be a snug fit.
And no the bushing on these trucks are not roller,just brass alloy

[Longhorn Man]

chevyman 68 C/10, you can get roller ones, and they are 100X better.

[CoryM]

Id personally just pull the tranny, but I do stuff like that on a hoist so maybe thats why. Anyway, whil eyou got it all apart take a REALLY CLOSE LOOK for cracks on your clutch fork. A unnoticed crack can really ruin your day. Sounds to me like you either ripped the center out of the clutch or threw your release bearing out of the clutch fork.
Good Luck.
CoryM

[chevyman 68 C/10]

Right on, on the roller ones Longhorn Mail. I had told TonyM about them in one of the other posts in this thread----MUCH BETTER than a stock one!!!!

[CE20934]

I'm not a fan of those roller bearing-equipped pilot bearings. The last one I had blew its bearings all over the inside of the pressure plate & chewed up my input shaft. And yes, it was properly lubricated when it was put in.

The brass bushings are a lot easier on input shafts. Plus they don't explode.

[chevyman 68 C/10]

I have been may miles in a 69 chevy one ton wrecker towing every day all day long,never had any trouble from any of my trucks. It was enough to sell me on them. Maybe you got a bad one?

[TonyM]

Thanks guys for all the advice and input. Jerry and Cory, you were right on the money with your guess. The center of the clutch disk had broken free of the rest of the plate. I also noticed when I got everything out that I was missing two bolts out of four, which were supposed to be holding the bellhousing to the tranny.. so it was about 1/4 of an inch out at the bottom. I got it all back together, now it shifts perfectly... but I still have that FREAKIN noise whenever the truck is in neutral with the clutch out. Goes silent when I push the clutch in. I just replaced the clutch bearing so I figure it might be a tranny bearing? Oh well, I'll live with it for now! LATER, and thanks again!
TOny