i heard penzoil syncromesh or somethin like that, works well

 

Sounds like a bad pilot bearing to me

 

i know it seems strange but it seems like the shortthrow has cleared up the problem, and just out of curiousity how vcould i check to see if the pilot bearing was going out?

 

first, if its a stock 91 trans then it will be cable not hydrolic. I kind of had the same prob but my clutch had a dual diaphram. I tried different approches and it ended being that the clutch went bad. Too many launches i guess. Like some of the others said, try the obvious and then get real serious. good luck

 

oh yea, my pilot bearing made a lot of noise when clutch was let out but stopped when depressed. A Honda tech of mine said that the pilot bearings are notorious for going bad. If a short throw solved the prob then cool, but keep it on the back of your mind.

 

It will exhibit the symptome you described. If you can't explain away the problem any other way, you have to pull the trans and inspect it. You should always install a new pilot bearing when changing the clutch.... kinda like doing a water pump with a timing belt.

That's usually an input shaft bearing on the trans. It stops making noise when you release the clutch because the input shaft stops spinning in the bad bearing. A bad pilot bearing causes the input shaft to keep spinning even though you release the clutch. Symptoms of a bad pilot bearing are hard/impossible to get into first gear at rest and grinding when shifting into other gears while moving.

 

it's not going to make a diff. as long as you do it at the right time(rpm) and don't grind your gears. lol I take it you never drove a diesal truck before (big rig)
the only time they use a clutch is when there at a stop. I work on diesal's all day long, some have over a million miles on them with the same, tranny. this is not the cause of a bad tranny, nore will it ever be.

 

yes, but you are comparing 2 totally different transmissions. one is more of an industrial build, and the other comercial build. im sure semi-trucks were designed to be beaten up, after all they dive long distances periodically.