The truck in question is an 81...my 4sp died so a 5sp replacement tranny thats going in is from a mid 80s (I cannot be more precise with the year for this one). If it helps with figuring out the problem...I also have a backup 4sp that's outwardly identical to the 5sp. My issue as as follows:
Ok 1 problem: I cannot get the transmission to line up with the pilot bearing. The bell goes on just fine on its own. The input shaft at its narrowest and thickest is identical to the old transmission and pilot tool and it goes into the clutch disc fine...BUT!
The input shaft is 3 1/8th inch instead of 3 1/4 like the old tranny. The closest I can get the transmission installed is 1/8th an inch from flush...I do not have enough input shaft length it seems to make it to the pilot bearing to complete the lining up. NOTE: The input shaft of both the 5sp and spare 4sp are identical...so even if I was using the latter I'd still have the same problem. I've spent 2 afternoons so far trying to get it lined up.
Here's my question: Did flywheel thickness change at all between 81 and 88? It would seem that if it were even 1/16th an inch thinner I could jostle the tranny into place. I already eliminated the throwout bearing hitting the fingers as a culprit...there's a good inch or so of travel as it currently stands before the 2 touch when I move the fork. Or possible is the newer years pilot bearing thicker?
I'm at a loss to get things lined up. It seems as if the tip of the input shaft reaches the pilot bearing but I can't seem to get it started...this is with someone in the cap of the truck maneuvering the rear of the tranny with a rope while I'm underneath manhandling the bell and the rest.