Recently helped my son buy a 96 K1500 4.3 4wd 5-speed. Clutch disengagement was very high on the pedal, leading me to believe it would need a clutch soon. We got the parts and he's put several hundred miles on it without much of an issue, but thought he felt it starting to slip so we went in.

Now, I've done 20+ transmission replacement/swaps, so I'm not exactly new to this. But I've never specifically done a K1500 5-speed (I'm aware that the 4.3 and 5.7 are virtually identical from the rear). So far, the hardest part during the removal phase was that lovely slave cylinder quick-connect, but plenty of cleaner spray and patience I got it out intact. The first thing I noticed upon removal was that there was NO pilot bearing installed in the flywheel at all. The second thing was that the clutch friction plate and pressure plate looked relatively good - clearly a lot of life left in the friction plate. We decided to put all the new parts in for now and keep the used but still good pieces. I'm still struggling to come up with a reason why it was engaging/disengaging so high on the pedal - any thoughts there?

Anyway, on the actual issue. We've stabbed this thing in 3 times already, in the same relative manner I've done numerous auto transmissions, with NO luck, I get to approximately 3/8 to 1/2" from flush and it binds up (pilot bearing insert realm). I know better than to force the gap closed - but I've tried all the tricks in my bag and it keeps binding. Is there something special to the manual trans? Do you just have to force it? Any tips or tricks appreciated! I am a little worried that the lack of a pilot bearing has made the input shaft out of round and it simply won't mate up now.

TLDR: Engine/transmission won't mate all the way (1/2" out it binds). Found NO pilot bearing installed. Tips/tricks to get them to flush up??

Jon

 

In my experience that would mean the clutch plate wasn't aligned correctly. Will an alignment tool slide in and out easily? Before you installed the pilot bearing, I'm assuming you did install one, did you check the fit on the transmission input shaft?

 

It has what I would term the typical slight hitch as it enters the pilot bearing, but goes in and out easily enough bolted up as is. I did test fit the pilot bearing on the shaft with the trans out of the truck. I did install one. I actually was thinking the same thing (have had friction plates move inside pressure plate during install and require re-alignment), but the alignment tool slipped right back in after I pulled the transmission back out the first time.

 

I'm thinking then that it is that slight hitch that is getting you, maybe go back loosen and realign the plate and try for a no hitch.

 

I have had the slight hitch numerous times in the past without this issue, but I'll give that a shot.

 

Many years ago I switched to a metal alignment tool as the plastic ones that come with the kit often proved problematic,

 

Well I've realigned it 3 more times (twice no hitch at all but tight feeling, once hitch but cheated the way I expect it to deflect), and done 5 or so more stabs out of it with EXACTLY the same results. I've never had anywhere NEAR this much trouble getting a transmission in. I had my 95 Trans Am down to in and out in 45 minutes. This is absurd.

On closer input shaft inspection, it has a visible amount of play (probably from being run without a damn pilot bearing). I tried cheating up as I expect the shaft to take a little weight as it gets finagled into place. Might try down, but at this point I'm just poking and praying. Can't believe I'm the only one who's had this much trouble.

The truck probably isn't worth a new transmission. Would probably find a totaled V8 truck and swap it.

 

That input shaft slop is probably your issue, it would be hard to tell where the end of the shaft would end up using the clutch disk as a pivot point. Hope you are able to get it installed, and wish you luck finding a used one, manual transmissions were on their way out by then and have become slim pickings at least in my area.

 

You might try to drive the bushing further in with a soft drift pin, could be it isn't back far enough.

 

I installed it to flush with the surface (bearing vs. bushing), it had to be driven in to even get there. I might try to get it in a little further and it might help - but I still just don't think it's aligning.