Ok, I just swapped tailshafts and replaced the clutches in my C6. Should I be able to turn the shaft after everything is put together? I was thinking if might be because I have new clutches? This is my first rebuild so I ain't got a clue. Everything seemed to line back up fine, I had a rough time getting the clutches to line up. I'm sure there's got to be an easier way. The front went right back in and sit down like it should but I just can't turn it like I can the old one, did I screw something up? Oh, BTW, it ain't in park either

 

Yes, everything should turn easily. There has got to be free play in the stack after you put the pump on. With the pump tight, pry everything up and down with a screwdriver. There should be between 1/32 and 1/16 free play - see the rebuild manual for the exact amount. Usually excessive tightness is caused by one of the clutch plates or steels not being engaged in the next drum properly. You have to pre-align them with a pick or small screwdriver,then you still need to wiggle going down. The top drum has a particular feel when it is right, it wiggles less when it is settled properly. You can adjust the stack play by buying a collection of different thickness top shims at, for example, NAPA, but usually when the stack is assembled properly a used transmission will have too much free play, not too little.
Another common problem causing inadequate free play, is that one of the thrust washers or shims has come off the stack and is cocked against something, often the ears are now bent. Replacement thrust washers will also be in the NAPA washer and shim kit. The thrust washers and spacers should be stuck to the part the ears nest into with vasoline-petroleum jelly. Do not use any other type of grease, it won't dissolve like petroleum jelly. The stuff from the baby section of the supermarket. This will keep them from coming off and going crooked or getting bent.

 

You're talking about shaft movement in and out, right? I think I got all of the clutches engaged, it felt like it. I was wondering about spinning the shaft like the engine would, should I be able to like I can on the old one?

 

Did you try it after you put the snap ring on ?

 

it seemed all fine until I bolted the front on. I'm going to tear it back down and do it again.

 

No, I'm not talking about the tailshaft when refering to stack free play. With the valve body out, and the pump screwed down, pry with a screwdriver on the toothed edge of a drum towards the back. Then pry it forwards. Measure the amount it moved. I don't use an instrument, I can see that it is 1/32" to 1/16" visually. If you don't have some stack play, the transmission won't rotate, and it is not assembled properly. Either a washer has fallen off crooked (use petroleum jelly to stick them on, no other kind of grease) or a clutch isn't fully engaged. Getting the clutch engagement right is tricky, I had to put the pump on 3 times last month before I got it right. I balance the transmission on its tailshaft between my knees while I sit on a log, that is the only way I can get the clutches to engage right. See the ATSG transmission rebuild book, JC Whitney PN ZW167280, warning: order by mail without phone number or Email address, otherwise they will drive you crazy with 3 ads a day. 761 Progress parkway, lasalle, Il 61301. Good Luck.