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-   -   Drive shaft too long after rebuild (https://67-72chevytrucks.com/vboard/showthread.php?t=767493)

Berlinvet 07-14-2018 08:18 PM

Drive shaft too long after rebuild
 
Ok, perhaps you guys can straighten this out for me. I pulled the TH400 out of my 68 C10 Long Bed, changed the TC and put the tranny back in. So far so good. Now I cant get the darn driveshaft to fit. It's too long. The crossmember mates with the mount on the tranny and the original bolt holes, so I believe the tranny is in exactly the same position it was before - when I removed the drive shaft without any problems. It is all the way in the transmission, cant get it in any further. What the heck is this black magic?

bill3rail 07-14-2018 08:38 PM

Re: Drive too long after rebuild
 
Not sure about the 400's but some auto trannys have different tail shafts.
Did someone rebuild the tranny and put a different tail shaft on it?

Bill

Berlinvet 07-14-2018 08:41 PM

Re: Drive too long after rebuild
 
I can't tell. But that's not whats bothering me. I took the whole thing apart and now I cant put it back together. All same parts apart from TC and flex plate. What gives?

bill3rail 07-14-2018 09:24 PM

Re: Drive too long after rebuild
 
Quote:

Originally Posted by Berlinvet (Post 8301280)
I can't tell. But that's not whats bothering me. I took the whole thing apart and now I cant put it back together. All same parts apart from TC and flex plate. What gives?

When did you pull it?

When did you reinstall it?

Did someone rebuild it?

How far off is it?

Berlinvet 07-14-2018 10:09 PM

Re: Drive too long after rebuild
 
Pulled transmission 2 weeks ago, got new torque converter and flywheel, put everything back together today. No rebuild. Bell housing snug on engine, crossmember holes line up with frame and transmission mount. It appears the shaft won't slide any further into the transmission. It isn't binding, but ALL of the, excuse my laymen term, "shiny part" that goes on the splines is in there to the hilt.

Berlinvet 07-14-2018 10:10 PM

Re: Drive too long after rebuild
 
I'm missing a solid half inch in the rear and that would leave zero wiggle room for any forward or backward movement.

dmjlambert 07-14-2018 10:23 PM

Re: Drive too long after rebuild
 
Is that a 2-piece drive shaft with a skip yoke in the middle?

weq92f 07-14-2018 10:29 PM

Re: Drive too long after rebuild
 
Something is not right here... If the tranny is bolted snug to the block and the new TC didn't crunch in there somehow causing the shaft to not go deep enough, then the shaft should fit back where it came out!

Two piece shaft?

-klb

rjs53 07-14-2018 10:42 PM

Re: Drive too long after rebuild
 
Did your torque convertor go all the way in? Your bell housing wouldn't fit flush with motor if it didn't Unless you really torque it down, in which you broke the pump. Check and see if the motor and trans are all the way together.

Steeveedee 07-14-2018 11:24 PM

Re: Drive too long after rebuild
 
Uh-oh, maybe you stacked the TC. If it isn't bolted to the flex plate yet, does it spin free?

oldgold70c10 07-15-2018 09:56 AM

Re: Drive too long after rebuild
 
Are you having trouble getting the drive shaft shifted foward enough to get the rear u-joint back where it goes? On my truck, the dive shaft will come off with no trouble, but to put back on, I have to jack the rear end up high enough that the shocks are fully extended. Only then will the rear u-joint go back in place.

Berlinvet 07-15-2018 10:11 AM

Re: Drive too long after rebuild
 
Thanks for all the replies. TC did spin before I bolted it to the flex plate. Bell housing mates to engine, no gap. They came together without me having to really torque down the bolts.

It is a 2 piece shaft with the skip yoke.

@Oldgold: yes, that is exactly my problem. REmoved the darn thing without a hitch. Ill try your technique of jacking up the rear.

Steeveedee 07-15-2018 10:34 AM

Re: Drive too long after rebuild
 
Quote:

Originally Posted by oldgold70c10 (Post 8301536)
Are you having trouble getting the drive shaft shifted foward enough to get the rear u-joint back where it goes? On my truck, the dive shaft will come off with no trouble, but to put back on, I have to jack the rear end up high enough that the shocks are fully extended. Only then will the rear u-joint go back in place.

It it is done that way, the bolts attaching the center support to the frame must not be tightened until after the axle is raised back up to ride height, or the difference can push the bearing out of the support.

Berlinvet 07-17-2018 11:54 AM

Re: Drive too long after rebuild
 
Problem found but not solved. Yet. PO seemed to have forgotten to bolt engine down onto motor mounts. Engine shifted back about 2 inches when I pulled the transmission. Now I just need to pull her forward, somehow, and drive shaft should for again. Any pointers as to how that can be done?

cleszkie 07-17-2018 01:04 PM

Re: Drive too long after rebuild
 
You need to raise the engine/tranny combo with an engine hoist and shift everything forward. You should probably get new engine mounts while you are at it. This process might be easier if you unbolt the tranny from the engine first.

Its scary to think that the only thing keeping your engine from rolling around were your tranny mounts.


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