Hot Rods Question on GM 350/TH Trans front slip yoke

Ya the 350 T/H Transmission Has been gone for a long time but many still use them in their old cars. the slip yokes were used for many years with the GM T/H .Now someone tells me these slip yokes 27 spline w. the gap are (not) all the same on all the T/H Trans; is this true If so how are they different ?? Gene in Mn

 

The missing spline was to allow a sealed yoke, cuz the yoke slides in and out a little with the rear end movement. Some of the yokes had a small hole in the end of yoke by the UJoint. This was for the movement but this one didn't have a missing spline. There was a ORing somewhere up in the housing that would seal the ATF from leaking out. I one time put a yoke with the little hole in it in a trans that was suposta have the no hole- missing spline yoke. It leaked Trans fluid bad, cuz there was no oring in trans. This is all from memory. Hope it helps.

 

Yep, the yoke with hole will leak.

 

They were made with internal and external U-joint retainer clips. You can get mix and match U-joints to put internal clipped yokes on external clipped drive shafts and visa-versa.
They also make light and heavy duty ones. Found that out the hard way. Grabbed one to use to measure up the drive shaft length for our stock car. When the drive shaft came back we saw a beefier one on the shelf. Used that one and the drive shaft barely fit. The extra length came at the base of the yoke where it is beefier as it spreads to accept the U-joint.
A little RTV will fix the ones with the hole.

 

The TH350 may be gone, but the 700R4's used the same yoke, so they're still extremely plentiful to locate new or used. And I see them for sale as 3.5", 5", and even 7" lengths. Often a slightly short donor driveline can be used by simply buying a longer yoke. I've even bought 7" and whacked them off to get the exact length I needed.

 

Thanks much will be ordering one Don,t like returning the wrong thing as I ,ve done so many times in the past... Gene in Mn

 

This is a Turbo 400 short shaft that didn't get put away right when I s****ped the trans making it worthless but it has the O ring ahead of the spline.
Quick question, do the "sealed yokes have a couple inches of smooth space inside the yoke before the splines start?

Then I went outside in this miserable wind chill and took a photo of a yoke with missing spline while looking for one with the recessed splines.

 

I've never seen a TH350/700R4 yoke with any smooth area at the front?

 

The O ring shaft TH400 trans yoke has about a 2" smooth bore before the splines started. There were also bolt on yokes in some Corvettes and trucks. There was also the TH375 that had a 27 spline yoke in the early 70s.

 

As to Mr48chev's question..... found on another thread.

 

I seem to remember the Powerglide is the same as a TH350 no?

 

Nor have I.

 

That may be certain 400 yokes only then.