Slip yoke for transmission

[cleetus]

Does your yoke 'sink' all the way to the rear seal on the tailshaft housing?

Just got my driveshaft today (with a new yoke) and it won't sink far enough to allow me to place the rear U joint into the rear yoke. I have roughly 1.5-2" of pinion still showing on the yoke, and it WILL NOT go any further.

I went as far as removing the tailshaft housing on the trans (700r4) and checking for obstructions. I measured the yoke fully seated which was 4.25". I measured the inside of the yoke and had 5.75" of possible travel. Even if I could fully seat it at 5.75", the yoke could not get hung up on anything on the output shaft.

Ever hear of a yoke that wouldn't seat like this? I can't find any visible burrs inside the yoke that could be hanging it up, so help....

 

[80montecarlo]

you should have a minimum of .75" of the machined surface installed extending past the output shaft seal

 

[cleetus]

Right, the problem is that the yoke will not go IN further. I need the yoke to go INTO the tail housing that extra inch so I can put the u joint into the rear yoke.

 

[cleetus]

Here are pics of the problem:

This is the yoke FULLY SEATED. I can not press the yoke on any further:

This is the rear yoke with the front yoke fully seated, showing I need only 1/2" of inward travel on that yoke to get the rear U joint on.

Here are pics of the yoke fully seated on the tailshaft, the distance it seats, and the available travel of the yoke:

So you can see where the problem is. My question is- should that front yoke be able to travel until it hits the rear seal on the tail housing, or are the yokes supposed to only go in 4.25" and stop?

 

[t5montecarlo]

You should be able to push the yoke in until it touches the seal.

In your pictures, the yoke slides over the shaft until the spline stops. Is the diameter of the lower grooves smaller than the diameter of the shaft after the spline stops? If so, that is your problem.

Is the rear diff suspended? or are the jacks under the diff? If you suspend the diff, you may have better luck fitting the driveshaft.

Is that the same driveshaft and yoke that you took out?

Did you use the same driveshaft with the 700R4 and 8.5-inch diff before?

What is the length of the driveshaft between the centerline of the u-joints? It should measure 48.5 inches.

 

[cleetus]

Center to center is 48.25", so it's a perfect fit.

I used my caliper to measure the spline part vs non splined part of the output shaft and the splined part is actually thicker. There is no way the yoke is hanging up on that area.

My old yoke and driveshaft has been donated to the car gods since it was bent, blew up my old trans, and caused a massive headache.

The rear is free hanging in that pic...tried that method and failed

It can only be the yoke. The stock 350 yoke from the old driveshaft, and the yoke prior to that were fine.

I told the guy at the shop I needed a yoke for my 700r4, which is just a typical 350 yoke. He said, ok that's a powerglide yoke then. Is the PG yoke different that a stock 350 yoke? It is possible the yoke I got is tapered to get smaller the further in, but it might also be an optical illusion. If it truly is tapered, then the yoke is incorrect and will never work.

 

[mean78malibu]

There are 16 and 27 spline power glide yokes. The th-350 is also a 27 spline and interchanges with 27 spline PG yokes. However, the 700R is different (fits 700R and 4l60) even though it is also 27 spline. Check out the link below, this could very well be your problem.

http://www.dennysdriveshaft.com/c75_general_motors.html

 

[Malibu355]

How far does your output shaft hang out from you tailshaft seal? Does it hang out about the same distance that the yoke is short of going all the way in the housing? IMO you shouls always install a driveshaft with the rearend on the jackstands as if your car was sitting on the ground. If you cant get your driveshaft in the pinion yoke that way, STOP because something is wrong and you will tear something up. You had also said the depth of the trans yoke but you did not mention if it was splined all the way to the total depth. Is it?

 

[cleetus]

Thanks for that link. It appears the yokes ARE different. It appears they make a 700r4/4L60 yoke by itself. They also have 5 or 5.5" yokes. BIG differences.

And fwiw, the yoke they sent is smooth for the first .25" then splined the entire way through.

The output shaft hangs roughly 1/2" out of the tail housing.

 

[t5montecarlo]

I suspect the spline is not fully properly broached the full length, although you can see the spline right the way through. Can you borrow a different yoke, preferably an OEM yoke and see how far you can insert it? The yoke is likely your problem.

Both of these URLs show the same yoke for 27 spline Powerglide, Turbo 350, 700R, 200R and 4L60:
http://www.dennysdriveshaft.com/p54_powerglide_and_t_350_transmission_slip_yoke_1310_series_27_s.html
http://www.dennysdriveshaft.com/p52_powerglide_and_t_350_transmission_slip_yoke_1310_series_27_s.html