RICE ETR

iTrader: (3)

Ok so i am pulling out my T56 and putting the 400 in. I bought a yoke for the tranny locally and will have the same place make me a driveshaft.
So am attempting to measure my d/s but the guy at the shop told me to make sure the yoke goes all of the way into the tranny. Mine however still has a 3/4" gap when it bottoms out and then of course will be 1.5" out once installed with a correct length d/s.
Can anyone please let me know if somethings up with my set-up or am i ok to run this yoke with the depicted amount of yoke hanging out.





All of the way in


Pulled out .75" after bottoming out, a total of ~1.5"

john kilgore

your trans is a truck, very good. a car would allow the yoke to go up to the seal. push yoke all the way in, measure length, subtract 1/2-3/4" and you have your length good luck

RICE ETR

iTrader: (3)

Thanks for the reply...so the last pic is what things will look like once in the car...this is ok??

RICE ETR

iTrader: (3)

Ok...here's the scoop for anyone who wants to know. Truck tranny's have a bolt on yoke and so have the slip joint in the center of the d/s. I a yoke with the first 1/2"-3/4" of the splines to be machined off to make the ID of the yoke greater than 1.375". Strange/Denny's etc are all out of stock of this modified yoke so i am having the yoke shown above machined locally.
After talking with a few different tranny shops, running the yoke as depicted is not recommended due to increased tail housing bushing wear.

8a8mfh

iTrader: (3)

Thats not a modified yoke, it a plain old th400 slip yoke, sure you can have say a 4x4 slip yoke modified to match the specs.
Thats one very relavent pic you left out is the one of the open end of the yoke.
All short th400 tail shafts are much the same, only difference I've ever seen was a solid shoulder vs one with the o-ring groove, some have two o-ring grooves. Bolt on or not they all have threads.

Dirty 30

iTrader: (96)

Back from the dead!

Question:
What is the purpose for that black O-ring on the tailshaft?

forcd ind

iTrader: (7)

some of the yokes had a pinhole in the back by the u joint, to allow air out as the yoke moved in/out-the o ring sealed the yoke so trans fluid did not leak out the hole-was a common problem way back when to have a leak with a mismatched yoke/o ring output shaft/seal-i think 4 wheel dr (transfercase) also used the seal
i remember when the 700r's came out, the splines were tight, used to have to pull the driveshaft out every now and then and grease the splines, or you would be sitting still and the d/s would suddenly "pop" or move when the air went out, you would swear the guy behind you bumped you
a new yoke should have light grease when installed, but few do

Dirty 30

iTrader: (96)

Thanks. Looks like im going to have to get my yoke counterbored to slip over that O-ring area. I might as well look into getting a new DS since my old one is a little bent.

Dirty 30

iTrader: (96)

just thinking out loud, wouldnt it be better to sand down or machine down the bump where the o-ring is so the yoke can slip in rather than boring the yoke?

jakeshoe

iTrader: (14)

Jesse,
The o-ring prevents fluid from leaking past the splines to go out the back of a non-sealed yoke.

Many slip yokes have a small hole in the back to let air escape as it compresses in and out under suspension movement.

The shaft is very hard and it has to be machined for the whole length to allow the yoke to travel past the "bump" you see. The shaft diameter must be smaller than the inner small diameter of the spline.

Dirty 30

iTrader: (96)

ah ok, well i went ahead and just had the yoke bored this morning. Im on my way to pick it up. Thanks again Jake, I'll let you know how the tranny you built me works out.

jakeshoe

iTrader: (14)

Cool deal,
Did Driveshaft King take care of you? I may have to have one bored for the '69 Bird I'm doing the 6.0 motor in, gotta try out the driveshaft today in it.

Did you get a chance to look for the car coils? Let me know on that, I may be running down to south Dallas tomorrow.

Dirty 30

iTrader: (96)

Actually took it to a machine shop, i was just calling you to let u know it worked out well. I'll call u later today about those coil packs.