Output Yoke Leaking!

[formulaross]

My '94 Chevy is leaking tranny fluid. Got under it and looked and tranny fluid is leaking through the center of the output yoke and running down and off the universal joint. Is there a replaceable plug in the end of the output yoke, like a freeze plug on an engine, that has corroded?

Thanks,

Rick

[CatDiesel_762]

Are you truely sure its leaking from the middle of your dirve line slip yoke? Or does your transmission not have a slip yoke?

I think it would be more your Pinion Seal on the Transmission Output Shaft.
If you have a bolted on yoke, (meaning the driveline can come off and the yoke remains on the transmisson), then you may need to remove the bolt and use some RTV on the splines and underneath the washer. While you are there you might has well replace the the Transmission Pinion Seal and possibly a crush sleave. They should only be a few bucks more and only take a few minutes to replace. Don't forget to Torque everything back in place with RTV on the edges of the splines and underneath the washer.

[formulaross]

Okay, I may have confused the issue with incorrect terms. I have a '94 Chevy pickup, 2WD, auto tranny, 4.3L Vortec. Looks like I have a male splined tranny output shaft with a female splined output yoke that slides over it. I fully expected to find the seal between the tranny output housing and the sliding yoke to be leaking. But, the outside of the cylindrical portion of the yoke is bone dry and the seal is dry. The red tranny fluid is dripping off the end of the yoke that holds the universal joint cross-piece. If I feel up in the universal joint area (where the projected axis of the tranny output shaft would intersect), the end face of the yoke is wet with tranny fluid. All I can imagine is that the output yoke forging is hollow (and open-ended) so they can broach the internal splines (to keep costs down) and then they seal the end of the yoke with a cap or something like a freeze plug and this is what is leaking. Or, is there a slightly different construction to this assembly that I'm not realizing? Thanks for the help, I do appreciate your time and comments, Rick.

[FCFFUZZYFACE]

yes the slip yoke can leak, what you have is a porous stamping. You can try to clean it and seal it but the only sure cure is to replace the slip yoke, I would replace the seal and ujoint while I was there.

FCFFUZZYFACE

[formulaross]

This is what it turned out to be. The slip yoke was sound and not porous. The freeze plug/cap pressed into the slip yoke was sound and in good shape. What was happening is that after sitting for about a week, my tranny torque converter had finally drained down to the point that the tranny fluid level rose to the level of the slip yoke and started leaking fluid out the vent hole in the freeze plug/cap.