GM Machanic Help

[Skywalker]

I had called a local tranny shop here yesterday and the guy said we call it stuffing a yoke. RTV/CLOTH/RTV and he had no explination of why it does this. I'm OCD and although I'm only a shade tree machanic I like to do thing the right way and I didn't like that answer. I figure as you say, just because it works does not make it right. I need to understand what is wrong before I can fix it correctly. I'm just that way and I'm not knocking anyones info on the fix for this problem. I just put in a new modulator valve just for chits and grins a hour ago and the old one was most likely good for there was not fluid and all hoses are tight on each end and no leakes. I would also like to focus on the fact that when this happens, it's like an explosion of puke because that little hole should just drip, but leaving a 1 ft wide 4 ft long path as he gussed against the universal joint tells me there was alot of pressure built up. I'll keep reading and asking till I'm happy with the answer that gets me going toward a fix!

Just because "it works" doesn't mean it's the proper fix. I've seen PLENTY of things that worked that I would never even consider doing on one of my own vehicles.

 

[Skywalker]

Perfect info here, Photo's to boot that makes it eash in crayola style for me! I'm sure the inside rubber seal is the problem and I not at all afraid to go to my local tranny shop and get a seal. Go to the Auto Hobby Shop at the AF Base as is only a few dollars an hour to rent a lift and then take that rascal appart as described in the links. Replace the seal and go from there. If that still doesent fix it, JB Weld will work for me but I'm betting that seal or O Ring is problem. Many thanks to all.

If oil can leak past the 6" of tailshaft/yoke splines to the weep hole at the end of the yoke and leave a quart of fluid on the driveway every time it's parked on an incline and the converter drains out, I'd be willing to wager air could do the same. I see no problem whatsoever eliminating the weep hole.

However, looks like there is plenty of fuss over this on multiple other forums. There's an additional seal on the tailshaft that is most likely bad:

Leaking Driveshaft Yoke

4L60E Tailshaft Sleeve

transmission fluid leak

 

[SKnight]

What happens is the clearance between the splines of the output shaft and the yoke open up some and the fluid can get past it. A new yoke usually fixes it simply by tightening the clearances up. It can also be plugged up with cardboard and silicone, once sloppy it will vent to the case OK. The pressure on the thrust surfaces is a concern, so that's not the recommended fix.

The bushing in the tail housing being sloppy contributes also, the yoke falls to one side and opens up a way for fluid to leak.

Also make sure to check the vent hose for the trans. If plugged up when parked the pressure rises now that the cooler isn't doing anything and then pushes out the easiest avenue of escape.

 

[Skywalker]

Good info as well as I will be going to the tranny shop today and shoot the chit about this and see what I want to do but I will fix it one way or another. As always, thanks to the many big brain people of the best Org on the www.

What happens is the clearance between the splines of the output shaft and the yoke open up some and the fluid can get past it. A new yoke usually fixes it simply by tightening the clearances up. It can also be plugged up with cardboard and silicone, once sloppy it will vent to the case OK. The pressure on the thrust surfaces is a concern, so that's not the recommended fix.

The bushing in the tail housing being sloppy contributes also, the yoke falls to one side and opens up a way for fluid to leak.

Also make sure to check the vent hose for the trans. If plugged up when parked the pressure rises now that the cooler isn't doing anything and then pushes out the easiest avenue of escape.