What causes trans fluid to leak through the center of the driveshaft yoke? The leak is not between the yoke and the seal or the seal and the case, the fluid is coming from the center of the yoke, only when the car is parked on a slight hill, not running.
had the same problem with my sw pitch th400 also after sitting for several days I was told to remove the shaft and slip in to the inside bottom of the yoke a peice of rubber with some silicone pack it down and let dry ,to stop the bleed down Dave
I have the same problem, I have a new rear seal and I parked on a slight hill and within an hour I had a puddle of trans fluid. Is this only on switchpitch tranny's??? Tim
Leaks Guys: There are two (or more) types of yokes generally used on the TH-400. I suspect you have the type with a hole in it. The type with the hole in the middle is longer and supposed to seal on the inside of the trans with an O-ring. The other type is shorter, has no hole and needs no sealing O-ring. If you can, it is best to replace the O-ring or the yoke to the type compatible with your trans. Homegrown repairs may not last. FWIW: I have a spare trans in one of my cars with the wrong yoke and a homegrown repair(a wad of paper towel stuffed in) that has yet to leak. ou: Jim
hmmmm..... I have the same exact leak problem, when my car is in the driveway which is sloped a bit, there's a nice puddle of fluid. while parked in my flat garage, no leak. I'm glad i did a search brcause i was litterally going to go replace the rear seal, but after reading this that might not be my problem. Since I'm partially retarded (Sicilian), I'm not exactly sure what you guys mean above.... you're saying to pull out the driveshaft and look at the yoke. Since mine is leaking, I probably have the longer type yoke with the hole in it and will need to put on an O-ring. Is that is o No: ? VinMan out...........
If your yoke has a hole in it then I suggest that you clean the yoke real well inside and out and put some good silicon sealer over the hole on the outside of the yoke (there is not much room in between the u-joint and the yoke so you will need to use a small screwdriver or something flat to smooth out the silicon over the hole) and put some on the inside of the yoke way at the bottom over the hole, I used the black gasket sealer and mine does not leak anymore. The O ring is located on the shaft in the tranny. Your O ring could be shot or you have a different yoke on the driveshaft. Tim
yoke I Had The Same Problems But The Problem Is That There Are Fat And Thin Yokes Diameter Wise . I Had The Original Tranny In My 67 LeSabre And It Died So I Put In A Used Tranny But Original Yoke The Yoke Was To Thin And Did Not Allow A Tight Seal Arond The Yoke So I Had To Find A Thick Yoke
I had the same problem. A friend told me this process, it worked for me. I took out the driveshaft to look at the yoke. It had a lot of space on the end with no splines in it. That means it has an "O" ring on the output shaft. So support the trans, take the bolts out of the mount, take the crossmember out, or slip it back out of the way (mine laid on the dual exhaust). Take the rear housing off. You'll see the "O" ring. Replace it, put it all back together. Worked great for me!! Also had a leak in front, same guy loaned me his tool to replace the small seal where the shift linkage goes through the main housing, and gave me a seal. I put that one in, and had a dry trans thereafter. I thought the front seal was leaking, and was very glad to be was wrong.
