I just installed a salvage 208; replaced front and rear seals. After 2 days, the rear is now leaking. I assume a worn output shaft could cause this but not after only 100 miles. Case runs fine, no noise or vibration. Is there some trick to installing the seal? Anything else I should check before replacing the seal again?

 

There is a seal that runs on the yoke as well, that could've dried up and be giving you these problems, i know my dad has had this problem.

 

Try a Lucas Oil's leak seal additive for now, but it's only a band-aide fix at best. The yoke off the out-put shaft should remove with one nut(center of yoke, after drive-shaft is out) and the seal will pup out with a small pry-bar(careful not to scratch the surface when removing the seal. Use a seal driver to install a new one, and re-install the yoke. I use blue loc-tite on the threads myself. Not a hard repair to make, and the seal probably only runs about 10-15 bucks.

 

a slip yoke seal will almost always be a little wet around the shaft and may form a drop at times. you could have dented the seal slighty when drving it in causing a leak.

lucas oil products are snake oils, when run in a test they made oil not to cling to things as well and created more air in the oil causing lack lubrication issues.

 

OK, pulled the drive shaft, replaced the seal with a unit without a hood and discovered that the leak is not around the seal but from the inside of the yoke where it slides over the output shaft. Since the slip yoke is hollow, it can't be designed to seal. Is there another seal on the output shaft before the rear seal? I'm sure I am missing something simple...just not sure what it is.

 

no seal on the driveshaft yoke if that is what you are refering too? it is just welded or machined, you may have a hairline crack if that is the case

 

74F250, thanks for checking back...I'm not sure about the engineering on the case but from what I can see it looks as though the rear seal is designed to seal only the outer surface of the slip yoke of the drive shaft. The problem appears to be that fluid is coming out between the output shaft and the inside of the slip yoke on the splined shaft. The output shaft has a 1/4" hole in it... I'm wondering if there is a plug for this or if it is only a surface dimple. Alternatively, is there a seal for the output shaft on the cone of the rear of the transfer. It just doesn't seem to make sense that the fit between the slip yoke sleve and the spline shaft would act as a seal to prevent fluid from pushing past...

 

Hoping someone can still help.
Thanks

 

Fluid is supposed to get into that space where the splines are between the slip yoke and t-case output shaft. Fluid should only leak from the seal area itself unless, as stated above, you have a hairline crack somewhere. Put everything back, clean up the area, drive it a little bit and check the area again to see where the leak is coming from.

How much of a leak are we talking about anyway? Wetness, a couple of drops, or a puddle? Check the vent/breather tube to make sure the unit can breathe, otherwise it may force fluid past the seals. Check the fluid level too, just in case you haven't..........

........and keep posting......good luck.

Check out my gallery.....posted a pick of pulled slip-yoke when I pulled the t-case.

 

The fluid is coming out the back of the slip yoke through the hole in the sleeve where the yoke ears are attached. Is there supposed to be a plug in end of the the sleeve? It apears to leak as much as 1/2 a pint after driving for any period of time. As it leaks it throws fluid around on the frame tail pipe etc.

 

when you state the yoke ears, you are talking about the u-joint ones? If that is the way i am reading it and you are stating it is leaking behind the u-joint, there is no plug.

The u-joint yoke is welded onto the splined hollow shaft that slides onto the transfercase output shaft.