I did a search and found a lot of info on the actual slip yoke leaking, but nothing like what I have on my truck. I just picked up this truck a couple of months ago, and one of the things that impressed me was how dry it was underneath. No oil leaks that I could find. I have put on almost 9,000 km and I am now leaking at the front yoke on the rear driveshaft. It seems to be coming out of the center of the yoke. At first I thought it was grease coming out of the u joints, but it got worse and now you can see that it is oil from the transfer case. The oil level is barely down, so it is not leaking much, but I would like to fix this. I have never seen a leak like this before, so am unsure how to fix this except for getting a new yoke, which I would like to avoid as I am short of funds at the moment. I also checked the transfer case breather tube and it seems to be clear. Any input would be appreciated.

 

That is really interesting in that the rubber boot is dry? Notice the drain hole in the boot is also dry. If it was the transfer case output seal the boot would be wet. Notice how the oil is after the balancer!I would suggest removing the drive shaft to rule out the trans case seal. Really easy, just four bolts on the rear yoke and it pulls out. Next shine a light in there and check how wet it is. Perhaps someone replaced the u-joints, lots of paint stick marks on the shaft? ( are these greaseable?) and lubed the yoke spline with too much oil, have seen it before. But from the photos I say the u-joint seal on one or another is shot and spinning grease out. Could you tell us how many miles on the truck, year, etc. Looks a lot like a reg cab drive shaft?

 

The truck is a quad cab short box. I think the drive shaft is pretty new, the u joints are nice and tight but non greasable. Also the entire drive shaft was pretty shiny when I first got the truck. It is not grease leaking, but definitely ATF. At first I thought it was the grease, but as the leak got worse, then I saw that it was ATF. It has slowly gotten worse over the last month, 5,000 km. The Transfer case oil is down maybe 1/4 inch. I am planning on pulling the drive shaft off tomorrow to get a close look.

 

Yah pull the drive shaft and check out the inside.Spray some brake clean in there. Why did the atf get by the balancer side? I'm sure from the picts that someone replaced that u-joint Anyway check it out and let us know. Don't sweat it a rear trancase seal is not bad to replace compared to a diff

 

The yoke is hollow with a seal to retain ATF - that's the source of leakage.

 

So there is a seal inside the yoke? I looked at the service manual for a 2003, but it doesn't show anything inside the yoke. I guess I will find out tomorrow. Thanks guys.

 

Outstanding info.........please take a picture of that would you

 

OK, got it all fixed up now, I think. Not much to it really. I was expecting something a little more complex.

Truck does not even come close to fitting in my garage.


Pulled rear drive shaft.


View inside slip yoke.


Cleaned it out and dumped a bit of gas in the slip yoke. I could see it seeping out around this cap.


Decided to split the u joint and remove the yoke for a better look.


Don't laught at my vise, it was free


Yoke removed.


Popped the plug out. Not much too it, and only a metal to metal seal.

 

Dug around and found some Moto Seal I use to seal the crankcases for 2 stroke dirtbikes, should work good here.


Goobered it up, ready to press it back together.


Back together.


And back in the truck.


And ready for work tomorrow


Needs a good wash.


And my helper

 

Good fix on the slip yoke seal - most folks don't realize ATF is inside!

 

Well, drove to Swan Hills and back, 307 km, didn't leak a drop. Glad I got that little issue cleared up. I hate oil leaks

 

You definitely have new u-joints. There's no way mine would've come out using just a vice at 75k miles. I needed a 10-ton hydraulic press.

BTW, nice looking truck!

 

Did this solve the problem permanently? I have the same problem except i didnt notice till it was too late and it cost me my T case "that thing was toast".

 

Ya, it's started leaking slightly again after 25,000 km. I'm going to have to pull it again and do something different. Might just get a new yoke if they are not too expensive.

 

That looks like a freeze plug in the end... maybe try a new one before buying the whole yoke.