Transfer case leak

[JMT]

Hey guys,

Installed the JB SS SYE a couple months ago. Noticed low fluid a week ago. Looked good the following few days. Then I went on a long drive at highway speeds. Got home and fluid was all over the skid plate and rear diff. It looks like this.

It could be leaking from the case or the SYE. My inclination is it’s the SYE because of the way it’s all clean underneath and looks like it’s been weeping, and only after that long drive at highway speeds. Any thoughts on the leak location?

 

[Apparition]

Could snug the SYE to tcase bolts a bit and see if it improves.

 

[freedom_in_4low]

did you put RTV on the output yoke threads/nut when you put it together?

 

[Lou]

It looks like it’s coming from the speed sensor. My speed sensor recently failed, they sent me a new one free of charge. The new one was very loose in the bore compared to the old one. It was leaking. I swapped o rings and it’s a little tighter but still not as snug as the old one was. I sent them an email and they haven’t responded. It hasn’t leaked since I swapped o rings.

 

[Apparition]

did you put RTV on the output yoke threads/nut when you put it together?

Does look like atf on the shaft seal.

 

[Lou]

Does look like atf on the shaft seal.

you're right it does. I would clean it up real good and take her for a rip and see what you got.

 

[mrblaine]

you're right it does. I would clean it up real good and take her for a rip and see what you got.

It is the shaft seal. The area from both sides of the seal all the way across is clean and shiny below from the fluid running out of the seal.

 

[Jason from SoCal]

I had to track down a transfer case leak... I had some luck with putting white baking flower onto the transfer case and seeing what turned red.

From the photo it looks like the shaft seal is leaking. I assume the shaft seal came pre-installed in the SYE kit. Did you lube it (apply grease/oil/atf) before installing the yoke? Because of how dry the yoke looks, it appears like it may be leaking between the seal body and the housing (not between the seal/shaft). At the 7-o'clock position on the seal, it looks like there may be a crease/crack in the seal body itself. Take a close look in that area. Finally, is seal fully seated? Every SYE is slightly different, but I'd expect the seal to be nearly flush with the housing. The photo appears to show yours protruding significantly. You should be able to confirm that the seal lip is riding down on the machined yoke surface.

(photo for seal depth reference, note is is flush with the housing and you can see 3-4mm of machined shaft past the seal lip)

 

[JMT]

It is the shaft seal. The area from both sides of the seal all the way across is clean and shiny below from the fluid running out of the seal.

So, just remove the nut and RTV it and the seal? Torque back down to 170ft/lb’s IIRC?

 

[JMT]

did you put RTV on the output yoke threads/nut when you put it together?

I did, but I may not have got enough on there. The RTV I used was designated for TCases and was gray and a bit runny. I usually use the black stuff like for the diffs. This stuff I didn’t like at the time bc it was thinner.

 

[Lou]

I did, but I may not have got enough on there. The RTV I used was designated for TCases and was gray and a bit runny. I usually use the black stuff like for the diffs. This stuff I didn’t like at the time bc it was thinner.

If this was the case your oil leak would be coming from between the output shaft and the yoke. Oil would be slung all over the place. Your leak is from the seal that is set into the SYE housing.

 

[JMT]

If this was the case your oil leak would be coming from between the output shaft and the yoke. Oil would be slung all over the place. Your leak is from the seal that is set into the SYE housing.

Well, the red stuff is all over the place. literally

 

[JMT]

It looks like it’s coming from the speed sensor. My speed sensor recently failed, they sent me a new one free of charge. The new one was very loose in the bore compared to the old one. It was leaking. I swapped o rings and it’s a little tighter but still not as snug as the old one was. I sent them an email and they haven’t responded. It hasn’t leaked since I swapped o rings.

I had already grabbed a bit thicker O ring bc I did have an early leak there in the first sensor (that didn’t work), so that is all good now. Thanks

 

[mrblaine]

Well, the red stuff is all over the place. literally

Yes, but look at the origin. That clean and shiny area tells you what is going on.

 

[bobthetj03]

Dude, look at the first photo you posted. It's the seal!

 

[JMT]

Dude, look at the first photo you posted. It's the seal brah!

Yes, but look at the origin. That clean and shiny area tells you what is going on.

Yeah, that’s what I thought. It’s what I said in the OP too! I called it the SYE.

“ My inclination is it’s the SYE because of the way it’s all clean underneath and looks like it’s been weeping,”

Just getting some more eyes on it. Thank you. Is the seal bad? Or do you have to RTV it? I just can’t remember everything I did in the install. I’ll have to go back and brush up. Just tired. Lots of work these days and little time. Thanks!

 

[JMT]

Ok, removed the nut, yoke, and seal. Seal was still good so I put some gray RTV on it, the splines, and nut and torqued back down to 200ft/lbs.

As one can imagine, the Savvy Skid was terribly Grungy inside, so I removed, cleaned, and re-installed. Thanks for your help!

 

[Apparition]

Ok, removed the nut, yoke, and seal. Seal was still good so I put some gray RTV on it, the splines, and nut and torqued back down to 200ft/lbs.

As one can imagine, the Savvy Skid was terribly Grungy inside, so I removed, cleaned, and re-installed. Thanks for your help!
View attachment 193866View attachment 193867View attachment 193868

Skid needs more scratches.

 

[JMT]

Skid needs more scratches.

I keep trying, we just need some harder trails!