NP 231 Leak

[nagal]

Lets start with this weekend I did a SYE install on my transfer case. Everything seemed (key word there) good no problems.

Today I get ready to leave for work. I see a lot of small stains on the driveway underneath the rear of my Jeep. Closer look show the front and part of the bottom of the gas tank covered in something. I wipe my finger across it and smell it, no smell. Looking even closer I see where some of the stuff is pooling (no dripping just pooling getting ready to drip) on the gas tank. It is a thin red fluid.

Now I am assuming it is ATF due to the SYE install but I do not see any visible leaks on the case or rear output shaft housing. I did not have a whole lot of time to look as I needed to get to work. No I did not drive the Jeep today

Seeing as how fluid is getting flung all over the underside I am not sure where to start looking for the leak or should I just consider tearing it all down and re-sealing the case and output shaft housing?

[TJSUPE]

ONe thing to check atleast would be the speedo gear. When I did mine I didnt realize that the o-ring on the gear went bad and when I re-installed it, ATV fluid seeped out of there.

[nagal]

Supe, I will make sure to check that out.

My thought is somehow ATF is leaking out onto the driveshaft and as I drive the spinning of the driveshaft is flinging ATF all over. But that seems very odd but the only thing I can think of.

[TJSUPE]

I think that is normal actually. I thought my pinion seal was leaking becuase there was fluid all over my rear diff and dripping off of it too. Once I fixed my speedo gear, there was no more fluid over my diff.

[nagal]

I think that is normal actually. I thought my pinion seal was leaking becuase there was fluid all over my rear diff and dripping off of it too. Once I fixed my speedo gear, there was no more fluid over my diff.

Wow, that describes what is happening to me to. Did you have to go to the dealership to get the o-ring or were you able to find one at the autoparts store?

[TJSUPE]

I ended up going to the dealership. It was a few bucks I think and they had it on stock. I first went to a autoparts store and they stopped carrying those o-rings.... wierd.

check Stu's site. He was the specs of the O-ring incase one of the parts stores in your areas have O-rings.

[nagal]

Thanks for the help Supe, hopefully this will be the problem.

[blkTJ]

could be the seal between the output shaft and yoke. check the yoke nut, if it's wet, that's probably your culprit.

the fix is to remove the yoke, apply rtv to splines, reinstall yoke.

good luck.

[nagal]

could be the seal between the output shaft and yoke. check the yoke nut, if it's wet, that's probably your culprit.

the fix is to remove the yoke, apply rtv to splines, reinstall yoke.

good luck.

Thanks Brain, I will check that also. Would be nice if its something simple...

[nagal]

Found a leak but not the leak

I found a leak near the shift rod plug on the rear output shaft housing. It was not easily visible as its above the fill plug so it would only leak after I drove it.

O-ring on the speedo looked good, no tears in it. I have one on order so will replace it anyways.

Yoke nut was nice and dry, no signs of ATF.

What I did notice is:

1. The splatter pattern is all behind the rear axle yoke
2. Little red globs of goo

So my theory:

When I got the new drive shaft, the ujoint at the axle end was covered in this red gunk. Seeing as how the splatter is all at the axle end and there is little red globs on some parts, this red junk got flung all over. As it heated up it melted into a red liquid that I mistook for ATF.

Is this the case? I am not sure.

I need to pull the rear output housing and reseal it but for now I ran some rtv around the area that leaks. I am hoping this will hold until I get the time to fix it proper. If the temp fixes holds and I see no significant lose of AFT at the transfer case then I expect to see the red drippings around the rear axle disappear after a few days

[mparker]

You definately have a leak.

If it isn't the O-Ring on the speedo gear (been there done that) and it isn't a lack of RTV when you mated the case, then it is probably the seal on the output shaft.

It was a pain trying to find this leak, but once I put my fingers on the seal and it sank back I found my problem.

I later found out from talking to others that I wasn't the only one that had this problem, most of the people that installed the Teraflex SYE (also sold as a rebox from Pro-Comp) ran into this. All i had to do was add a little RTV to the seal and i was good to go. See pic below.

[Black & Tan TJ]

When I got the new drive shaft, the ujoint at the axle end was covered in this red gunk. Seeing as how the splatter is all at the axle end and there is little red globs on some parts, this red junk got flung all over. As it heated up it melted into a red liquid that I mistook for ATF.

Is this the case? I am not sure.

Yeah I get that stuff all the time, it's the Mobil1 syn. grease I use, red in color too and will drip at times. Maybe a wipe down and see what comes back. This mostly happens to me only after I lube everything.

Just a thought, B&T TJ

[nagal]

mpaker, I checked the seal last night and it was nice drive and firmly in place but when I tear the rear output housing off to reseal it, I will give the seal area a little more inspection.

Tom, I did wipe everything down fairly well last night. So crossing my fingers and hoping that was it.

Drove into work this morning (45 miles) and my temp fix is holding, no leaks that I can see. I will crawl under it tonight once home and check for sure.

Thanks everyone for there input it has helped a lot.

[freewaydan]

When I did mine, it was leaking up the output shaft and over the nut. Some white grease and reinstall and it was fine

[cjdirtbiker]

Had to pull my rear DS at the end of the rubicon trail to tighten the output shaft yoke nut. It had come loose about a half to three quarter turn and fluid was leaking out onto the driveshaft. Tightened 'er up and no more leaks.
Chris Fields had a big socket in his toolbox.