Re-sealing D18 Rear Output Shaft

Edit: forgot to add, this is a 1968 CJ5 v6

Alright so my rear output shaft leaks like a sieve, so much so that last time I drove the jeep to work it left an embarrassingly large puddle of trans fluid on my parking spot (I was getting concerned texts for days, espcially when I took the motorcycle and co-workers thought it came from that). I went on to Kaiser Willys and reviewed the parts diagram and ordered the appropriate seals (https://www.kaiserwillys.com/diagram/dana-18-transfer-case-6/, parts 2, 45, and 4 just in case). I just finished tearing it all apart, down to removing the speedo gear housing from the transfer case. I'm confused though because there were 2 identical oil seals right on top of each other in the speedo housing, instead of the one listed in the diagram. I am assuming someone just..what, couldn't figure out how to take it out and sent it home? Or thought 2 were better than 1? Or is there a legit reason for there to be two? I think my case differs from the diagram anyway since I have the parking brake assembly to contend with, and I only have the one shifter (v6 dauntless jeep).

Any thoughts? Should I buy another seal and stack them like they were? Also, any advice on re-assembling to prevent further leaks. I was thinking about putting a thin layer of RTV on the very outside of the oil seals/inside of the seal race, and I think I saw somewhere recommended to put RTV on the shaft splines themselves which seems odd to me. Much appreciated.

 

Good deal, thanks for confirming. I guess she needs all the help she can get. When using 2 seals, do you use just 1 felt pad at the end of the 2nd seal? or 2 felt pads, one between the seals and one at the end?

If I re-assemble without the parking brake drum, will the bolts I pulled be too long or will they still work? The brake components aren't hooked up and the whole drum assemble is coated with about 1/4 inch of grease so I'd rather not re-install if I can avoid it!

 

Thanks, those seals look similar like what I'm removing. They definitely had the metal spring piece, and I don't think the ones from Kaiser Willys did. I have to look at the output yoke again, it didn't seem scratched but may have a groove in it.

 

Here's the output yoke. It feels pretty smooth to the touch, even the wear mark towards the end. My fingernail isn't catching on any parts of it or anything. I don't have a caliper handy to see if the thickness changes at all.

 

What Howard said "How's the surface of the output yoke? if it's at all scrtched/grooved you will leak "

Using two seals is often an attempt to seal a work out yoke. Most of the Jeeps I have rebuilt came to me in pretty bad shape and just about every one of them had transfer case yokes with the seal area worn down. If you can feel a groove in it buy a new one.

 

The yoke is almost always the biggest problem. They are cheap and easy to change.

 

National 450185 is what I came up with searching through this forum.
Real nice seal, or call Novak and see what seals they provide with their kits.
The National is $10-15 on Amazon, the tin can cheapo’s from FLAPS are $20-40.

 

Thanks everyone. After reading all the suggestions, I think I'm going to buy a new yoke. Since somewhere down the line a previous owner had already double-sealed it, I'm going to assume the yoke is the bigger unresolved problem. I was hoping to get it put back together today but I'd rather do it right than do it fast.

 

I always install the felts as I think they help keep grit from getting to the seals.

 

You have to re shim the output flange aswell. I find the shaft always has too much slop. I set them at zero lash or just a hair. Remove all the shims and hammer the race in as far as it will go. Set the housing on and measure the gap. Use that many shims and reassemble I use copper gasket spray on the shims aswell.

 

This.
I used spray copper on the shims, added a speedi sleeve on the yoke, and used Permatex Right Stuff everywhere else (including a light coating on the splines) and zero leaks!

 

I have had perfect success using the doubled seals. If the old yoke just has the one groove in it from running the single seal, the doubles will be riding inboard and outboard of that and will still work fine. I use SKF's 15655 for this and use wheel bearing grease on the lips when installing. As per Daryl, if the yoke is worn at the seal position(s), replace it or install a speeding sleeve and seal as in Doug's post above.

 

Thanks again for all who commented. I got everything back together today. I couldn't find any spray adhesive for the shims, so I ended up using a super thin layer of RTV on each shim and the mating surface (I ended up taking out one of the shims to make up for the extra thickness provided by the RTV). A contributing factor to my leak may have been the total amount of shims the PO used, as I ended up using less than what was on there. Taking out the brake drum made the re-assembly much quicker than disassembly and it looks a lot cleaner. I took it for a brief test drive and no leaks so far. My plan was for a much longer test drive but ended up cutting that short after I witnessed a bunch of drama at the gas station (cops were called, etc). I'll do a better test drive tomorrow but I'm confident the new yoke, new seal, new shims + RTV will take care of my issue.

Now on to the 99 other leaks, possible timing issue, accelerator pump issue, etc.