Transfercase rear output shaft oil seal

Cacti_Ken · Post by **Cacti_Ken** » Sat Jul 31, 2010 3:52 pm

I don't know why, but the rear seal on the T/C started leaking pretty bad. All this was new about 2500 to 3000 miles ago.

The seal surface on the companion flange looks good.

I started removing all the components to get to the seal. I am down to the brake backing plate.

When I did all the retoring work it was on the bench.

Now it's in the jeep. Just looking for a little recomendation on wheather I should try and dig the seal out and replace under the jeep or remove the backing plate and speedometer housing and bring it out to the bench to do the seal replacement.

Post by **wesk** » Sun Aug 01, 2010 8:58 pm

Ken,
For me that would depend on what shows up as the cause for the premature seal failure.

Some failure causes to look for are dirt damage. If the felt seals are used as backups for dirt control and they aren't lubed on install they burn up pretty quick and let the dirt in.

Seal injuries during install can be delayed in showing themselves.

Wear as relates to shafts and their parts that affect forces against the seal.

If the third cause is suspected you'll have to pull at least that case.

Cacti_Ken · Post by **Cacti_Ken** » Mon Aug 02, 2010 9:03 am

I lubed the felt prior to install, and it still looks good. there wasn't any dirt. actually all was clean.

The seal housing, the metal face part of the seal is dented in one spot. Looks like I may have distorted it on install. That may be the reason it failed. I looked at the parts diagram, and notice a gasket that goes in before the seal. I don't remember putting that in. I put RTV on the splines. There wasn't any oil coming from that area.

Well, just got to get it out and put another in. I think the easy way to do it is to take the speedometer gear housing out and onto the bench and try to do a better job of installing the seal this time.

Post by **wesk** » Mon Aug 02, 2010 1:58 pm

If the new seal comes without that little skinny round gasket just smear a very light coat of sealant on the rim of the seal case that lays tight to the inside corner of the housing.

Cacti_Ken · Post by **Cacti_Ken** » Mon Aug 02, 2010 6:23 pm

I had some spare seals, & gaskets too that came in the gasket seals package.
the new seal is in the freezer waiting install. I may get back on it tomorrow.
the seal surface on the companion flange is good and the seal feels like a snug fit on the flange.

The shaft measures 1.552. hope that is in tolerance
and the seal is 1.479

Post by **wesk** » Mon Aug 02, 2010 8:40 pm

Your companion shaft should be just fine. Was your output shaft end play set correctly between 0.004 and 0.008?

Cacti_Ken · Post by **Cacti_Ken** » Mon Aug 02, 2010 9:22 pm

Yes, I took pains trying to get that right. I believe it was .005 in the end result.

Cacti_Ken · Post by **Cacti_Ken** » Mon Aug 02, 2010 9:29 pm

I'm going to remove to pan and shine a flashlight up in the gears. I think this is the third oil drain I have done on it. There is always silver color in it. I figured it normal at first during a break in.

I'm getting more concerned about that. And there was some brass in the seal area. There isn't any noise when running, so don't know what to think right now.

maeserik · Post by **maeserik** » Wed Aug 04, 2010 2:06 am

Ken, when you replace the seal, in the meantime renew the brakelinings if they are contaminated with oil, they can take much oil before you discover the leak.

Erik

Cacti_Ken · Post by **Cacti_Ken** » Wed Aug 04, 2010 8:50 am

I washed the brake linings with gasoline. they look clean to me.

Post by **wesk** » Wed Aug 04, 2010 10:12 am

If the oil had a chance to soak in it is very difficult to get it all out. As the shoes get warm they will sweat out more and more oil. Not a real big deal on the parking brake but a real issue on the service brakes where the grabbing can hurt you. Several good soakings with spray brake cleaner and even a little baking time. Hot sun will do it then retreat until they stop oozing oil.

Cacti_Ken · Post by **Cacti_Ken** » Wed Aug 04, 2010 7:54 pm

Will the brake cleaning fluid cause the glue to come unbonded?

I figured a little contamination on those linings wouldn't be very critical either.
Yeah we got enough heat here without having to bake shoes in an oven. I'ts been hugging close to a 100F this week I only get under the jeep for just a little bit, No hurry.

Oh, by the way, I also removed the brake baking plate and speedo gear housing to bring to the bench to replace the seal. A lot easier that way.

I took the pan off the T/C. Did an inspection of the gears. Didn't see anything to be alarmed about. So I'll be putting the speedometer gear housing and companion flange back on tomorrow.

I pulled the speedo gear off, now I'm not sure which end goes on first. Hope I can determine from a picture in the book.

Post by **wesk** » Wed Aug 04, 2010 8:38 pm

It might dissolve glue if it gets that far.

Cacti_Ken · Post by **Cacti_Ken** » Fri Aug 06, 2010 1:56 pm

thanks Wes, I had it right, but gotta be sure though.

I'll put the brake shoes out in the sun and see if they bleed any oil first.

EDITED: 8/8/10

It all back together and filled up with oil again. Will make a test run soon.