Reseal Transfer Case Bottom Cover

The last area I could see leaking was from the transfer case. This was the project I took on last Sunday.

Some pretty obvious leaking here. Hope it is from the bottom plate

It’s recommended to make sure you have access and can remove the fill plug before starting.

Its hard to see, but I was able to get a lower profile 1/2″ wrench in the fill plug pretty easily

Then removed the 8 bolts from the cross brace

Then removed the cover bolts. Whoever was in there before replaced a couple of the bolts with stud/bolts.

Bolts came out easily but it took some work to pry the cover from its RTV seal without damaging the sealing surfaces

and cleaned up. Took a while to get all of the RTV off the surface and out of the holes.

Bolts needed to be cleaned up before going back in

Workshop manual recommends STC50552 on the threads which is Loctite 243. This is a medium strength thread locker with good oil resistance (versus the standard 242). Found the correct bolts to replace the stud/bolts at my local Home Depot

Used the Permatex product designed for gear oil

Followed the Permatex directions to re-assemble: Put the bottom plate on but only hand tightened the bolts until I saw the RTV start to bulge out. Let the assembly sit for an hour. Then, took each bolt out individually, added the Loctite and then torqued to spec. Gave the RTV 24 hours to set up before adding back in the oil.

Using this hand pump was the easiest and cleanest way I had to add the oil back in.

Will watch this area and hope that the leaks were from the cover seal. Fixing a leak in another spot on that transfer case will be a much bigger job.

This would be a good time to replace the oil in both differentials, but in my case that was done when I purchased the truck. Lubed the grease points as well and realized I should take on the upgrade to replace the two u-joints in the front double cardan unit with greasable u-joints. There is a lot of buzz on the forums about this upgrade, so will add it to the list.

Update: well….that wasn’t the area leaking. After de-greasing the transfer case, I could see that there was leaking from the transmission input area.

To get to these seals requires removing the transfer case, so I enlisted help.

Sam replaced all three seals in this area, and I now have a truck that is not leaving any marks on the garage floor.

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