MTFCA Forum

Just finished rebuilding Ruckstell axel. Assembled using Ultra Black as a sealer between the two halves. Finished and installed in car. Now I have a nasty oil leak at the bottom of the housing from where the two halves join. I can see it oozing about an inch or so along the bottom of the housing. What can I use to seal this up?

Only good way I know for sure is to open it up again. A new sealer is designed for gear oil that might be better than Ultra black for this application. Something like this. https://shop.advanceautoparts.com/p/per ... /7740016-P

Permatex No 2. Did you use a gasket?

Read this. The sealant John Z posted WORKS.
http://www.mtfca.com/discus/messages/82 ... 1542303309

Had same leak. Wiped the area well with lacquer thinner and dried.

Then ran bead of black silicone sealer over the area there and leak was stopped

Agree. Wipe with lacquer thinner and seal with black sealant. Not the best but every other fix requires taking halves apart that I am aware.

Funny thing - ultra black used to be good for that sort of thing....it's not like we use a gear oil with fancy additives and the like. I just sealed my pumpkin yesterday with the gear oil sealant - haven't put any oil in it yet. I'll be interested to see how well it works.

Have had to work until today. Took John’s advice and used the Permatex Gear Oil RTV. Was able to push a small Shem in the one inch space that leaked then covered with the Gear Oil RTV. No more leak!

This doesn't sound right to me if you were able to place a "shim" (?) 1" long between the halves and seal the outside of it. One side has a ridge and the other has a recess and they should fit together tight. From what I read, the halves are not engaged together properly. If this is true one half could be distorted from some type of damage and no longer round. Smearing gasket sealer on the outside might stop the leak for a while but will not fix the engagement of the halves. I can't see it and can only comment on what I read and based on that it doesn't sound like it is assembled correctly. It could just be a little nick on the ridge that a file could knock off and let them seat together.

I have rebuilt 2 Ruckstells and many other rear assemblies and never had one leak in the center. The two halves should go together completely with the paper gasket and a little sealer with no gaps or leaks. A "top coat" of permatex does not sound like a repair, the sealing should be in the seating joint and not the outside.

Tim Moore