Differential gasket failed in less than a year?

[ube91]

Happy New Year, everyone.

The 318i decided to give me a nice surprise for 2023... Took it out of storage to replace the air filter and plan some other fixes before selling the car to allow myself to focus on my M4 and my Z3 M. What I didn't expect was my diff. gasket to fail. I replaced it around June of 2022, so I have no idea what could've caused it to fail so early. Don't know if this has something to do with it but I did have to use a coating of gasket maker to get the thing to stick into place as I did the job with the diff still on the car.


BTW all of those stains are not from the diff. They're from old oil leaks I've had in the past.

[hopeful]

Not sure where the oil is coming from but if it's coming from the seals check for a plugged vent. If it's not and it's coming from the actual gasket than there's a workmanship issue. Is it a cork gasket? If so torque specs need to be followed.

[TobyB]

Rear cover gasket? Try snugging it gently.

Then replace with RTV and done.

t
bought one gasket once. Never again

[moatilliatta]

Yeah, I quit using those gasket because they were always damaged in shipping.

Check the flatness of your cover too. Grey Right Stuff works well, don't go crazy because it will get blended up in the diff oil if you do. You'll see how much it squeeze's out.

Did you replace your speed sensor oring?

[jbontke]

Grey Right Stuff works well, don't go crazy because it will get blended up in the diff oil if you do.

How does it get blended in the diff oil? If you give the Grey RTV time to fully cure, it should be fine. Are you saying the diff oil breaks down cured Grey RTV?

[moatilliatta]

Any RTV. I don't know how much I've picked out of oil sumps pick ups from people plastering it on gasket surfaces. Esp when not needed.

[digger]

BMW sell a loctite product 5203 for this purpose I thought it actually replaced the actual gasket. Bmw p/n 83190422969

Also seems to be loctite 5970 bmw p/n 83190404517

[zaq123]

good quality gasket that's installed correctly won't leak.Paper works much better than cork IMHO. I always coat the paper gasket with thin oil film (run it between oily fingers) and this eliminates all scraping for any future cover removals. On diffs without drain plugs (older jeeps, toyotas) where one has to remove the cover for the fluid change, this method even allows to reuse the gasket for one more fluid change.

If your cover/diff flange has scrapers from previous jobs - leaks can develop.

I hate RTV. Minor scrapes can be addressed with Permatex high tack coating of your gasket. It never hardens and can be removed with the solvent. If you really have to go RTV route - Hondabond is the best RTV, period. Any excess won't brake off inside as many other RTVs do. Probably more crucial for engine cases but still...