Differential Fluid Change Question (About RTV)

[JEEPCJTJ]

Ok, somebody tell me why there just isn't a simple drain plug?

Here's my differential drain plug version of how everything happens in assembly line manufacturing. I don't remember exactly what inspired me to write a similar version for another topic 25 years ago or how many other versions I've written since then. If only I would have thought about cut and paste and emailed them to myself. Anyway. It shouldn't be too hard to figure out who to trust and why.

The accountant decided that any threaded holes and pipe plugs cost too damn much and had to be eliminated. The engineer said that's crazy, the lube needs to go in somewhere and out somewhere else. While they argued about what should be what and where, a designer suggested that the fill hole was needed just enough to require a rubber plug but the drain hole could disappear. At that time the accountant came up with the idea that a handful of skinny little rubber plugs should be enough to hold the cover on and save even more $$ by not threading those bolts and holes and of course the fill and drain holes still weren't needed. The engineer had already had enough of hearing this crap and said that was a great idea and replaced the bolts on the accountants differential cover with plugs. He didn't even remove the threads from those holes. A couple days later the accountant paid a high amount for differential repairs but he still hated the cost of any threaded holes and plugs (and the engineer) so he sided with the designer which resulted in one unthreaded hole and a rubber plug.

 

[hosejockey61]

Some people say they like to be able to see the condition of the internals.
Which has some merit, but who looks inside their engine when they change the oil? And the people that do inspect their diffs, how many times do they see anything worth noting?
Maybe take a look once in a while, but every time is unnecessary.

For a DD that never goes off-road, not a biggie to inspect all the time. For rigs that go off-road all the time, I think it's necessary especially if you do a lot of water crossings. A simple inspection will also allow you to replace gears/spiders BEFORE they fail.

 

[Jeepin' Geo]

I’ve been using Permatex Right Stuff (black) gasket maker on diff covers as an alternative to RTV for years. It’s easier to apply, not as messy, seals very well and when it’s time to pull the covers again, cleans off easier than RTV.

It comes in a pressurized can and cost more than RTV but well worth it IMHO.

 

[pagrey]

I think some people misunderstand the purpose of the drain plug in an aftermarket diff or Rubi Dana 44. It is just designed to reduce the spillage and mess when you remove the cover. You still need to remove the cover and clean the divot in the bottom of the diff where all the crap collects and inspect the gears. It ain't an oil pan and shouldn't be treated like one. I have a drain plug in my 42RLE, it just makes the process easier and cleaner. It doesn't mean I can skip the real work.

 

[Blackjack]

I use either Ultra Black or Grey. Put a film on both the cover and diff housing, wait a minute or two for it to tack up, bolt together and fill.

 

[smcnich]

When I installed my Yukon Ultimate 88 kit two months ago, I finally switched to a lube locker gasket. Only cost a little more, but it was extremely satisfying to know I wouldn’t be spending anymore time scraping RTV off the diff and cover again. That’s the most time consuming part of the whole process. It’s worth the extra like $20 it costs over a tube of RTV in my opinion.

 

[rasband]

I think some people misunderstand the purpose of the drain plug in an aftermarket diff or Rubi Dana 44. It is just designed to reduce the spillage and mess when you remove the cover. You still need to remove the cover and clean the divot in the bottom of the diff where all the crap collects and inspect the gears. It ain't an oil pan and shouldn't be treated like one. I have a drain plug in my 42RLE, it just makes the process easier and cleaner. It doesn't mean I can skip the real work.

At least in the Rubi Dana 44, it can be a good tell since the drain plug is magnetic and, if nothing else, will give a good sense of metal shavings in the diff. That’s not just making it easier and cleaner, it’s giving a possible symptom to investigate.