I did not change the washers. They haven’t leaked.

 

same here....no washers, no leaks. And you don't need Mitsubishi oil....any 75w90 would be sufficient.

 

I've got a 2016 Outlander, parts guy gave me 90 weight gear oil for both transfer case and rear differential. My owners manual says 80 of both but parts guys says it has changed and that's what they use now.
Thoughts?

 

Depends on your climate. If it gets below freezing you’re way better off with a multi-weight. I think I used Redline 75w80 and 75w90 but 75w90 would work for both. Check your manual but I think it needs to be GL5 Hypoid gear oil.

 

Like I said I bought mitsubishi gear oil from mitsubishi parts counter. They gave me 90 for both. I'm in the Chicago area. I'm curious as to why mitsubishi changed this. Were they having problems with the 80 weight?

 

BTW with only about 29k the front transfer case fluid was pretty dark and dirty. The rear wasn't nearly as bad. We do a lot of family trips so I plan on changing these fluids once a year as preventive maintenance.

 

This is also correct for 2016 sel 3.0l v6. You can use a regular socket and ratchet for the fill plug if you use an extension.

 

I have Outlander 2016 SE ,I ask Mitsubishi dealers when differential oil need to be change one say 30000 other 60000 mills. In the manual don't say clear when too. May I have opinion on this subject from the forum.
Thanks

 

Bit of an update: Redline faired much better than the factory fill. I had ~95,000 kms on factory fill, the diff looked awful, kinda grey. I put 70,000 on the redline, diff was a bit darker than the new stuff, transfer case looked pretty similar to the new stuff. Redline seems to have changed their recommendation, I had a partial qt of 75w90 marked transfer case, they now recommend 75w85 for both.
The transfer case fill bolt is not bad if you have a socket and ~5 inch extension. A pump is the way to go to fill these. I think I got mine off amazon, maybe from redline online.