Advice on Interval for Transfer Case/ Rear Diff Fluid Change
 

Hello all. I am looking for some advice on when the transfer case and rear differential fluids should be changed in my 2010 Outlander. I have searched this and other forums and have been unable to reach a conclusion. Even Mitsubishi seem unsure. The owners manual for my vehicle states that for severe usage maintenance schedule transfer case should be changed at 30k/24 months but rear diff only needs oil level checked. However, when I look at Mitsubishi's online service tool it states that both transfer case and rear diff are to have 'oil level and condition checked' at 30k.

The dealer seems to think leaving them both until 60k should be ok, but if I do decide to change the transfer case I should also do the rear diff. This confuses me even further... why would mitsubishi recommend the transfer case but not the rear diff. Does the transfer case get subjected to more stress than the diff?

I have the 30k service scheduled for this weekend so I am trying to figure this out before then... do I do just the transfer case, both the transfer case and rear diff or neither? I am planning on doing the tranny fluid regardless and the other 30k service items. The dealer seems to think that 'checking' the fluids is not really worth doing as once they are at that stage for labor they may as well replace.

Incidentally I am at 30k and 48 months so technically by the word of the manual I should be doing the 60k/48 month service I guess but in the past I have been advised to prioritize mileage over time so that is the logic I am following... hopefully its sound. I dont really have the money to change coolant on top of everything else!

Thanks in advance for the assistance.

Not that I recommend following my procedure, but I'm at 100k miles now, and have never changed the transfer case or rear diff. oil. I am doing it soon, and did do the transmission fluid at 60k. I wouldn't think you'd need to replace the transfer case and differential oil at 30k. If it gives you peace of mind and you have the money to do it, it's not going to hurt.

Hello, I have changed my diffs both front and rear pumpkin. I removed the cover and sprayed the whole inside with carb cleaner...can per each... until shiny n new. My fluid was stagnate and had to be changed. That was at 100k. I seemed to of knocked off the breather hoses and got some water inside so it had to be done. I did check it at reg. intervals 30k and was good and I didn't even have to add any at that time. The transfer case was also good and I have 130k on it now so I won't change it at all. Let us know how ya make out.

I changed mine out at 60k. Glad I did. Old stuff was really dark. Put mobile1 in there and has been good since. Last checked at 130k and hasn't darkened much at all. Going to wait and see if it'll go to 200k.

On your 2010, you do not have a front diff, just the tcase and rear. Front is integrated into tranny. Always remove fill plug first so you can be sure you can get fresh fluid in. You'll want to be sure you have a hand pump with a flexible nozzle to get this done....I don't know how it would get done otherwise.

Thanks for the input everyone. Sounds like it is not critical to do at 30k and could wait until 45k or 60k. A couple of questions for those that have changed it: Was there any metal in the oils? And did it seem like the transfer case and rear diff fluids had worn at the same rate? If the transfer case fluid had worn more quickly then perhaps I should do that and skip the rear diff for now as suggested by the hard copy of the manual that came with the vehicle. Still confused as to why the manual and dealer/ online service tool differ on whether they both need to be done at the same time.

This work will be done by the dealer as dont have the capability to do it myself.

In my opinion, i'do do both and have a local shop do it. You will be needlessly raped by the dealership. This is not rocket science...any shop can do it.

I also noticed the book never says to change the rear diff fluid.

The transfer case may be a harder working piece. Considering the rear diff normally do not see a lot of torque in tarmac mode...

I think the Transfer case and rear diff uses a little different fluid, what did you guys change it with?

I am probably going to put in redline or amsoil at 30k. The initial change might be the worse.. However, the black color might be the grease they use during assembly? If anything, I am hoping the synthetic stuff will cause a little bit less drag and better gas mileage.

Many people neglect the rear end and actually, it isn't too bad, the RWD Lexus we have, never have the rear diff fluid changed either and it is about 150k miles and which transfer 100% power to rear wheels. They don't really specify changing it also.

I just changed both my rear diff and transfer case and used a syringe with markings on it. They each took about 0.52 L, so 1 qt is not quite enough. I used the redline application guide and they called for slightly different fluids so I had 2 qts anyway.

yeah, one supposedly takes straight 80w and the other straight 90w.

I'm at 191k miles now. My 75w90 change at 60k is still going strong.

I used a qt of 75w80 and a qt of 75w90