best fluid for differentials?

[LedFloyd900]

I recently bought my '92 runner and im going to do a little tune up (change differential fluids, oil and filter, plugs, transmission fluid and filter) and I was wondering if there's a certain fluid that's best for these differentials? I play in the mud and water quite a bit if that makes any difference. thanks for any advice!

 

[KidVermicious]

If you're in the water a lot, I'd use the cheapest 75w90 or 80w90 you can find.

 

[Mirakuu]

Advance auto sells a 5 gallon bucket of 80w90. I got that and had plenty to get the diffs, trans and xfer case. Working good so far and not bad for $60. They had it in the back and I had to ask for it. It's not usually out on the floor.

 

[3rzrunner]

If you're in the water a lot, I'd use the cheapest 75w90 or 80w90 you can find.

I agree changing the fluid more often is always better when you wheel because crap and water will always find its way in there. If you want to use a better fluid try the AMSOIL severe gear 75w-90 sig. series its what I run in my diffs and tranny but it is on the $$$$ side

 

[02SE]

The best I've found for parts longevity in an extreme use Chrisman 12.5 differential, is Redline's Heavy Shockproof gear oil. I wouldn't run that in a 4Runner though. For that I'd use Redline's 75w90.

If you are getting water into your axle on a regular basis, I would extend your breather as high as necessary to keep the water out.