Synthetic rear end oil....

I have replaced the oil in the front axle, tranismission and transfer case with
synthetic gear oil.
The rear axle calls for a straight 90W weight, not the 75W-90W like the others.
I can's find any 90W synthetic. Those of you that have replaced the rear end oil, what did you use?
Thanks, Bill

 

i believe royal purple makes it. and with rp it already has friction modifier in it for the lsd.

 

I used 85W90 mobile 1 I have had no problem.

 

on my 06 trd offroad prerunner, with the rear locker, i used mobil1 75w90, no problems at all.

 

Do you have the LSD? (non-Auto LSD)

If Yes - you need oil + friction modifier. The manual should say how much it needs. Or - you can try getting gear lube that already had the friction modifier in it. Like mentioned earlier - Royal Purple and Amsoil Severe Gear also had the friction modifier in it.

If you don't have the LSD, you don't need friction modifier.