75w90 Safe to Use in Rear Diff.?

[SR77]

I am going to replace the fluids in both the front and rear on my 96 Explorer V8 AWD. I decided to go with Royal Purple and an using 75w90 in the front. I have been told by a few on Bobistheoilguy.com that 75w90 is safe to use in the rear also even though it is suppose to get 75w140 because the syntetic royal purple 75w90 has a Timken Rating of 100+ which is an extremly good rating for a 90w and equal to a 140w. It would also give me alittle better MPG, especially in the winter. Would the 90w be safe to use in my rear diff and are there others on here that have put in a 75w90 in the rear without any problems? Don't want to order the wronf stuff and then have to dump it out. I only tow my Quad around so i don't do any heavy towing. Thanks for the help.

 

[snocross1985]

I use Mobil1 75w90 in my rear axle. You will not have any problems with the Royal Purple 75w90.

 

[SR77]

Thanks for the reply. How long have you be running the 75w90 in the rear? I am planning on keeping my explorer for a while and am hoping that running the 90w will not cause problems down the road. Anyone else run the 75w90 in the rear?

 

[aldive]

I run AMSOIL Series 2000 Synthetic 75W-90 Gear Lube with no problems.

Dead Link Removed

 

[Rhett]

I also have been runnin' AMSOIL 75W-90 in the rear diff for a year and it hasn't blown up on me yet...
I'm getting better mileage than ever, too...

 

[snocross1985]

I've had mine in the rear diff for about 6 months now, zero problems.

 

[Explo01]

I kinda have the same question except I used 95W140. Will that do any harm to it?

 

[SR77]

Thanks for the help. I guess I am going to go with the RP 75w90 for both the front and rear diff. then. Hope nobody posts because they are starting to have problems running the 90w in the rear anytime soon.

 

[Explo01]

I wish I had discovered this post before I put in the 95W140. My gas mileage is at it's worst. I'm getting like 10 mpg!!! I had to learn the hard way

 

[elkhunter]

Is the 75w90 okay to put in if I have an Eaton Posi?