DIfferential fluids - Subaru OB

[tigerclaws]

Hi,

I was wondering what would be the ideal gear oils to use on my center and rear differential for a 05 OB. Previously I have used 75w-90 in both the differentials but I am thinking of changing it again. Should i go 75w-110 or 75w-140?

How long should the change interval be? My last change was 30k miles ago.

Thanks.....

 

[VK56VD]

As far as the weight of the fluid, I would stick to the factory recommended weight in your owner's manual. A lot have had success with the Amsoil Severe Gear lubricants.

Right now would be a good time to do the differentials again as extra insurance. It would be interesting to see how black the fluid will come out after 30k miles.

Please let us know of any updates if you do decide to do the service and what the color of the fluid was. You may also consider a used oil analysis on the fluid if that interests you at all.

Good luck!

 

[Eddie]

I ran Mobil 1 synthetic 75/90 for 120,000 + miles and never a problem. Changed at 15K, 30K, 90K. Probably complete overkill after the 15,000 change.

 

[Solo2driver]

My Impreza really liked the 75w-110 AMSOIL Severe Gear, as well as the Motul Gear300 75w-90. Both pricey, but both excellent shift quality. Subaru OEM is also good and about the same price.

 

[friendly_jacek]

You might want to read this:
https://bobistheoilguy.com/forums/posts/1134810/
My sub also developed a whine with 75W90.

 

[SubLGT]

Originally Posted By: Eddie
I ran Mobil 1 synthetic 75/90 for 120,000 + miles and never a problem. .........


M1 in the rear differential of my Subaru had sheared down to a SAE 85 weight after only 10,000 miles.

 

[SubLGT]

Originally Posted By: tigerclaws
Hi,

I was wondering what would be the ideal gear oils to use on my center and rear differential for a 05 OB. ........


do you have a manual or auto trans?

 

[sprintman]

I have Redline 75W90NS in OB manual g'box and 75W90 in the diff. D4ATF in p/s