[77newell]

After the recent post about rear gear failure I thought it might be time to change that oil in my 93 coach. I had inintended to refill it with Mobil 1 75W90, then when I checked the Arvinmeritor site I found that oil was not on the approved list of oils though a companion oil Mobil Delvac Syngear was on the list. I donknow what makes the latter different. Other commonly available approved oils were Syn-Gear by Castrol and Valvoline HD Synthetic Gear EP.

IT seems there is a bit of a surprise and some learning every time I go to do something.

[Fulltiming]

Thanks Jon, I have added that information to my parts list.

[kyleb]

"IT seems there is a bit of a surprise and some learning every time I go to do something."

I could have said that ! ! !

[rheavn]

I got Castrol Syngear on Amazon.

https://www.amazon.com/Castrol-37507-Syn...ol+syngear

[HoosierDaddy]

Hmmm, I called Newell and they recommended Mobil 1 75w90.....
I am not familiar with the ArvinMeritor site. Is there something I should check out?.....I really don't want to change it again......!

[77newell]

Arvinmeritor is the successor to Rockwell. I used their website to see what was recommended.

I may have had Mobil 1 in it based upon a label indicating their products were installed at the factory.

I put Mobil 1 in the 77 coach I used to have and I saw no evidence that it was creating any problems. In fact, the few times I crawled under the coach while on the road the "pumpkin" seemed cooler that with the original 140 oil.

If I had put Mobil 1 in my 93 as you have done there is no way I would drain it, I would use it. I have not looked at the specs of the Delvac and Mobil 1 to see if there is any difference but that could be a worthy research just to sooth the mind.