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gatorv · 11-08-2013, 12:31 PM

2000 Alpine coach.
Not near motorhome to look this up.
Can anyone tell me what rear Diff oil to use and how much?
Is it synthetic or not.

Thanks Gator

Old Scout · 11-08-2013, 12:41 PM

Facts and opinions vary here but its 80-90 [hypoid gear compatible], about 4 gals [fill to top plug level], use synthetic if you want but think you would do better to just plan on chging it out every 50K miles [that's about 4 years for me] or so and not worry about it.

Algoma · 11-08-2013, 12:44 PM

Spec. says 85-140 meeting GL5 . Original wasn't synthetic but I don't think it matters what you use.

Old Scout · 11-08-2013, 01:03 PM

Spec provides several options--including both 85-140 and 80-90, both based on low temps. No upper temp limit specifications. Conversation with senior WRV maint mger prior to factory closure indicated 80-90. Interesting: Monitor axle specs doc recommends oil change every 100k miles or annually--which ever comes first. Unlikely that any of us do this.......

Algoma · 11-08-2013, 02:42 PM

The Alpine Coach manual for 2000 specifies 85-140 and only requires checking and topping up, does not specify replacement. I changed mine 5 years ago and the mechanical used 85-140 without asking so I assume that is normal for these axles. I use 80W-90 in my car and I am sure it would be OK in the Alpine too.

gatorv · 11-10-2013, 09:18 AM

Thanks for your input. Gator

Dave Fernandez · 11-10-2013, 11:24 AM

Make sure you use a severe duty/heavy duty differential oil, and I would recommend you use synthetic oil.

Algoma · 11-10-2013, 02:22 PM

When the original manual was written GL5 was the current standard. However, now there is J2360 which includes all the GL5 standard and a lot more. See "Beyond GL5" for more info. Interestingly Valvoline 75W90 synthetic gear oil meets J2360 but their SynPower Full Synthetic 75w140 Gear Oil does not (but still meets GL5).

tjshively · 11-27-2013, 09:36 AM

Drain & Charge Gear Oil to Lucas 70W90 Synthetic - 4 gals from Amazon.com
I always use synthetic in the dif because it does not absorb water and it provides better at high temps.

Algoma · 11-27-2013, 09:59 AM

I already have Delvac 1300 Super in my engine and Delvac Synthetic ATF in my transmission so I think I will round it up and use Delvac Synthetic Gear Oil 75W-90 in the axle. This does meet the new J2360 spec.