Amsoil Diff Lube Question(s)

[Kyle]

I've got a couple question before I change the gear lube in my Dana 80 for the 1st time. I've decided on Amsoil but don't know which one to buy.

"75W-90 Synthetic Gear Lube"
"80W-90 Synthetic Gear Lube (GL-4)"
"80W-90 Synthetic Gear Lube (GL-5)"
"Series 2000 75W-90"
"Series 2000 75W-140"

I'll be installing a Mag-Hytec cover at the same time.

I live in Arizona (115+ degrees in summer), but travel to altitude during elk season (20 degrees at night). I "usually" don't pull much but once in a while I drag a 12000# trailer.

Also, some gear lubes say "compatible with anti-spin diffs" but should I add the anti-spin additive anyway?

How much gear lube with the Mag-Hytec?
How much anti-spin additive with the Mag-Hytec?

Any help and/or opinions will be much appreciated.


[This message has been edited by Kyle (edited 12-29-2000). ]

 

[1tuffram]

Since you are going to use Amsoil, spend a little extra $ and get the Series 2000. As far as which weight it's toss-up. Some would say since you live in hot climate and occasionally tow you need the 75W-140. Amsoil wear test show both weights offer the same wear protection. The 75W-90 is more "fuel efficent". (4. 8% over petroleum)

As far as friction modifier, the Series 2000 has it added. Some people need to add additional friction modifier and some don't, guess it depends on your limited slip differential. I have never needed to add friction modifier, even when I used Amsoil's regular synthetic gear lube. I think this just varies from truck to truck.

Don't know the additional capacity with the Mag-Hytec cover. I'm sure Mag-Hytec and other members could give that information. I believe on the TDR Home Page there's an article under products tested which discusses the Mag-Hytec installation.

I think the 75W-90 will work just fine for your application, but if you are concerned about that occasional tow then go with the 75W-140 for peace of mind. I don't think the cold temperatures you mentioned will matter much, both lubes have a pour point of -51 F (-46 C). However, the Brookfield Viscosity @ -40 C, cP (ASTM D3829) for the 75W-90 is 35,000cP and the 75W-140 is 133,000cP. The lower a gear lube's viscosity (in cP), the better it flows in cold temperatures. Typical petroleum gear lubes where 138,000cP in the Brookfield Viscosity Test.

I'm sure oilman, amsoilman, and a few others can discuss this topic in much more detail if you need to know more.

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'95 2500 SLT 5 speed 4x4

 

[Sled Puller]

Ditto. You can not go wrong following what tufram said.

Also do a search, if you want more info.

Gene


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1997 Cummins Dodge 4x4 Bombed & Amsoiled. Amsoil Premiere Direct Jobber, Member of: NRA Business Alliance, GLTDR, WANTED: Wrecked Dodges.
www.awdist.com

 

[Mike Vonada]

Lets slide this one over the wall to the Products and Accessoreis forum.