Rear Differential Gear Oil Comparison?

[DR1]

Redline,Maxima,Motul are all made with ester base synthetics. I emailed Amsoil and they would not share any info with me regarding if theirs was ester base.

So do you think Valvoline Syn-power 75w140 compares in quality at all to the following I already mentioned in 74w140?

 

[SwampSurvivor]

Gear oil is gear oil is gear oil. There may be slight differences between add packs in different engine oils, but with gear oil there's just not enough of a difference.

 

[aquariuscsm]

Use Amsoil Severe Gear.

 

[DR1]

Use Amsoil Severe Gear.

Why???

 

[aquariuscsm]

Why???

I tried several different ones, and Severe Gear was hands down the best. Spec is 80W-90, and I used Severe Gear 75W-110.

 

[DR1]

I tried several different ones, and Severe Gear was hands down the best. Spec is 80W-90, and I used Severe Gear 75W-110.

If gear oil is gear oil then how could you tell the difference?

 

[aquariuscsm]

Gear oil is definitely not gear oil. Add packs differ between brands. Mobil 1 was really whiney, Redline whined as well, RP was really good cold, but got a little whiney when hot. Severe Gear was silent. Amsoil AGL 80W-90 was just as smooth and silent as Amsoil Severe Gear, but I went with Severe Gear to get the broader 75W-110 range and the higher end add pack.

 

[double vanos]

I used Valvoline SynPower 75w140 in my ‘11 F150 with 3:73 gears and no problemo! Was in there for over 40k miles before I traded it. IMHO it’s fine.

 

[Deleted member 89374]

Gear oil is definitely not gear oil. Add packs differ between brands. Mobil 1 was really whiney, Redline whined as well, RP was really good cold, but got a little whiney when hot. Severe Gear was silent. Amsoil AGL 80W-90 was just as smooth and silent as Amsoil Severe Gear, but I went with Severe Gear to get the broader 75W-110 range and the higher end add pack.

With AMSOIL Severe Gear is not so much about the additive package as the base oil. High-end gear oils are blended with Alkylated Naphthalenes, and I believe that's the case with their SVG line of gear lubes.

 

[930.engineering]

Redline,Maxima,Motul are all made with ester base synthetics.

Would you please stop repeating that nonsense?

Gear oil is gear oil is gear oil. There may be slight differences between add packs in different engine oils, but with gear oil there's just not enough of a difference.

Actually? So you're using GL-5 in your automatic transmission and ATF or GL-3 in your diff?
.

 

[Lubener]

Go get some Supertech gear oil of the recommended weight. Your differential will not last any longer with those expensive products. Your differential likely would outlast your vehicle even with the factory fill.

 

[Gasbuggy]

FWIW after I switched to M1 75w90 my CTS-V diff started to chatter in the winter when making the first few turns.

 

[alcyon]

Use Amsoil Severe Gear.

Is it ok with open diffs ?

 

[Chris142]

Go get some Supertech gear oil of the recommended weight. Your differential will not last any longer with those expensive products. Your differential likely would outlast your vehicle even with the factory fill.

Mine didn't .. even with drain and fills every 20 k with synthetic oils.

 

[Deleted member 89374]

I emailed Amsoil and they would not share any info with me regarding if theirs was ester base.

AMSOIL is made with Alkalythed Naphtalines. It's a proprietary formulation, and it's very different than most other gear oils.

Go get some Supertech gear oil of the recommended weight. Your differential will not last any longer with those expensive products. Your differential likely would outlast your vehicle even with the factory fill.

That's a bunch of nonsense. It depends on how you use your vehicle, how big your differential is, and what oil capacity it has. The smaller and less oil it olds, and the hotter it runs, the better oil you need.

 

[Snagglefoot]

When you have 225,000 miles on your original diff, using a single product of your choice, come and tell us about it.

 

[CleanSump]

MB 300D with 348k miles on Amsoil gear oil after the first 30k. Still smooth and quiet when I sold it.
That proves something? No, that's an anecdote. Might be MBs are superior, might be the diff had an easy life, might be an angel on my shoulder, or might be because my wife had a Buddhist Priest bless the car when new. Shook water on it and everything just like the helo in the movie. Fact is, nobody actually knows why my diff lasted when running that particular oil. There is a correlation (diff lasted over 348k and oil brand X was in the diff), but no established cause and affect. Many will assume it was the Amsoil.
Current vehicles all run that oil. Why? Since the 300D did so well on it, I feel warm and fuzzy.

 

[UNC151]

Gear oil is gear oil is gear oil. There may be slight differences between add packs in different engine oils, but with gear oil there's just not enough of a difference.

Based upon what?

 

[Deleted member 89374]

Gear oil is gear oil is gear oil. There may be slight differences between add packs in different engine oils, but with gear oil there's just not enough of a difference.

Take Red Line gear oil, AMSOIL Severe Gear, Valvoline Full Synthetic Gear Oil, Mobil 1 Syn Gear, Dealvac 1 Heavy Duty Gear Oil, Castrol Syntrax Long Life, Castrol Syntrax Limited Slip, and I could probably go on for several more lines. Not only are all of these gear oils vastly different, but even different viscosities within the same product line are vastly different. For example, you can't blend 75W-140 the same way you do 75W-90 because if you do, your 75W-140 will turn into a solid at temperatures not too far below Zero Degrees Farenheit.

Then there are gear oils like Motul 300 GL4/GL5 75W-90 that can be used in a manual transmission, manual transaxle, and a non-limited slip differential. The formulation is such that it will not harm yellow metals, just like HPL's Differential Life product.

More importantly, if you have a non-limited slip differential, aka open differential, you still need to use a friction-modified fluid for better wear and temperature control.

I am sorry. However, you're mistaken. I would say that gear lubes are vastly more different amongst each other than many off-the-shelf motor oils.

 

[UNC151]

Is it ok with open diffs ?

Quite OK. Amsoil Severe Gear is arguably the best gear oil on the market.