Rear Diff Fluids

What rear diff fluids do y’all use? Brands and weight? Are some better than others with your experiences? I’m planning on doing my first rear diff flush just to get all the “break in” debris out at 10k, thoughts?

 

https://www.tundras.com/threads/rear-diff-maintenance.114197/#post-2943642

 

Make sure it's GL-5, not GL-4. Synthetic is best...75W-85. I like Ravenol oil for my diffs. My 4x4 took just under 4 Qts.

 

Valvoline 75w90 from Walmart.

 

Red Line. And don't look back. And sail away for 100,000 miles.

 

Amsoil 75W-110, next change after 60k interval will be either Amsoil or HPL 75W-110.

Several years ago, the allowable viscosity range for 90 grade gears oils was split into a lower and higher levels -- 90 and 110 grade. So any gear oil with 110 would have been a 90 grade before the change.

 

Mobil 1

$39 75w 90 GL-5 Limited Slip, Ultra Long Drain 500k Miles, Manual Transmission, Gear/Differential Lubricant (1 Gallon)

75w 90. 10 bucks a quart from some no name place so I bought 250 bucks worth lol. If no mobil 1 I use schaeffers

 

^Also Mobil 1 75w90. Was using Castrol 80w90 after I installed an auburn LSD but when the warranty expired on the LSD I went back to Mobil1 - with additional friction modifier of course.

 

High Performance Lubricants (HPL)

 

85w-140 Lucas non synthetic per ECGS recommendations. Used it in my Nissan, GX460 and now my tundra.

Synthetic gear oil thins out when hot which isn’t good for differentials. While conventional clings on to the gears keeping them cooler longer. Even the Walmart cheap stuff is great. Just change every two years and you’re good. I do mine every springs cause I enjoy it haha and it’s cheap.

https://eastcoastgearsupply.com/files/PDF Files/ecgs-gear-oil-recommendation1.pdf

 

Conventional doesn't cling to the gears better, and synthetic doesn't thin out at higher temps anymore than conventional. These are myths. I know what ECGS says, but they're not oil experts. If synthetic thinned out and didn't cling to gears then it wouldn't be used worldwide in the racing industry and every other vehicle in the world.

 

They build differentials for a living and do testing consistently. And the racing world changes fluids after every event haha

Use what makes you happy inside. OP asked what people are using and I posted what I use. Don’t get offended when it’s not something you agree with. Makes no difference to me…

 

I just don't agree with incorrect info

And yes, you posted what you use. Then made absurd claims. OP asked what people are using, not false claims.

 

Wow

Use what you like and believe any oil related info. Geez I shouldn’t have said anything. Oil threads are stupid people are too sensitive