silver74vette

I have seen a lot of posts about Diff Lube. I plan on changing mine and have Amsoil Severe Gear and additive that I bought for another car. Anyone use this? Results?

Seen a lot of Royal Purple and Redline reviews but no Amsoil in the eLSD.

Thanks, Chris

davepl

I'd stick with this:

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

If you MUST tinker with the fluid, make sure you add a friction modifier package that meets the LS specification, I think that's the important part. You can't just stick Royal Purple or Mobil 1 or Redline plus some generic bottle of "friction modifier" in with it.

In the other threads there WAS a choice that met the LS spec, I just forget what it was. But I think it's important to keep the LS additive package for the eDiff. I just can't prove it.

OnPoint

So what's the rationale for going with anything other than factory spec'd rear diff lube? Any data showing it is a problem?

Or are people just going on assumptions and hunches?

silver74vette

Are you assuming these other lubricants do not meet the factory specification? Just because it is not the part number called out in the owners manual does not mean it does not meet the spec.

I have this on the bench and have used it in the past (not on eLSD) with outstanding results. Was just looking for insight from the group.

I also am scratching my head as to why the GM lube costs $25 bucks a quart...

Case in point, I had the oil changed in my 2014 Sierra with Dexos spec oil at the dealership. When I changed to Mobil 1 (exceeds Dexos spec) my fuel mileage over that oil change improved over 1.6 mpg.

Bill Dearborn

The factory fluid is a synthetic like the others and runs about $20/quart. A refill of the eDiff with the diff cooler takes ~3 quarts so about $60 for a change. I don't see any reason to choose an aftermarket fluid, especially since the GM fluid seems to be an excellent fluid. The question is do it yourself or let the dealer do it. My dealership wants $150 to change it.

Bill

OnPoint

No. I don't know if they meet the spec or not.

Just wondering if they are actually better (or the flipside - whether the factory fill stuff has shown to not perform as needed), or whether people just think they're better cuz it's not the GM spec'd stuff.

madrob2020

Just had 3 qts of the GM specified fluid delivered today, gives me something to do while it is chilly/raining tomorrow. I'm sure all/most of you realize the GM spec stuff already has the limited slip friction modifier added so no other purchase of an additive required.

AORoads

my suggestion: put in anything you want after you read 'bikevette's' thread on ediff going out on him, and warranty tussle.* not saying yours is out of warranty if you put in some other company's stuff, but read down his thread to the cost to replace ediff. as I recall, it was 5K+. your car.

*Post 90, https://www.corvetteforum.com/forums...n-a-z51-5.html

silver74vette

I have read this thread and there is nothing in it that talks about using a different fluid so I am left to assume it was the stock fluid in the unit when it failed. My guess since GM did pay, it was a manufacturing defect.

Looking at the Amsoil site they do not have an equivalent for the Dexron fluid. Just looking for experience if anyone has used it.