SoAlVette

I don't see many of you out there talking about Lucas differential gear oil. I see a lot of Red Line, Royal Purple, Mobil 1 users. I was always of the understanding that the Lucas products stood up just as good as the above mentioned. Also no need for limited slip additive. Thoughts?

charliet615

Well, it would be interesting if someone would chime in, I'm curious as well.

c4cruiser

I think it's a matter of personal preference for gear oil. For the diff in my '87, I use a good grade of GL-5 rated 80W-90 gear oil and the GM Posi additive. For my '02, I use Mobil-1 products; synthetic ATF in the trans and synthetic 75W-90 for the diff.

One benefit is that I can get them all locally. Never had any lubrication-related issues.

WVZR-1

I don't see anything in the Lucas "propaganda" that mentions "no additive required" for limited-slip" it only mentions - "super slick" and "resists squeezing out". I don't think I overlooked it. Maybe?

There's absolutely no reason that it should be considered less than desirable but for some the availability might be a challenge and it's not advertised to the extent that others are. I've a friend who uses many Lucas products - he also I believe collects some "contingency monies" also. Sometimes that requires more than just "the decal"!

SoAlVette

This is what they say on their website:

This Lucas pure synthetic gear oil is a super-slick, long-lasting lubricant that is designed especially for heavy-duty or high performance applications where regular gear lubricants just aren't good enough. It contains a special additive package that increases lubricity and insures less gear noise and longer bearing life. Lucas pure synthetic gear oil is also designed to stand up to high temperatures without losing its lubricity, making it excellent for use in limited slip differentials.

I guess that means no additive is needed. It was my understanding that all synthetic gear oils do not need an additive.

Mr. Peabody

I don't think that this is correct IMHO. I've always used Amsoil products in my engine, trans and rear diff but I still put the GM additive in the rear diff. I tried it without the additive first .... however when taking a sharp 90 degree turn I was getting tire chatter .... after the additive no chatter. Just my experience. I've never had any lubrication problems with any amsoil products.

WVZR-1

From "THEIR" web-site:

http://www.lucasoil.com/products/dis...id=12&loc=show

It appears that you've maybe created the making it excellent for use in limited slip differentials

Did I pick the incorrect product? You mentioned Synthetic 75W-90

Do they have maybe "multiple web-sites" with different product descriptions? If so. Why? There's a good bit of a good many things that are "assumed".

SoAlVette

Got that from the summit website. You are correct, different descriptions at different locations, makes you wonder

c4cruiser

I think that regardless of the brand selected for diff fluid, it's a simple matter of installing it and driving the car and see how it works. If there is chatter, add some Posi additive.

PLRX

My differential builder told me to stay away from synthetic oils, and to use Lucas 85W140 on the differential. I've been using Lucas 85W140 on all Vettes with no issues.