Daddy o

Hello all. I'm in the process of changing my differential oil and need a recommendation on the best gear oil and friction additive. I've never changed the gear oil since new, so I figured it's about time. It's an 04 LeMans edition with 24,000 miles and stock rear end. No mods. Not a lot of miles but since it's 15 years old it has got to be getting tired now. No problems with the diff just plain maintenance. Also, Aprox. how much does it hold.Thanks in advance for your input.

'Shifter

Amsoil Severe Gear 75w90 and Slip Lock additive is the answer you seek.

glbeauchamp

3.6 pints. Amsoil comes in a squeeze pack and is real easy to install. That's what I use in mine.

Daddy o

Thank's Shifter and glbeauchamp. Is the additive amsoil also? GM serv. manual says add 4 oz with new oil, but everything in the manual is obsolete or supper ceded numbers. Makes it tough to find the right oil replacement on everything! Transmition calls for Dexron 111 now replaced by DexronV1. Don't want to put in the wrong oils an then have issues. Always had the trans. and engine done by a shop here. But now with my new Quick Jack they'll be seeing less of me.
Thanks guys, this forum is the best!

wscott62893

The Amsoil Severe Gear already has friction modifier added so you shouldn’t need to add anything if you go with that. That’s what I run and I don’t add anything. I never have issues with misbehavior of the clutch packs. I suppose you could always add a little more friction modifier if that bothers you.

Ditto on the squeeze bags. They’re SO much easier to use then a standard quart bottle.

byte_me

I run this in my 01 Z as well- I bought the hand pump for this and the ATF for the transmission - easy to do, great results. No need to add anything to the oil in my case, it has the friction modifier already in it. So far, runs perfect!

walleyejack

GM factory fill
unless it is a modified diff

GCG

Mobil-1 75W-90 Synthetic Gear Lubricant LS. Limited Slip Additive already included. for more info.