differential fluid

albass · January 14, 2012

Went for an oil change the other day i have 76,00 on my 2005 Tahoe and they recomend that I change my differential fluids and replace with new. Now I know about doing the tranni especially since I tow a boat but never thought about differentials needed to be changed just make sure there full????

DaveH71 · January 14, 2012

Yeah, it would be a good idea since you tow and it is probably the stock fluid in there. There is gonna be alot of metal shavings if it has never been changed.

Gurrzt · January 14, 2012

use a full synthetic 70w-90.

Sierra in the Sand · January 15, 2012

Don't the lockers use a special fluid???

00Silverado4x4 · January 15, 2012

Don't the lockers use a special fluid???

No, you do not need any additves with the locker (G80). The additive is for limited slip units which are not in the trucks. Synthetic 75w-90 as per owners manual.

Gurrzt · January 15, 2012

Don't the lockers use a special fluid???

No, you do not need any additves with the locker (G80). The additive is for limited slip units which are not in the trucks. Synthetic 75w-90 as per owners manual.

+1 on that, I added the "additive" anyway, could not hurt.

txab · January 15, 2012

Don't the lockers use a special fluid???

No, you do not need any additves with the locker (G80). The additive is for limited slip units which are not in the trucks. Synthetic 75w-90 as per owners manual.

+1 on that, I added the "additive" anyway, could not hurt.

Some additives can "hurt". That's why they say not to use them......

Gurrzt · January 15, 2012

Don't the lockers use a special fluid???

No, you do not need any additves with the locker (G80). The additive is for limited slip units which are not in the trucks. Synthetic 75w-90 as per owners manual. +1 on that, I added the "additive" anyway, could not hurt. Some additives can "hurt". That's why they say not to use them......

I should have been more specific as to what additive I used, it was the small GM additive that is used in vehicles with LSD. I purchased it from the dealer, and told them what vehicle I was adding it to, and what options were on the vehicle (in this case G80).

Mossyoakglock · January 15, 2012

The G80 is not an limited-slip differential and does not need the additive. It's been discussed here under multiple threads. They also use the RPO code G80 in some of the cars (previous gen Camaro is one of them I believe) for their rear axle. So unless you specified that the G80 was for a truck and not a car, they might have assumed it was for the LSD in a car, which needs the additive.

Please correct me if I'm wrong.

8.1HD/ALLISON · January 17, 2012

Sounds right to me, no additives needed for G80 because as stated it is not a limited slip, it is a gov-lock. I try to change diffs and transfer case fluid every 25000. I think factory reccomends every 30000.