makxc50099

well i tried the search and it failed to work.
i have a 2000 trans am WS6 and want to change the rearr end fluid. i live mostly in FL so i was going to get the 80w-90 but i wasnt sure if i needed to additive or not. i still have the stock rear end.

thanks in advance.

matt

01Z28M6

GM recommends the additive for the occasional "rusty screw" sound the Torsen Zexel can make and not to modify differential slippage because these units have no clutches. When I changed mine in both cars I used Redline with the additive already in it. IMHO Redline is the best money can buy.

Proud2bSS

iTrader: (2)

additive is for limited slip, clutch type differentials (Auburn, Eaton, etc).
Torsen differential is all gears, so no additive needed.

chicane

...But would not recommend RedLine in the differential. I'll run their products everywhere else, but not in the differential. Too thin and doesnt have the shockloading properties required for a daily driver... maybe for a racecar that will see normal lube changes (like every race) but not something I would consider street worthy.

I would be more opt to using TORCO's RGO 85-140 for your use. 80-90wt is a little too thin for performance use.

BTW... there are more than 296 threads that deal specifically with differential fluid.

01Z28M6

Matt, just so you know what's in the owner's manual of a 2000 Firebird, it specifies 75w90 weight Synthetic axle lubricant with 4 ounces of the limited slip axle lubricant additive. GM has these specs because they want to avoid warranty claims. If a heavier lubricant or omitting the additive were in their best interest, they would have different specs.

You can take other advice but at least you know what the manufacturer specifies.

edit: just in case you want a pdf owner's manual for your car.

http://www.marshu.com/images-website...ner-manual.pdf

makxc50099

thanks for the help. i understand that there was prob. tons of threads on it but the searrch function here doesnt work half the time and it was one of those times that it didnt work.
thanks for the help.
ps.
where would i find the 85-140?

chicane

Sorry for the low-tech approach to answer this... but take a look here to find your nearest dealer:

http://www.torcoracingoils.com/Products/dealers.aspx

...And you just reminded me about the search issues. You are right... it doesnt work half the time for me either. But when it does... lol

makxc50099

closest dealer is around an hour from me