rear end fluid change?
#2
I think the general guide line is 25,000 miles. Do rear end at the same time you do the transmission fluid.
A lot of people, myself included, use the Mobile 1 with the gm slip diff additive (if that applies to your set up). I don't think you can go wrong with Royal Purple or Redline either.
A lot of people, myself included, use the Mobile 1 with the gm slip diff additive (if that applies to your set up). I don't think you can go wrong with Royal Purple or Redline either.
#5
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,362
Likes: 0
Received 1,794 Likes
on
1,278 Posts
30K sounds good, maybe more often if you race the car hard or live in a real dusty area.
I always use non-synthetic 80W90 + GM additive. That is what GM recommended for the '98 rear.
In my '00, I used the 75W90 synthetic.
I always use non-synthetic 80W90 + GM additive. That is what GM recommended for the '98 rear.
In my '00, I used the 75W90 synthetic.
#7
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,362
Likes: 0
Received 1,794 Likes
on
1,278 Posts
Originally Posted by jlashley2001ss
what about the 2001's?? Is there better weights to use for certain year cars?
IIRC, for all '99+ rears, the 75W90 synthetic was recommended for the standard limited slip rears. Not sure if the cars with the optional SLP (Firehawk/SS) diff. have a different fluid recommendation or not.
Last edited by RPM WS6; 01-09-2006 at 08:57 PM.
Trending Topics
#8
My 98 was built early in the 98 model year and it has a zexel torsen differential. Quick test of this is that they will spin in opposite directions when in the air. I'm pretty sure that 98+ has zexel torsen's installed.
I'd only add the additive if you suffer from "the rusty nail" effect. It's just some clicking during turns with a zexel-torsen. Some diffs have it, others don't. I have 2 of those differentials, 1 in my 88 as well and have not needed the additive.
I'd only add the additive if you suffer from "the rusty nail" effect. It's just some clicking during turns with a zexel-torsen. Some diffs have it, others don't. I have 2 of those differentials, 1 in my 88 as well and have not needed the additive.
#10
TECH Fanatic
iTrader: (3)
Originally Posted by RPM WS6
I beleive it was only the '98s that GM recommended using the non-synthetic 80W90. These rears apperently had a different limited slip unit (Auburn for '98 vs. Torsen for '99+ I beleive). I'm not a rear diff. expert, but that is the information I've discovered.
IIRC, for all '99+ rears, the 75W90 synthetic was recommended for the standard limited slip rears. Not sure if the cars with the optional SLP (Firehawk/SS) diff. have a different fluid recommendation or not.
IIRC, for all '99+ rears, the 75W90 synthetic was recommended for the standard limited slip rears. Not sure if the cars with the optional SLP (Firehawk/SS) diff. have a different fluid recommendation or not.
#11
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,362
Likes: 0
Received 1,794 Likes
on
1,278 Posts
Originally Posted by SladeX
My 98 was built early in the 98 model year and it has a zexel torsen differential. Quick test of this is that they will spin in opposite directions when in the air. I'm pretty sure that 98+ has zexel torsen's installed.
Originally Posted by luvmeZ28
i thought the auburn diff. was just an option for 98+ fbodies.
I've read before that some '98s received auburn diffs. I haven't tested mine personally, but I just go with what the manual tells me.
#12
TECH Regular
iTrader: (1)
Join Date: Mar 2004
Location: Minnesota
Posts: 428
Likes: 0
Received 0 Likes
on
0 Posts
I would do it every year or 10k. I am hanging on to my stock rear as long as possible. If you change it every year you may catch the bearings going before the whole rear goes.
Good Luck
Good Luck
#14
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,362
Likes: 0
Received 1,794 Likes
on
1,278 Posts
Originally Posted by bad6as
so how would i know for sure if my 98 should get synthetic or standard
I've never had any issues following the GM fluid recommendations for these rears, so I plan to continue following that practice.
#16
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,362
Likes: 0
Received 1,794 Likes
on
1,278 Posts
Originally Posted by bad6as
i just looked in my manuel and it says both v6 and v8 rears take the synthetic 75w90 and add the limited slip addative to the lsd
Mine lists: Rear Axle Lubricant (limited-slip diff), GM part #12345977. That part number has since been updated to #89021669. Both parts are 80W90 non-synthetic lube.