140,000 miles and I'm sure it's never been changed....So I'm gonna change my rear end fluid today. Which oil should I use ?

Here's the sticker in my glove box


80w90 Limited Slip


80w90


Thanks.

 

I don't see the G80 RPO on your sticker so you should just stick with the standard gear oil, not the one for limited slip diffs.

 

Thanks !

 

Ill comment here just so everyone knows. If you have a G80 you dont need any fancy limited slip fluid. There are no clutch plates in a G80, It requires the same fluid as a normal diff. Hope this helps anyone in the future!

 

Ok, thanks.

So I'm looking for a straight 80w90 gear oil that doesn't say anything about limited slip.(like the old bottle in the last picture)

Went to NAPA and Autozone and all they had was 80w90 "limited slip"

Both These places said oil companies like Valvoline are only making the limited slip kind now a days, because you can use them in both posi and limited slip rear ends.

Anyone have any input on this or know of a good oil i should use ?

 

all you need is 80/90w. you dont need anything else. if you cant find it there at Autozone, then you have to go somewhere else. you have just a standard open diff, but why spend the extra money on fluid used for LS and Posi rearends. just get some straight up 80/90w like you have pictured in the last pic you posted.

BTW, if you have never done a rear end in the past, prepare for quite the stench!!

 

Gotcha....thanks for the clarification.

 

With the rear end I have, would this be a good oil ?





Anyone ever used this before ?

 

That would be fine. The manual calls for either 75W-90 or 80W-90. I've been told that the 80W-90 is better for a warmer climate, and the 75W-90 for colder, but you won't go wrong with either. I live in the frozen wasteland of Canadia and am running 80W-90 cause that's all I could find for a reasonable price. I am not an oil specialist, and the majority of my information comes from people on here, past and present.

 

does it only take one of those bottle to fill it