Rear Differential Fluid Change

[jakcol997]

Hey guys! I noticed my rear diff is leaking a drop or two, so I decided to change out my rear diff fluid. My question is, what weight to I need to get? Also, from compline.com it says I have 3.73 with positraction limited slip, and ive read I do and I don’t need the additive.. anyone change their rear diff fluid have any opinions? I need help

 

[wjburken]

Hey guys! I noticed my rear diff is leaking a drop or two, so I decided to change out my rear diff fluid. My question is, what weight to I need to get? Also, from compline.com it says I have 3.73 with positraction limited slip, and ive read I do and I don’t need the additive.. anyone change their rear diff fluid have any opinions? I need help

If I’m not mistaken, that vintage of truck takes 80W-90. Do you have an owners manual?

 

[HiHoeSilver]

I'm guessing that info came from your RPOs? Gt4 and g80, I believe.

Plenty of opinions on the friction modifier. I believe after all of the back amd forth I've read, the AC Delco spec fluid or the Royal Purple have it in the mix already. You're going to hear a few different things about this.

 

[jakcol997]

If I’m not mistaken, that vintage of truck takes 80W-90. Do you have an owners manual?

It doesn’t say how what weight or how much..

 

[jakcol997]

I'm guessing that info came from your RPOs? Gt4 and g80, I believe.

Plenty of opinions on the friction modifier. I believe after all of the back amd forth I've read, the AC Delco spec fluid or the Royal Purple have it in the mix already. You're going to hear a few different things about this.

Yes! I bought the 5 RPO look ups for $5.. can’t look up my 14 RAV4 though! But that’s all steale

I'm guessing that info came from your RPOs? Gt4 and g80, I believe.

Plenty of opinions on the friction modifier. I believe after all of the back amd forth I've read, the AC Delco spec fluid or the Royal Purple have it in the mix already. You're going to hear a few different things about this.

yes, gt4 and g80. The guy at Oreillys told me 75w-140... that seemed off cause I haven’t read ANYONE using that one.

 

[HiHoeSilver]

Yes! I bought the 5 RPO look ups for $5.. can’t look up my 14 RAV4 though! But that’s all steale

yes, gt4 and g80. The guy at Oreillys told me 75w-140... that seemed off cause I haven’t read ANYONE using that one.

Should be in your manual, which you can download if you don't have.

Is it 4wd? The front and rear can be different, too.

 

[jakcol997]

Should be in your manual, which you can download if you don't have.

I found the type! It’s 80w90. But it doesn’t say how much...

 

[George B]

Use a full synthetic 75-90 or 80-90. I had good luck with a finicky G80 using amsoil. Is expensive but you
Don’t change it often enough to be cheap.

Edit: like @HiHoeSilver said. Check your manual or share what truck this is.

 

[HiHoeSilver]

I found the type! It’s 80w90. But it doesn’t say how much...

Again, in the manual. What truck is this?

 

[jakcol997]

Again, in the manual. What truck is this?

It’s a 99 GMC Yukon 4door 4wd