Rear Diff fluid. . .

Quihyp · Post by **Quihyp** » Sun Mar 30, 2014 8:39 am

I just returned from Pep boys and they gave me 2 quarts of 75w140. From reading the forums here I should have gotten 80w90 and they messed up? Is a high-viscosity synthetic better for a high-mileage (180k-ish) engine?

LiftedAWDAstro · Post by **LiftedAWDAstro** » Sun Mar 30, 2014 10:44 am

80W-90 is all you need for the rear diff.

For the engine though, it's a little too thick!

As long as your oil pressure is good, run either 5W-30 or 10W-30. No need to run synthetic unless you can buy it on sale cheaper than dino oil. I find that the case at NAPA sometimes.

Quihyp · Post by **Quihyp** » Sun Mar 30, 2014 10:47 am

LiftedAWDAstro wrote:80W-90 is all you need for the rear diff.

For the engine though, it's a little too thick! As long as your oil pressure is good, run either 5W-30 or 10W-30. No need to run synthetic unless you can buy it on sale cheaper than dino oil. I find that the case at NAPA sometimes.

It was like 15/bottle and I'm primarily concerned with the longevity of my differential. I'm not sure it's been changed possibly ever, honestly. is the 75-140 going to hurt it? Should I exchange it for some 80w90?

Chevy & GMC Vans

Chevy & GMC Vans

Rear Diff fluid. . .

Rear Diff fluid. . .

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Re: Rear Diff fluid. . .