Differential Fluid Change for Y33

[my12by60]

I have a quart of Castrol 75w-90 on hand (linked below). The limited slip additive is part of the formulation. I read here that I need a bit over 3 pints to refill. So I would need another bottle. Is the limited slip correct for the Y33 rear end? Is the 75w-90 good for a hot climate such as Phoenix?

http://www.oreillyauto.com/site/c/detai ... &ppt=C1985

[94Q45Beast]

I used valvoline full synthetic LSD 75w-90 gl-5, 2 quarts, you should have some left over

[my12by60]

Ok. Thanks. I am on the right track.

[J30tChumpCar]

Limited slip additive will not help nor hurt as it is not needed, our "posi" is a hermetically sealed viscous coupling that does not rely on the gear lube to control traction.

[my12by60]

Got this diff fluid change completed, but I had a heck of a time breaking loose the drain bolt which had not been touched since the year 2000 when the car was manufactured. I could not get full leverage laying under the car on jack stands. I also only had a breaker bar with the 1/2 socket end. I think a 13mm female square head socket would be the perfect fit for the bolt and I was afraid to ruin the bolt by slipping off with my breaker bar. The shift manager at the local Jiffy Lube was nice enough to let me drive in so he could crack the bolt loose from under the car with a big breaker bar while he was standing. No charge. The fill bolt was much easier. So for as much of a bad rap as Jiffy Lubes get, here is one that is staffed with some nice folks. I checked the cost of the rear diff service while I was at the Jiffy Lube -- $108. That is pretty stiff when the 2 quarts of fluid cost me about $20.

[szh]

One thing I always recommend is to check that you can open the fill bolt first. To make sure that it opens easily when you are ready!

Otherwise, you could open the drain bolt, remove the gear oil and ... then ... if you have any difficulty getting the fill bolt to open, you can't drive it anywhere to get it taken care of! Eek.

BTW, if your differential had not been changed since 2000, I am curious to see what you saw after all these years. I try to change mine just about every 30k miles ...

Z

[szh]

Also, FWIW, I use Mobil 1 Synthetic Gear Oil 75W-90 when I get it changed ... but this is not a critical issue, I suspect. Mobil 1 also have a 75W-140, but I don't know if that is worth finding ... the car specs don't seem to require that wide a range.

[my12by60]

The fluid that came out after 15 years and 100K miles was a dark brown as opposed to the light amber color fluid that I put back in for the refill. I did not notice any particles in the outgoing fluid nor did it smell burnt. And yes, good advice on making sure the fill bolt will open before the fluid comes out of the drain bolt.