rear diffy fluid

[v6mOtOrhEAdftOp]

Re: rear diffy fluid

I just used valvoline 75w 140 synthetic I believe in mine. It runs much better

[TheGr8Schlotzky]

Re: rear diffy fluid

Is this something that can be changed in the garage pretty easy? Mine leaks a bit and i'd like to get a new gasket and replace the fluid if i can do it in my driveway..

[josh98bird]

Re: rear diffy fluid

Is this something that can be changed in the garage pretty easy? Mine leaks a bit and i'd like to get a new gasket and replace the fluid if i can do it in my driveway..

pretty simple but you have to pump the fluid into the rearend... go to advance and you should be able to find something. It took me about 30 minutes to replace the gasket/seal and refill... well maybe about 45 minutes.

[kala]

Re: rear diffy fluid

Is this something that can be changed in the garage pretty easy? Mine leaks a bit and i'd like to get a new gasket and replace the fluid if i can do it in my driveway..

Ok since my mechanic just did this last week, maybe I can give you some tips. It seems very easy to do. All you need to do it raise your rear but make sure that it's completely level. Then take all the bolt around it and let the fluid drain into a pan. Scrape the gasket off the rear. Since you have y87, you have AUBURN . So, this is what you need:

1. GM high quality non-synthetic 80W90 hypoid gear oil = 3 bottles (used to be 2 but GM decreased the size of the bottle) I always learn the hard way :(

2. GM friction additive 4 oz This one

3. OEM gasket

Buy all these from the gm dealership. Don't make the mistake that I made. They will give you a clear flexible plastic pipe for free which works fine to fill the diff. Car feels great and it'll extend the life of your lsd as you probably know that Auburns tend to go bad if not serviced right. Good luck



:)

[Camaro Dom]

Re: rear diffy fluid

soooo... getting back to the point. i DO wanna change the fluid then?
the logic being that with tranny's, if you wait too long, the fluid gets gunky around the gears and provides a lubricant, and if you flush it out, you get rid of that lube and the gears will have alot more play in them, which leads to more wear and the damn thing giving out altogether...

[kala]

Re: rear diffy fluid

I have been really glad that I did that fluid change. Now I am thinking about doing the trans fluid(only 20k miles since last change). But this time, i want to buy the fluid from gm dealership. I think it's callled dextron III or something.



:)

[crazygrrrl]

Re: rear diffy fluid

Sorry about reopening this dead thread, but I need some info and couldn't find it anywhere. Please help me.

I have 2001 Firebird v6 with an auto trans, and standard diff (not Zexel torsen lsd).

The service manual recommends synthetic 75W-90 gear lube (GM # 12378261) meeting GM specification 9986115. Of course, the manual doesn't say what the heck spec 9986115 means, so I don't know if I can use other brands.

GM charges $35 to $40 a quart for the rear axle fluid! Other brands like Mobil 1 and Valvoline synthetic 75w-90 cost $9/quart, and Royal Purple Max Gear Synthetic cost $18/quart.

Is there any difference between the brands? They're all synthetic, all 75w-90, so why does GM charge almost 4x as much?

Can I use any of the other brands and not damage my rear axle? Again, it's not a limited slip axle, so it doesn't need those limited slip additives.

Any advice would be appreciated.

Thanks.

[darkflare999]

Re: rear diffy fluid

Well i have a standard diff also....and i just did a fluid change like 2 weeks ago and i went with royal purple and soo far its been excellent!!....also i read on the bottle that the additive is already mixed in with it....s0o royal purple was pretty good to me!

[ssms5411]

Re: rear diffy fluid

I get my Royal purple products off of ebay , usually one seller who gives me breaks on buying like the oil , tranny fluid , gear oil , RP ICE, and power steering fluid. He better give me discounts. LOL I figure I save about $10+ on oil chnages since no tax and his discounts and same goes for the rest of the products, since I'll buy in cases, except on the ICE, gear , and power steering fluid. Its been about 2-3 years now. Also like said RP for the rear end works great , the GM mechanic that did my rebuild actually bought some or brought some from home and used it in mine , I thought that was pretty cool of him, he said he uses nothing but RP in all his vehicles and wouldn't use anything else for his. I had a couple of GM mechanics tell me the same thing, it might be becuase of the AZ heat and the RP protects parts better, I don't know, but so far so good. With RP in about everything.

[Skinny]

Re: rear diffy fluid

To answer your question, crazygrrrl, any name brand synthetic 75W-90 gear oil will meet or exceed GM specs. You will probably even see that written on the label somewhere.

Why does GM charge so much more for theirs? Because they can.

[cam98aro]

Re: rear diffy fluid

To answer your question, crazygrrrl, any name brand synthetic 75W-90 gear oil will meet or exceed GM specs. You will probably even see that written on the label somewhere.

Why does GM charge so much more for theirs? Because they can.

exactly. GM stuff is always overpriced. bought a napa axle bearing (torrington) for $20, the ones from ac delco which are also torrington were like $80

me personally? i wouldnt waste my money on royal purple, i bought mobil1 syn and i thought even that was too expensive. look at all of the cars out there with 200,000 miles on the stock diff fluid. Differentials will have minimal wear if they are installed correctly, and if they arent, it doesnt matter what oil you use, its going to eat itself up.

but then again, this is just my opinion.

[crazygrrrl]

Re: rear diffy fluid

Thanks, guys! I'm glad I don't have to shell out the $$$ for GM-brand axle lube. I think I'm going to try Royal Purple if I can find it at Kragen or Auto Zone. If not, I'll try Mobil 1. Either way, it's going to be synthetic oil. I don't want to have to change it again for another 5 years!

[darkflare999]

Re: rear diffy fluid

i got mine at autozone...last 2 bottles left also lol :banana: