I'm getting ready to change my front and rear diff fluid. Does anyone have any opinions on fluid and/or additives?

I don't plan on doing this again for quite some time so I want to find out what's best for the diffs and lasts longest before I get started.

 

Well, when I changed mine I just used the Supertech wal mart brand 80W90 GL-5. The diffs are pretty stout any 80W90 GL-5 Hypoid gear oil will be sufficient.

I suppose you could go synthetic if you wanted in which case I would use red line. I'm using red line MT-90 in my trans and I like it. Didn't really notice any smoother shifting though but I bet it will last longer.

 

royal purple is my vote, but any full synthetic will last. I also like EXXON/MOBILE full synthetic as a less expensive option..

 

I'd stay away from any Exxon/Mobile products, but that's just my personal preference. Royal Purple is good but expect to pay about $17 a quart for it. Red Line is a little cheaper. My buddy just picked up some Amsoil for the diffs in his Jeep. He swears by the stuff for everything.


http://www.amsoil.com/storefront/agl.aspx

 

I've heard royal purple was supposed to be the best but never knew anyone that actually used it.

I've also heard redline but have no clue what kind of fluid it is or where its supposed to be used.

Can I get some price estimates too? That'd be great.

 

click on the amsoil link above. Next time I change out my diff fluids that's what I'll be using.

Here's the redline, some people use the heavy shockproof, I would probably just go with the 75W90 GL-5 which is for hypoid gears, which is what our trucks use.

http://www.redlineoil.com/Products.aspx?pcid=4

You probably can't go wrong with the shockproof either.

All in all, I am going to try that Amsoil next go around, in about 15-20K miles or so, since I just changed mine last August with the cheap stuff.

 

Thanks for the links pruney!
Another quick question: how many quarts does it take to fill the front and rear?

 

Park it on level ground. Where you put the fluid in tells you when its full.

When oil comes to the bolt hole (the top one, where you put the gear oil), shes full.

If you cant see in there for some reason, stick your finger in the filler hole. oil should almost pour out of that hole if its full.

 

I know how to drain and fill it.

I was just wanting to know how much it took so I'd know how much to buy. Oriellys didn't know how much it's gonna take so that's why I asked here lol.

Thanks though.

 

I think the rear diff is around 2.2 quarts and the front is a little less. I would get a gallon jug and a quart and I bet you'd be good.

 

my bad lol sorry.

I dunno for your truck, but since its a 95 it probably has around the same capacities.

My 86 4runner (same 8" rear diff and 7.5" front diff as yours) takes
2.0 quarts front, 2.5 quarts rear.

These are approximate, I would buy an extra qt to top off

 

yes, definitely is the same capacities.

wasn't sure if your rig was after the cutoff date in 95 when they changed things up, but from your signature the car is a 94 so these are the right capacities for your rig.

 

Amsoil all the way! I don't run anything else in my drive train.

 

Amsoil is gettin a lot of love here. I'll probably go with that.

Another question: what do you guys think about a seafoam treatment for about 50 miles before I change the fluid?

I'm an avid fan of the stuff and used it to clean everything else and have had outstanding results.

Just wondering about your oinions and trying to find out if there are any reasons why I shouldn't ie. Seals leaking afterward.

 

Amsoil's Gear Oil Study: http://www.amsoil.com/lit/g2457.pdf I guess we shouldn't be too surprised Amsoil comes out on top of their own study, but it's an interesting read nonetheless.

I don't think there's a need to run seafoam in the differentials, but I'll be interested to read other opinions.

 

I just switched from redline to Royal Purple in my transmission, transfercase and both front and rear diffs. The truck drives much smoother and I gained about 1 -1.5 miles to the gallon also noticed the transmission shifts much smoother. The Royal Purple cost me 17.99 a quart but in the long run I think it will be worth it considering I should be able to travel twice the distance before having to change it.