The Dodge Challenger Message Board

Has anybody changed the rear axle oil ?
What type of oil is the right one for a 8-3/4 with the sure-grip ? How many liters / pints ?
And where is this screw to get the oil in and out ?

You need an oil made just for limited slip units.

The filler/level hole is on the passsenger side of the diff. It is the thing with the big square plug. To get the oil out is tricky. You have to pump or suck it out as there is no drain hole!

Of course you could just pull the axles out and remove the diff. The oil would just fall out then. But you would need to replace the gasket in this case.

Not a bad idea to adjust the axle end-play while you are on.

I used a syntheic gear oil. then added a small tube of additive for limited slip gears. I filled it untill it came out the filler hole!! about 2 quarts! do you guys think this is ok? I was thinking about drilling and tapping a 5/16 or a 3/8 hole at the bottom of the diff. and then using some sealer and a setscrew to plug it after the oil drained of course. let me know what you think. thanks

I've done the same Glenn with that additive. Can't tell you how it turned out as I haven't drove many miles since I put the suregrip under my car.

It's a good idea about fitting a plug at the bottom of the diff. Just make sure you don't use a bolt/plug which is to long or else you mess up the internal parts when you drive it. And use some teflon tape to seal it.

The oil in the diff should last years so I don't know if it is worth fitting a drain plug?

I do have a spare trans pan drain plug kit that I could use.

This is the third time I have had my axle apart in the last 10 years anyway so it hardly seems worth fitting a plug in my case at least. But I suppose now is the time if I am going to do it because the axle is in bits at the moment.

Yes Glenn you should fill it until it spills out of the filler hole (with the car level).

What kind of oil (viscosity) have you all taken ?
W90 ?

I believe I've taken W90 of that stinky oil also Jens.

I am using mobil 1 synthetic sae 75w-90. I have heard of gains of 10hp or better when synthetic oil is used in the engine, trans and rear end.

I use and recommend amsoil series 2000 SAE 75w-90. I have found it to be an excellent friction reducing lube helping considerably when it comes to fuel economy. Also tested as an industry leader I use nothing but amsoil. If you are interested in using this lube or any amsoil products e-mail me and I will check my dealer for availability. litt810@bellsouth.net

Hi Dan,
I live in Germany. So shipping oil to here could be a real problem. The best available here is the Mobil 1 and I think I will put this in. Thanks for helping.