Dumb question on gear oil... (1 Viewer)

[chrisbruck]

It's time for me replace the gear oil front and rear along with the transfer case. I'm in the South so SAE90 should be fine temp wise for me. I just realized the transfer case specs 75W-90, all per the owners manual.

Is there any problem just using the same gear oil for all three?

 

[AimCOtaco]

Works for me, simple is good and its easier to carry extra along when it's all the same type.

 

[aging fleet]

I just did my diffs and transfer case over the weekend and used M1 75w-90 in all three. That's the weight I used for the previous fill also.

In case it's your first time doing this, it's really helpful to have a few feet of clear plastic tubing on hand. That way you can gravity fill the front diff instead of using a pump, comes in handy for the transfer case too. If you lower the spare, you should be able to fill the rear diff directly from the bottle. I used a hand pump my first time around and made a hell of a mess.

 

[geanes]

For those with LXs, they have the Limited Slip rear. For my LX, I put the Mobil1 Synthetic 75w/90 LS in all 3. If you have an LC, you won't have to worry about getting the LS gear oil.

@AimCOtaco is correct in that it's much easier to just carry one type of extra gear oil. That's precisely why I put the LS oil in all 3 diffs vs LS in the rear and standard in the TC and Front Diff.

 

[chrisbruck]

I've changed before, just never noted the different rating on the TC. Used the same in all three before. Just was curious if there was a reason for something else in TC. Mine works fine, whines a little when really cold, but no big deal to me.

 

[FLWookie]

All LX years or is this a specific range? I have an 00 and wasn't aware it had a limited slip rear.

 

[geanes]

All LX years or is this a specific range? I have an 00 and wasn't aware it had a limited slip rear.

98 and 99 only I believe. ATRAC eliminated the Limited Slip to my understanding.

 

[bls72bmw]

Great thread, will do mine soon.

How much will I need for a 98 LC100?

Def going to use all same 75/90wt

Thanks fellas!

 

[geanes]

Great thread, will do mine soon.

How much will I need for a 98 LC100?

Def going to use all same 75/90wt

Thanks fellas!

Differential, with Locking diff Rear..........6.8 pints
Differential, witho Locking diff Rear..........7.0 pints
Differential, Front..........3.6 pints
Transfer Case,..........2.7 pints

 

[bls72bmw]

WOW!
That's a lot O Fluid...

 

[aging fleet]

Differential, with Locking diff Rear..........6.8 pints
Differential, witho Locking diff Rear..........7.0 pints
Differential, Front..........3.6 pints
Transfer Case,..........2.7 pints

Pints! You're making my brain hurt.

 

[geanes]

Pints! You're making my brain hurt.

Sorry. Most of my volume measurements are done in beer.

Here they are converted....

Differential, with Locking diff Rear..........3.4 quarts
Differential, witho Locking diff Rear..........3.5 quarts
Differential, Front..........1.8 quarts
Transfer Case,..........1.35 quarts

 

[Tareq]

For those with LXs, they have the Limited Slip rear. For my LX, I put the Mobil1 Synthetic 75w/90 LS in all 3. If you have an LC, you won't have to worry about getting the LS gear oil.

@AimCOtaco is correct in that it's much easier to just carry one type of extra gear oil. That's precisely why I put the LS oil in all 3 diffs vs LS in the rear and standard in the TC and Front Diff.

Just did this yesterday while taking AHC out and installing Ironman Profoam.

Mobil 1 from Amazon is about $10

 

[Tareq]

WOW!
That's a lot O Fluid...

All 3 take 6.5L so buy 7 x 1L bottle

 

[MyLandy]

I was told to get 8 quarts to do front and rear diffs for an '06. Were they thinking I had solid axle front and rear? My shop just changed front and rear diffs and only used somewhere between 5.75 and 6.5 quarts judging by how much fluid is left, which would line up closer to the quantities noted above.

 

[geanes]

I was told to get 8 quarts to do front and rear diffs for an '06. Were they thinking I had solid axle front and rear? My shop just changed front and rear diffs and only used somewhere between 5.75 and 6.5 quarts judging by how much fluid is left, which would line up closer to the quantities noted above.

Typically, 1.8 quarts for the front and 3.5 quarts for the rear. Generally need to "top-off" the rear after a few days as the diff oil moves out into the axle housing. Having said that, when I did my 98 LX, my front took 2.4 quarts and rear tool 4 quarts. I fill on level ground and go until the oil barely seeps out of the fill hole. Curious why they didn't do the transfer case at the same time. I do all 3 at the same time, 60k intervals using 75w90 Mobil1 Synthetic LS fluid.

 

[MyLandy]

OK, thanks for that. They didn't do the transfer case because I didn't ask them too, that's a great point though and I will make sure to do that next time. And possibly needing to top off the rear after a few days gives me a great excuse to check the levels just in case.