I'm getting ready to do the Front and Read Diffs and Transfer Case on my 2002 and want to use the Mobil 1 75W-90 LS gear lube. Question is that the product is called LS for limited slip, but should I add an additional tube of the limited slip stuff for the Rear Diff anyway?

Thanks in advance,
RH01

see if it chatters without it. do tight donuts both ways after you change it. i've had good luck with royal purple in the rear without adding the modifier.

Does it matter to use synthetic or regular gear oil to the differential? And what weight? I have a standard Differential.

I have the M1 LS fluid in my rear diff and did not add any additional friction modifier in it and have been having no problems in my LSD 04 rear differential.

Alright, sounds like I'll do the try it and see method! Thanks for the input, guys. When I get it done I'll try and get the results on here.

RH01

Sounds like you have decided.

My .02 cents: Use correct weight synthetic and add limited slip friction modifiers. It does not hurt it and extends the life of your differential.

I have the M1 LS fluid in my rear diff and did not add any additional friction modifier in it and have been having no problems in my LSD 04 rear differential.

Same here. I used it for the first time last summer in my rear diff. Didn't add any friction modifier and have no unusual noises.

i am going with Lucas Syn 75w/140 when i change mine next week. My wallet will not come out of my pocket when i pick up the bottle of royal purple. Lucas has the additives in it already and it is for hypoid gears. Everything my manual says use is in the Lucas.

Same here. I used it for the first time last summer in my rear diff. Didn't add any friction modifier and have no unusual noises.

To add, when I had gotten in some dirt and from a stop, when I stepped on the gas, the rear-end came out and I left 2 spin-marks so I know my LSD is still working with 107,800 miles on it.

I have 2 large tubes of friction modifier that I may use if I ever get my hands on some some regular gear oil as I have no problem going back and forth, using whatever I can get my hands on.