Synthetic Gear Oil

[Maximus Ram]

OK. question. The rear axle on my daughters GC is "whining". I am going to change the gear oil. It has a stock LSD. From what I have been reading, if you use synthetic gear oil,such as redline or royal purple or ??, you do not need to use the LSD additive. Is this true ? just wondering, because I've not heard that before.

 

[ntsqd]

I would pose that question to the mfg of the oil of your choice.
Or just put it in and not worry about it.

 

[Jeep]

Most synthetics already have the friction modifier in the formula. If your GC has the Dana 44 rear with the aluminum center section you may need a little more than on oil change, they were notorious for gear noise.

 

[Maximus Ram]

Unfortunately it has a d35. Checked the diff and low and behold, the PO never checked it(I guess), cold feel any fluid. So went and put some regular gear oil and additive in it to see if the noise goes away. If not, looks like we will be getting a new(used) one from the wreckers. (cross fingers)
This is actually my Daughter GC that she bought with her own money and we are trying to get it road worthy and safe for her.

 

[Jeep]

I have a pile of low mileage/good used Dana 35 stuff, if you need any internal parts like ring and pinion or a carrier let me know and I will see if I have them. You can have them for free, just cover the freight. It's just stuff that is too good to discard and will most likely not get used.