Mobil 1 gear oil ok in Diff. & Trans????

[GTS02]

I tried the search files, I have a gift load of Mobil 1 gear oil 75-140 Super-Syn. Is it ok to put it in the differential with the Mopar lock-up additive. Also is this oil ok for the Trans.

 

[Qualitywires.com]

I can't remember why...but you do not want to use it in the diff. Keep with Mopar.

 

[ViperJohn]

Stick with the Mopar fluids, they are expensive but specifically formulated for the Viper. The differential fluid is as thick as molasses and the tranny fluid is also quite thick to help reduce gear lash. I am not sure what year car you have, but if you have a 708 cam car, the gear lash will be horrific at idle.

 

[Chuck 98 RT/10]

Rear fluid and tranny fluid are completely different. Rear is thick as molasses, tranny is water by comparison.

As for the quality of Mobil1. I use the motor oil in my motor. I'm not sure about the gear oil but it will probably do the job in the rear.

 

[Tom F&L GoR]

Please don't put gear oil in a transmission. I can't comment on ab's review, but in general, gear oils have aggressive surface active additives to provide the wear protection under the severe load and sliding of hypoid differential gears. These additives can be so aggressive that they corrode yellow metals (brass, bronze synchros, bearings) in a transmission. While I don't think there are bronze synchros, I do think the T56 has yellow metal bearings.

Gear oils also have friction modifiers that may interfere with synchro action. Too much of a "good" FM will make it harder to shift, since the synchro ring will take longer to come to the same speed as the gear you want to engage.

Some oils are rated both GL-4 or GL-5 and MT-1 (differential and transmission.) Since the Mobil gear oil is not MT-1, I would stay away from using it in the transmission.

 

[ViperJoe]

GTS02.......since you're fairly new.....for your future reference......

When you see a post or reply that deals with lubricants from Tom.......

Take it as Gospel!