Rear diff. fluid

[66mgb]

I know some of you rave about Redline, Mobil 1 and other products - What fluid should I use in the rear diff. of my '92.

Thanks,d

[elwesso]

Redline is the best, but M1 is the choice for many due to its geographic convenience.....

[Q45tech]

In theory the oem fill was designed to last thru the warranty period [70k].

After the tireroad interface, comes the TC, then the rear diff in decreasing frictional losses.

The diff has the greatest friction starting up from a stop [say zero to 15 mph] cold.

Just like engine oil you must select a low temp and a high temp viscosity based on operating conditions.............local temperature and how long your trips are.

OR just assume the factory specs are fine and change the diff lubricant every year to minimize wear..................smeel new lub and smell degraded used lube [doesn't apply as much to fully synthetics...little smell change].

[maxnix]

I use Royal Purple 75W-140 for Texas summer heat.