Royal Purple Gear Lube

[Disturbed One]

I just had my rear end redone with 3.73's in it. Got it back from the shop ready to put into my car. I bought some 75w-90 Royal Purple Gear lube from my local guy. Is 75w-90 going to be ok for break in and DD use??? Use that for break in then switch to a heavier lube?? I'm wanting to make sure I get this done properly so I don't end up

I may take it to the track once a month if I'm lucky at all. The only other gear Royal purple gear lube he carrys on hand is the 85w-140.

 

[sgarlic]

That'll be fine, but if you're really concerned I'd drain and refill it again in 1000 miles or so with 75w140. It used to be 75w90 anyway but changed sometime in 00 or 01 if I recall, so it's obviously fine since it's the same rear end.

 

[goshia]

The MaxGear 75W90 will work fine in your differential - it just does not meet the factory recommended viscosity grade.
MaxGear 75W90 is used in racing and high performance applications and has plenty of load carrying ability and protection for your Mustang.

Oils vary in fluid thickness by temperature. They thicken at low temperatures and get thinner as temperature increases.
This is measured by a term called centistokes (cSt).

Look at the link below for details
http://www.weather-check.com/royal_purple.htm

 

[Stang2003GT]

I feel better with 75w140. Safe.

 

[four six]

the royal purple shoud be ok. but don't quote me on that