The Royal purple Max Gear 75W140, say on the label it had friction additives.

All viscosities of Max-GearŪ are formulated with hypoid friction modifiers necessary for use in clutch or cone type differentials. No additional additives are necessary.

Anyone running this and any problems?

I did a search and seems only a few are using this, most use Mobil, or AMsoil.

You should have no problems running it.

I have used the Mx Gear 75W90 since the first change ,gone 30,000 miles without a problem. If you study the specs, you'll find Royal Purple has as good or better numbers than any of the other synthetics.

I put 75w140 in my rear end, and I think it's too thick. The gov-loc seems to be a bit lazy now. I don't know if the oil viscosity has anything to do with it, but I know there are some fly weights inside that could probaly be affected.
I personally would stick with 75w90.

John

I've run RP 75-140 for a long time and my locker works great. JMHO

i like a little thicker oil like the 75-140 thick is good in the diffs

I changes all fluids, Front Rear, and transfer case. Here's the thing that just grinds me. When I went to transfer all the fluids I drained from the rear, front, and transfer case it just filled up a gallon jug. I knew GM was short on fluids ( as my 04 was) but this is ridiculous.
I put the 75-140 in and took it on a test run to the same plcase where the limitd slip would kick in and it kicked in at the same place as the OEM stuff.
Man was that stuff bad that came out, with only 5k miles on it.
The magnet was loaded on the plug from the rear end - and it also had a pretty good chunk on metal on it. Not a fragment or the metal dust, but a full on chunk of metal. Scary.

that chunk might not be good could you tell look for where it came from was it the ring pinion or the spider gear and i would think that the front rear and transfer case would hold alot more than a gallon how much did you use to fill them all up again

I tryed looking for the chunk in the driveway to take a picture of it. Seemed to me one side was polised, while the pther dide was cast metal, sorta 1/4 round about the size of a kids ring? mAybe 1/2 the sizze of a persons small finger nail?
I put in 4qts rear, 2qts, Transfer, and 2 qts front, plus or minus maybe a 1/2 quart for spills, and leftovers in the bottom of bottles.

the t-case only took 2qts i think mine took more but i could be wrong anyone esle knoww how much it took them to fill the t-case

I've run the Royal Purple 75-140w in all of my trucks (Fords and Chevys) for a quite a while now with no bad effects. These trucks all see plowing on a regular basis, which I figure is harder on the rear end than just running down the road. I generally change the fluid in the spring and just before winter no matter what the milage.

i've run royal purples products in all my trucks and atv's and have had no problems. 75-140 front and rear and there atf in the trans and transfercase

Is you can see in my signature I have a 03' and my t-case takes 2qts of atf, rear end 4qts, and front 2qts. I used 75-90 redline fluids in my axels

royal purple is the best gear oil that i have ever used i put it in my 69 GMC and i have front and rear lockers and i have never had any problem with them at all