Schaeffer Manufacturing Co. 02937590-012 Supreme Gear Lube SAE 75W-90, 1-Quart Bottle (Pack of 12)

Great diff oil. I have my friends and family running this in there diffs too. Checked the oil after 20k miles and the oil still looked clean and new. Running the 75 90 in my 2004 sierra duramax allison. I tow up to 12000 lbs all summer long and its holding up great. Gm recommends 75 90 in the diffs.

I use this in the front and rear differentials and in the transfer case of my '88 Toyota Land Cruiser. I had neglected to service them for several years (my own fault, but I had an ugly divorce and very nasty custody battle I was fighting for several years), and when I finally did, the dino oil I drained out was BLACK and thick. Luckily no metal shavings, excessive noise or noticeable vibration though. I serviced them with the Shaeffer's, drove a few hundred miles, then drained and serviced again. The oil came out dark again from absorbing all the nastiness built up in there, but the most recent fill is still clean, telling me that all the old gunk is gone now. I've noticed that my drivetrain has gotten much smoother, especially when in 4WD. Like I said before, it wasn't noisy enough to lead me to think there was a problem, but the Schaeffer's really helped it smooth out. I also use their All-Trans in my Land Cruiser's transmission with great results. Runs much cooler and shifts nice and crisp. I'll be using their GL-4 rated gear oil in the 5-spd when I have it swapped into my rig in the spring as well.

What can you say, it's Schaeffer's. Absolutely top notch fluids. However, I would say that adding volume measurements on the side of the bottle would be a nice improvement to be a little more precise with adding non-whole quantities. Not worth removing a star for, but for the price I would expect that.

Used this oil twice in the front diff in my AWD Denali. Works good, I filled it up with this stuff originally in early 2016. I noticed about 6 months ago my diff is getting whiny at in the upper RPM's, so I drained it a week or so ago with the same stuff and its quiet again. Not gunna complain about the longevity due to me being AWD, I drive hard, have put upwards of 30,000 miles between intervals and my Denali is getting up there in milage. Next time, I plan to use Redline Heavy Shockproof just to experiment, but if it doesn't blow me away, I will quickly come back to Schaeffer's.

This product was used and recommended by the manufacturer of my trailer for use in my oil bathed bearings. It is a synthetic oil and can withstand high heat environments.Once ordered, it arrived within the 2 day prime schedule as promised. I am very pleased with this product and would purchase it again as needed.

Schaeffer’s is the best oil I’ve found I run it in everything that accepts oil in my truckEngine trans T case and front and rear endIt works great!

I am giving the product 5 stars but giving the price -1 because it increased from $13.58 to $19.90 that's more than $6.00 or 32% in a few days.WOW! I bought 2 quarts on 8-9-2017 but need another to finish the job so I will have to pay the current 8-12-2017 price. The average price I paid was $15.68 per quart, better than what is now but still.... This is really good lube but I will be getting Mobil One from now on because I will not have to wait, it is found every where, and cost less for the same weight of oil.

Excellent smoothness after replacing rear diff, make sure you have a pump to fill! Going to try their 5w-20 Supreme 9000 after great success using the gear lube.