Red Line57904 75W90 GL-5 Synthetic Gear Oil for Hypoid Limited Slip Differentials - 1 Quart (2 Pack)

The rear diff on my '07 Tacoma Sport was so rough I thought it was toast. I changed the oil with this Redline 75W90 GL-5 and it works sooo much smoother. I'm guessing the previous owners filled the diff with regular gear oil without any limited slip additive. With this Redline gear oil it runs smooth as silk... like I have a new diff! No special additives needed. I'm so happy I went with this product.I bought 4 quarts and used just over 3 to fill it. The only issue I had was the bottle opening is not a standard size... slightly smaller than a normal quart opening. It will work with quart hand pumps (SP) though, just be careful to hold the pump in place on the bottle and not spill any.I plan on using this same oil in the transfer case and front diff as well. You will need a 6$ crush washer kit for all the drain/fill plugs. Includes both diffs & T-case.

Great stuff!

I emailed Red Line to see what they recommend for our 2009 Harley Davidson Sportster XL1200 since it has the primary and transmission sharing the same case. They replied their 75w90 is what customers use and they recommend with great results. I took the bike for a spin to heat up the oil and did the drain and let it sit for some time to try and get as much out as possible. When I was ready to dump in the quart of red line hold cow it was a punch to the nostrils, this stuff smells terrible even when new. It took about 6 weeks and a couple hundred miles of riding to get the smell down to where it was as noticeable or stinking up the garage. Small price to pay, Red Line is one of the best lubricant manufacturers out there I have been using their products since 1992 in my cars and never had a oil related failure to date. The Harley shifts great and is easier to find neutral versus whatever fluid was in the bike from the previous owner.

This is my favorite synthetic gear oil to be used in a wide variety of applications for Front and Rear Differentials. I tend to replace my gear oil every 50,000 to 60,000 miles .I replaced it most recently in my front and rear differentials on my 2011 Subaru Outback at 120K miles. In most cases it’s fairly straightforward, but you’ll need to look up your particular vehicle’s drain plugs, fill plugs and check fill plugs to make sure you have the right tools. For Subaru, they use some asinine 13mm square plug for the rear differential, and in the front there’s a T70 torx required which is not usually in most kits. So half the battle sometimes is finding the right adapter at a pretty substantial cost. The other half is a mixture of finding the appropriate fill quantities and doing the actual work.Keep in mind that in removing plugs, to always remove the fill plug first. If you are take out the drain plug first and realize the higher fill plug is seized or you end up stripping it, then you’re out of luck and will need a flat bed tow to move your car.Have used this fluid on countless other cars as well and would encourage investing a few extra dollars on RedLine vs some of the cheaper synthetic alternatives (Mobil 1 comes to mind).Always good to have some extra on hand as well. If your car is equipped with a dipstick, you can also examine and compare the color to the fresh fluid.

If you are aren't familiar with Red Line automotive lubricant products -- be informed that most knowledgeable mechanics consider it to be the best line of petroleum products available. My cars are all currently FWD, but I have a long history of ownership and maintenance on 4-speed manual transmissions and RWD differential units. Presently, I use this gear oil in the differential of my Yamaha shaft drive motorcycle. My recent experience . . .The original Yamaha factory gear oil had been changed to Valvoline Synthetic at a few thousand miles. At about 16,000 miles on the odometer, I had noticed a little bit of audible gear while decreasing speed down to a stop. I figured it was time for a gear oil change and this time installed the Red Line 75W90 Synthetic Gear Oil. The whine immediately disappeared. Would it have disappeared if I had used any other oil? Probably. Or maybe not. Either way, I really like knowing I have the best lubricant available in the gear unit.I'll should also mention. This stuff is super slick, and claims to reduce heat dramatically and increase efficiency (gas mileage) a few percent (we'll see). It's so slick that the manufacturer suggests that for limited slip applications, a limited-slip additive is probably not needed to eliminate chatter (I recall in years installing a rebuilt Chrysler 8 3/4 posi unit and had to do exactly that -- put in an additive to prevent chatter -- so Redline is claiming I possibly wouldn't have had to do that using their lube -- an interesting claim).UPDATE: After putting about 6,00 miles on this Redline in the differential (motorcycle), I've "touch-tested" regularly, and can report with confidence that this stuff absolutely reduces operating temps. A lot. Even after extended high speed/summer temperature use, the differential temp never got much past "warm to the touch". With the original Yamaha gear oil, it got HOT. This is great stuff.

I recently bought a Saturn sky redline and did a rear differential fluid change. I'm not sure if this is placebo or not, but it seemingly drastically improved my overall ride quality. My power delivery seems more linear, car seems to ride in corners better, and improved responsiveness slightly. I could be going crazy but the car seems more fun to drive now!

perfect

Red Line chemicals are expensive but they are specifically engineered for specific applications. These fluids actually produce a difference you can feel and hear. Those that know choose Red Line.