K&W 402508 Trans-X Posi Trac Limited Slip Gear Oil Additive - 7 Fl Oz

Works

I have used this product for many years in 1998 Ford Explorer XLT, V6 engine, auto transmission and does exactly what it is supposed to do in a posi-traction differential which require a limited slip additive. Differentials require service every couple of years (3-5) depending on use and mileage, as the lubricant thickens and becomes black, so its time for rear end service. Once removing the rear end cover proceed to drain and clean, apply a new rear end cover gasket to the cover and seal the differential. I squeeze in a tube of this stuff and fill with 3 quarts of the recommended synthetic gear oil for your car or truck, until the lubricant starts to pour out of the fill hole. I have never had any problems, no leaks, no noises, no shuttering, just a smooth sailing ride with something so simple and easy as part of routine maintenance every few years. Check the differential every year, fill if needed. Happy motoring!

This trans-x limited slip additive works very, very well in place of factory additives/modifiers. I had put this fluid in my 04 Chevy Express 3500 with the big ole 14 bolt rear end, and all the chattering that was going on was taken care of after throwing this stuff in during a fluid change. It's very well priced and seems to work just as well as comparable OEM fluids.

I bought this for a 2020 Ram 1500 classic. The additive seems to work but my rear end still makes an ever so slight noise upon sharp turns when accelerating, and when its cold. Now when I say it makes a noise you have to really listen for it and it only last 1 or 2seconds then its over with. And from what I have read this is a normal occurance for this type limited slip rear end. I dont remember it making the noise before the oil change, but I wasn't listening for it either, and after the oil change I was listening for it. So Im going to say its fine. The noise hasnt got any worse, and doesnt do it regularly.

This oil fixed my whaaaanning rear axel issue on my 2000 Firebird Trans Am with the 3.42 LSD. Yes, I had the GM required additive already mixed in the synthetic gear oil. Never had a problem until one day in SoCal.When my car was driving for a bit and and warmed up, from a dead stop, needing to make any basic right turn (90 degree), (or sharp turns too) The axel would produce a profound, yet awful sound that intensified thru the turn but terminated once all the wheels turning at same speed, driving straight following the turn.I'll do my best to describe my sound, what I'd heard, and as accurate as possible. This was a very specific situation when the sound was emmited. I've read similar but also different stories and this stuff resolved my problem. The noise sounded like a roaring whanning rotational sound that would whirl (or "wind-up" wow wow wow wow sound, intesity and pitch increased with speed) as you proceed thru the turn under acceleration. The noise would not occur with you coast thru turns or not giving her any gas at all. I can compare another sound I've heard to my noise- almost like or similar to a sound when a manual car is going in reverse at high torque/speed or up a hill.Hope this helps everyone. This stuff worked for me. Hell yeah!

I had to replace all of the side gears, spider gears and clutch packs in my 8.8 Ford Trak-Lok. On opening the box I was worried about this products validity, as it did not smell like a rotting half dead cat's peed in the box. The stuff from Ford typically does smell wicked awful. I went ahead and used it to soak the clutch plates ahead of time, and then added the rest of the tube to the gear oil as it went into the differential housing. It seems to work fine, the rearend has not chirped, clunked or barked a tire since.

differential additive no problems

Three stars because it probably will work for some but it didn’t fix the chatter on my F-150. The Motorcraft XL-3 stuff did though.