🔴 Red Line Limited Slip Friction Modifier - 4 oz. (Part # 80301) Review

This material is a necessary evil when you have limited slip. Once installed, the advantage was obvious. However, I would design the outlet differently. The easiest way to install differential fluids is to use a rubber hose and just tip the bottle at the end. The spout of this bottle does not allow you to attach a rubber hose. I had to squirt it in the hole and it was a mess. I think the alternative would be to mix it with the diff oil before pouring it in the diff, but my diff was already…

I love, trust and use Redline oil in my vehicles. When my limited slip differential started to rattle, which happened every time after a fluid change with Redline 75w90 GL5 gear oil, which is suitable for LS differentials, I usually add two extra bottles of this limited slip friction modifier to eliminate vibration . Most other brands of limited slip friction modifiers come in tubes that fit into the differential's fill hole. This Redline comes in a bulky bottle that's guaranteed to spill half…

My 2011 M3 started making a little noise after I changed the factory diff fluid to Castrol Syntax with no friction modifier. About a month later, the noise got a little louder. I added about 0.5-0.75 ounces of this liquid and the noise was gone by the next run. Due to the fact that you don't need much of this liquid, I wasn't entirely surprised when I saw someone poke a very small hole in the plastic o-ring and suck out some of the liquid before I got it. I suppose I should have done that with…