Hey guys I'm about to do the tranny fluid change this week and I'm throwing in the red line mt85 but was considering a gear oil additive? It's slips on 2nd and 3rd at high rpms.

 

Is it slipping out of gear or is the clutch slipping? Big difference. Gear oil additive won't do anything if it's a clutch issue. In addition, most oil makers say not to use aftermarket additives with their products. Lubricants are chemical compounds formulated for certain performance characteristics. When you enter an unknown additive into the mix, it will disrupt the balance intended by the oil manufacturer.

 

Gear additives are pretty much going to mask a small problem in the gearbox, thats how I see it. Although there's nothing wrong with adding additives, just be weary of what you put.

Personally, I used some Nulon G70 on my previous car as the gear changes were a tad notchy only when cold. The gearbox was really tight tho, so it was in real great condition. The G70 stuff was real good. I knew many friends who used the stuff in their cars(same car as mine), and they all raved about it.

At the end of the day, it will only do so much. Like TalkingHorse said, if your clutch is slipping, well thats another story.