Okay... so I have started to hear some grinding in my transmission at the start third gear and sometimes in fifth if I am pushing the car hard. As such, I decided maybe it might be time to switch to a good synthetic brand of gear oil.

I searched and got quite a few good ideas. I got the consensus that the Redline MT-90 is the oil of choice for lightly grinding gears, clashing, and so on. However, I also read some posts about the "Shockproof" Redline gear oil. I went to Redline's site and it says for the description that it is for heavily loaded or transmission that see shock loading.

Correct me if I am wrong, but since I have a unsprung 6-puck clutch, would not the "Shockproof" be better to use in the transmission than MT-90? Or should it just be used in the differential alone and MT-90 in the transmission?

If you have used the "Shockproof" oil or have an informed opinion for or against it in the transmission, please post.

 

I have been using super lightweight shock proof for about a year now, in all my car's rear ends as well as have put in a couple of FC manual trannys.

The super light shock proof is about a 75W90 that flows like ATF.

I can without and regrets say that super lightweight shock proof is the best choice for any FC in both the rear end and the tranny. I swear it is worth a couple HP back from driveline losses as well.