redline shockproofing oil then the other 4 quarts of the mt-90? do they mix? does it actually help when beating on the transmission a little?

 

I have heard it works fairly well, but I've never tried it. I have used 100% lightweight shockproof in my RX-7 for about 10k miles and it wasn't much different than a GL-5. Redline says it's not recommended for synchromesh transmissions. I would not try it, unless my tranny already has bad synchros and I will be throwing the whole thing away when it shatters.

Shockproof is a very high EP oil with suspended solids, which means it is designed for situations where gear contact pressures are at an absolute maximum. If you've stripped the gears in your tranny under load or have seen your gear teeth pit or spall, then you might want to consider using 100% Lightweight Shockproof. But your shifting will suffer since the synchros won't be able to grab and synchronize the gears as smoothly. Your synchros will then wear and lose their effectiveness faster, and wear the dog teeth of the gears too. How much faster, I can't say, but you can feel the extra clunkiness in the shifter.

If you're more concerned with the shifting aspect, definitely stay with the MT-90. The performance of the synchros really depends on the friction characteristics of the oil, and MT-90 is ideal for our trannys while having really, really good torque capacity and wear protection. I think very few people fall outside of this category.

BTW, Redline Lightweight Shockproof has the color of yellowish dog puke and smells even worse

Dave

 

Awesome, gotta try this