Thread: Redline Heavy Shockproof 75W90?

I have used Redline MT-90 in my non-LSD Nx2000 and it really does protect the gears when slightly misclutching and it also reduces drive train losses.

But after reading here and there, I read on the Redline website that their Heavy Shockproof behaves like 75W90 and from their bulletin also that this product is only recommended for application with cars that do not carry factory warranty anymore.

I wonder, should I stick with MT-90 or would I with my delivery style DD benefit more from Heavy Shockproof?

Any good reason to not use Heavy Shockproof?

Found one

"Not recommended for most synchro applications due to the product's extreme slipperiness"

Red Line Synthetic Oil - ShockProof® Gear Oils - Heavy ShockProof®

i tried the heavy in my spec V trans and it wouldn't shift lol.

Yah a lot of us turbo guys use it. I didn't like it because it is very "thick" feeling until warmed up yet the first shifts in the morning can grind because even though it feels thick, it is extremely slippery which doesn't let syncros work properly.
Otherwise it is fine, but that was too much annoyance for me, so I've gone to a 50/50 mix, and even that is not good, so I'm going back to straight MT-90 when I can. For a racecar it is fine, but for daily it is something to seriously consider before using. Your second gear dog teeth will last much longer if dailying on MT-90.

Redline makes a product called "Shockproof Light", it was formulated for syncrod trannies in exteme conditions. This is what I told and is now what I use relegiously.
The way the heavey shockproof was explaind to me was that it has very similar charactoristic as syncromesh, it softens the brass of the syncros, and in heavy shockproof it does it so much that it causes them to wear at an extreme rate, as it was formulated for a cog/dog style gear box that needs the slickness and protection that is involved with them.

As for it gettting "thinner" as it warms up is a correct statement, but it does not lower the viscosity of the oil. Most people think that when it thins out the vescosity changes, because this is how standard non sythetic oils work. The numbers 75 90 is just for referance to make it more of an industry standard. Redline 75 90 is a 90 weight oil, constantly.

Mabe other that read this post will now have a better idea of what redline oil is all about.
BTW mt90 is a great product also, if it works for you and you like it I wouldn't change.
Just my 2 cents

I've always suspected Lightweight Shockproof to have the same frictional problems (too slippery) that Heavy Shockproof has. This is based off their descriptions of each fluid on their website. They describe their frictional properties identically.

I have ran it in my AE86, GSX, TSi, GSR, and have seen it used in hundreds of supras that I have worked on. It is completely overkill for the street, no doubts there. MT90 is deffinately the best street fluid to use, and its a lot cheeper. I used to be able to get the SPL for the same price as MT90's retail, so I went that route.

Now, with what you have seen on their site, I can conclude this, that heavey has an aditive that attacks brass syncros and lightweight does not, and from what you have said with it being too slick may be correct as I have not heard anything to comferm or deny that statement. I have not seen or experianced any ill simptoms in my other vehicals, that doesn't mean that it is perferd in an SR tranny, again if mt90 works stick with it, its a fantastic product and I doubt anyone has anything bad to say about it other than the price.

This is what confuses me.

"Film thickness greater than an SAE 75W250, yet low fluid friction like 75W90"

Red Line Synthetic Oil - ShockProof® Gear Oils

I call that a sale pitch which doesn't compute with the quote I made before in this topic.

But I'm convinced that me just order MT-90. I know it performs really well, not worth the trouble 'to just try it'

But Redline could be more clear on this I suppose.

Thick fluids can have low friction. What's hard to believe?

It is implying it behaves like 75W90 on one page and then later on it is not a 75W90, that is what confuses me.

I would happily pay a little more to Redline but I'll stick with the MT-90. Seems like that is my best option. I'll try some 5W30 too next oil change (first on the GA16)

Besides I'm poking in the dark here, I have to import Redline products and I know only one other person over here using this and he has no opinion on MT-90 would squeeze more life and a little more HP on the wheels with this stuff.

But you can hear it with a slight miss at shifting.