Shockproof + Amsoil cocktail in 6-speed gearbox
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Shockproof + Amsoil cocktail in 6-speed gearbox
After enduring a year of notchy 2nd gear shifting in my 6-speed with straight Amsoil MTG 75W-90, I decided to try a 25% Shockproof Lightweight + 75% Amsoil MTG 75W-90 in the gearbox. I wanted to try Shockproof because of its claimed ability to help control stresses on gear teeth, but I actually thought that adding any Shockproof would worse shifts because Shockproof wasn't designed for syncro gearboxes. In the first 100 miles with this cocktail, so far, 2nd gear shifts are smoother.
This should be an interesting thread as time goes on.... GL with it and keep us posted. Normally lots of people (me included) would say "NO DONT DO THAT!!!" to this but hopefully you wont destroy anything.
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Why would it hurt longevity? Shockproof is compatible with brass, and supposedly has better shear properties than other gear oils. Redline doesn't officially recommend it because they say Shockproof may decrease syncro performance. If I'm seeing improved syncro performance, then its all good. I'm just wondering if the improved syncro performance I'm seeing now will last.
Well just a thought. Remember when everybody thought Syncromesh was the best their was because it shifted so smooth. Then all of a sudden everybodies tranny started failing with it because they found out it was too thin. I would reccomend mixing a small amount of that coctail together and make sure all the fluid stays mixed together and doesn't separate. I have heard some Redline does not mix well with other fluids. If it works though have at it...I dont have the ***** to take a chance though 
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I'm surprised that anyone runs Syncromech in their gearbox. Its basically 30 wt oil. I wouldn't put it in the 5-speed either. The 5-speed just happens to be strong enough to withstand it.
Where do you hear that Redline oils do not mix well? The WRX community has been using using mixtures of gear oils for years. Both oils are synthetics with bases that are fully compatible with each other.
Where do you hear that Redline oils do not mix well? The WRX community has been using using mixtures of gear oils for years. Both oils are synthetics with bases that are fully compatible with each other.
Actually thats what I was referring too was a thread I read over at Nasioc...(I frequent over there just to see what the competition is up to 
) But it was about using a non syntethic gear oil with I believe their shockproof or some other fluid. I dont think you will have the problem since you are using both synthetic gear oil. I believe it was a very rare occasion but just thought I would throw it out to make sure you know to test just for piece of mind if you wanted. One other thing to note is if you look at Amsoil, Motul, and the Castrol which seem to be the most popular three all the cold flow properties of the oil are good but they are optimized for high shear point and high temperature therefore making them shift somewhat stiff in the cold...which in some ways means its a good oil. Motul of all seems to have the best cold flowing properties and shear points (I am trying this on Thursday). GL with the coctail though.
) But it was about using a non syntethic gear oil with I believe their shockproof or some other fluid. I dont think you will have the problem since you are using both synthetic gear oil. I believe it was a very rare occasion but just thought I would throw it out to make sure you know to test just for piece of mind if you wanted. One other thing to note is if you look at Amsoil, Motul, and the Castrol which seem to be the most popular three all the cold flow properties of the oil are good but they are optimized for high shear point and high temperature therefore making them shift somewhat stiff in the cold...which in some ways means its a good oil. Motul of all seems to have the best cold flowing properties and shear points (I am trying this on Thursday). GL with the coctail though.
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Nice 
I have been using almost 1qt redline shockproof Heavy and the rest Redline MT-90 in my 6spd ever since my rebuild. Has never shifted better and my tranny temps went down a tad. 12k miles so far.
I have been using almost 1qt redline shockproof Heavy and the rest Redline MT-90 in my 6spd ever since my rebuild. Has never shifted better and my tranny temps went down a tad. 12k miles so far.
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Hey guys, for my normal driving, my gearbox is fine, not notchy or scratchy. But for the track, when flat shifted, I have a hard time not getting locked out here and there. I currently run MT-90 in the trans with a tiny bit of LSD additive.
What would you recommend I run if I wanted to change gear oil just for a trip to the track where not getting locked out is of upmost importance?
What would you recommend I run if I wanted to change gear oil just for a trip to the track where not getting locked out is of upmost importance?
I went to the 2 MT90 w/ 1 HSP and I have over 30k miles on this fluid mix with no issues at all. I have had HSP in my trans for 45k of the 55k miles on the odo, I live by the stuff and every change the magnet on the drain plug always looks good.
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I bailed on Shockproof in the gearbox due to the horror stories about parrafin wax clogging up in the oiling hole through the shaft (I forget whether it was the input or output shaft).
-Jalal