Manual Trans fluid also known as Gear Lubricant.

I am trying to make my 6spd shifting smoother. Has anyone tried changing w/ different brand of lubricant and see improvement? Redline MT-90 for example?

 

I changed to MT-90 and it made shifting sooooo much smoother, especially early in the morning when the car is still cold.

 

yeah I've noticed when i shift in the morning it feels kind of "Jerky" and especially when I shift to 3rd, it makes a little "click" noise. It disappears after I warm up the car.

 

I think the question needs to be adjusted to say "in thier 6-speed." Because the 5 and 6 speed transmissions seem to respond differently to the MT-90. I, as well as a few others, are not happy with the MT-90 at all.

 

What else is there besides Redline MT-90? because I really want to make this "Jerky" shifting better.

 

You can try the Royal Purple brand of 90 weight gear oil. They sell it at local auto parts stores.

 

I put the MT-90 in mine, actually seems to be a bit notchier into 2nd, and can't really notice much change in the others.
Will probably go back to the factory fill (anyone know what that is?) in a few thousand miles.

 

I hear Amsoil also makes an acceptable GL-4 gear oil for the Max.

 

So is there any consensus that changing the lubricant makes any difference? Because I have a 2K3 SE 6 speed and I find it hard to shift into 2nd and 3rd when the car is cold (it kind of feels like the syncromesh(sp?) is not working). Will changing the lubricant fix this problem? Or is there something actually wrong with my transmision?

 

Yes, Amsoil does have gear oils available for both the 5 speed and 6 speed.

People have been reporting mixed results with changing the gear lube in a 6 speed. Half seem to love it, half don't think it helped much.

 

I put in MT-90 and in the winter you will not notice a difference on start up. However the tranny becomes smoother much quicker than it did before, in the summer and winter. I also have the "clicking" going into 3rd when it is cold. The MT-90 did not fix this. The tranny just needs to warm up. I have 21k on mine and I have noticed that it seems to shift smoother, so maybe it just takes a while to loosen up.

 

I found the same thing on my 5 speed. It was definietly "notchier" (especially when cold).

Also....

I dynoed the car on the stock fluid and stock engine oil, then swicthed to Redline MT90 in the trans and Mobil 1 5W-30 in the engine. There wasnt a bit of difference in the amount of power making it to the wheels.

So much for the reduced friction making power argument.....

 

I don't believe any engine oil is going to make a difference in dyno HP, but I could be wrong. As for the tranny, the better fluid is really to protect the synchronizers and help them do their job more consistently over the temperature range. That isn't going to affect dyno HP at all. If you used a better fluid in an ATF, maybe, I can't say for sure. As fo notchiness, I think it just takes a lot of time to break in the tranny. In addition, the gearbox seems to be very sensitive to your throw, at least in my case. Overall, as long as the MT-90 fluid protects the synchronizers, I'm happy.

 

Well said!

 

I can't testify to the manual 90 weight, but I am extremely satisfied with the ATF from Royal purple. In my auto, it seems that the tranny is transferring the power smoother and alot more efficiently. I can also say that I've seen a rear end out of a truck with 250,000+ miles on it get serviced. The purple dif fluid poured out clean as day, and when the cover was removed, the ring, pinion, carrier, and locker in this bohemoth mud truck were pristine. Right then, I was sold.

 

I guess the only true way to find out is to try both and see which one comes on top. Royal Purple Vs. Redline Its on BABY!

 

I just purshcased the AMSOIL Full Synthetic 90w for my Max (thanks iwannabmw...) but have not yet installed.

I don't even have 5k miles on my '02 yet, and was wondering if switching to a full synth THIS early is appropriate??

Anybody have any comments on a longer "break-in" for the tranny before switching over???

I'm kind of reluctant after the last rash of threads that popped-up stating that the FULL SYNTH. HI-PERF. Lube was not really making THAT much of a difference in the 5th gen 6 spds.....

I'm getting confused!!!

I figure the same as nismotech.....just gonna have to see for myself.

input is welcomed.

g.r.

 

The best way to find out which is better is to get some MT-90 and Royal Purple 90 and put the same amount in the refrigerator overnight and the next day find out which one is thinner (less viscous) and that one would be the best fluid to use (especially in the winter time). Anyone want to volunteer and test the different fluids out?

 

I will be more than happy to test it for you guys....but the thing is I cannot find the store that carries either of these product in my area.....so ****ed off...

 

Don't forget about BG Synchroshift II. Its a synthetic GL4 approved blend. I'm going to try to get my 2k2 done tommorrow. Will post results.

Jesse

 

That would only tell you how well they flow when cold. It will tell you nothing about the level of protection and resistance to high temp. oxidation the fluids will offer when warm. I would think that those would be more of a priority with the easier cold weather shifts an added bonus.

 

First I've heard of this oil. Is it a synthetic? And, where can I find some . . . Thanks!