Okay I know this has been discussed before, and I have done searching and have found some helpful threads on the subject, but since a lot of the posts I have been looking at like 2+ years old, I thought I'd just see if anybody has any more recent updates with gear oils and stuff.

Here is my situation: On my '04 Evo RS, I put Neo gear oil in, and it has gotten considerably WORSE. When the car is cold, it's extremely hard to put it in gear. Even after it warms up, it's not easy. I should add in here another fact - I have a Cusco twin plate metallic clutch installed too, and perhaps this could be part of the issue (?)

I just wanted to hear from people who have used Redline and/or any other type of gear oil, and how it has worked out for you. Any input on the oils used in the transfer cases would be appreciated too.

Thanks everyone!

 

all i can say to you is diaqueen is the stuff

 

BG Synchroshift, GM Synchromesh, or stock Mitsu fluids for the tranny, and only Diaqueen for the t-case. I've looked at numerous threads also, but none of them give a long term perspective of alternate lubes in the tranny or t-case. The most I've seen has been like 3000 miles on other gear oils. Too short of a test for me to feel comfortable using other oils.

I know Redline now markets a fluid replacement kit for the EVO. And just thinking in terms of Business 101, they must be pretty confident that their lubes will work just as good as the factory stuff.

 

Yeah, I've noticed some positive remarks about Redline MT-90 and MTL, but none of them are for very long periods of time. If anyone out there has used these fluids for a longer period of time, please chime in Otherwise, I may opt for the stock fluid or perhaps the Syncroshift/mesh, as I have heard good things about them too.

 

I have used BG in a AWD DSM transmission for well over 100k miles. I broke a synchro well into BG usage (my bad) and everything looked fine inside- except for the broken synchro.

IMO BG is awesome- almost like new synchros in a bottle.

 

I switched to Royal Purple 75/90 in the transmission and it shifts worse than the factory fill. I will switch out to BG probably next year. This seems to be the class favorite.

 

Hi,

I have ~47K miles, still on stock clutch. I've used Redline MT-90 in the transaxle, and NEO RHD in the transfer case and rear diff.

I think it's important to note that the transaxle specifies GL-4 fluid, such as MT-90. If you put a GL-5 fluid in there, it may cause a problem for the brass IIRC. The transfer case and rear diff specify a GL-5 gluid, such as the NEO RHD. I've had great luck with the NEO RHD in my Evo and previously in wife's WRX. WRX guys complained that Redline did not work well, but NEO did. The WRX specifies a GL-5 fluid.

I emailed the NEO guys about a suggestion for the transaxle, and they recommended the NEO HD (NOT RHD). I think the RHD may not be the optimal choice for the transaxle, so that may be part of your problem if you put RHD in the transaxle. If you did put HD in the transaxle and had a bad experience, I'm glad I stuck with Redline...

Take care,

FB

 

One thing I noticed, in trying to find a good transaxle fluid, Ive been keeping fresh oil in there all the time - changed t-axe oil 5 times in 25,000 miles.

Currently run diaqueen frt/rr and Redline blend of MTL/MT90 for the t-axe.

 

I was not happy with the shifting of my tranny and wanted to use a synthetic fluid to try and improve it. I looked for a fluid that had the proper viscosity to allow the synchros to shift well, and was also a synthetic for added protection and life.

I looked at Redline but they don't offer an off the shelf fluid that matches the recommended GL4 75w-85w or 75w-90w for the EVO 5 speed and I wasn't interested in mixing.

I looked for other synthetic fluids but there aren't many synthetic GL4 fluids in the correct viscosity range.

I researched this forum for suggestions:
Bob is the oil guy:
http://theoildrop.server101.com/cgi/ultimatebb.cgi

This is a hard core lubricant forum that has a lot of experience. This forum recommmend the MTL-P fluid by Specialty Formulations as one of the best fluids money can buy.

http://www.specialtyformulations.com/products.htm

This is a small company that uses the highest grade materials available and spares no expense. MTL-P is expensive at +$35/gal shipped but it is the best option I found. It is specifically formulated for 75w-85w applications.

At the time I bought this it was rated GL4 only. It is now a GL4/5 rated fluid, but according to the company & forum no changes were made. My understanding is it was created as a GL4 fluid but is also compatible in GL5 applications.

I did alot of research on the oil forum and all my questions were answered. I have had the MTL-P in my car for ~7000 miles and am very happy with it.
It made a huge improvement in shifting smoothness and reduced gear noise slightly.

Good Luck!

Edit - PS: I spoke to TRE regarding recommended fluids for the transfer case and rear diff, their recommendation was stock fluid ONLY for both. He mentioned there are other options out there but if they are not completely compatible they could damage components.

 

Sounds good. You reminded me that my car suffered from the tranny "decel whine" when new, which was one reason I switched fluids early-on (at 1k and 5k miles). The noise has improved, so I don't really notice it now. Car is not quiet or anything, but at least it's tolerable and the drivetrain hasn't grenaded on me.

It's true that MT-90 isn't the exact viscosity recommended, so I've seen some people mix a Redline "cocktail" of MT-90 with MTL (75W 80) which approximates the 75W 85 spec.

Take care,

FB