Anyone Run Redline MT-90 in Manual Transmissions?

[happyguy007]

Hey guys, I am using Redline MTL in an Mitshubishi Lancer made in year 1997, which require a gear oil vicosity of 75w85. I notice the shiftability of the gearbox has greatly improved, at expense of slightly noisier gear noise (whine at highspeed). Since i live in hot climate,im wondering if i should use a thickier vicosity of 80w90 gear oil?

After i read the Redline's wedsite, it is stated Redline MTL is not suitable to use for Hypoid Gear. However in a FWD car, the differential is build togather with the transmission. Unlike the RWD cars where the differential is a seperate unit with transmissions. Now i worried that if MTL would not provide enough protection to my differential. Would MTL protect my syncro at a expense of wearing out my transmission at a faster rate? I need you guys' opinion.

 

[unDummy]

MT85 would work protect better. Change the MTL out.

 

[happyguy007]

Thanks for the kind advice. But locally i cant find any MT85 yet. Perhaps i shall try MT90? Im wondering is there anyone who had use MTL and faced problem?

 

[unDummy]

Go 50:50 with the MT90 and MTL. Should give you the protection you need without affecting the shift quality much.

 

[happyguy007]

Thanks for the kind advice. Can i run the MTL now for 10k miles before dump it out? since i just fill it in. If MTL is really harmful to my transmission, then i would have to dump it out...

 

[unDummy]

I think that your best bet would be to drain out just a quart, and top it off with a quart of MT90 now. Then, drive it 15k-25k miles and change it with the 50:50 blend or another 75w85 MT fluid.

 

[Geonerd]

Running straight MT90 in my 92 Accord.

It's noticeably smoother (presumably thicker) during the Aridzona summer. I was up in Flagstaff a few weeks ago, with lows around 10F - the transmission shifted just fine when cold and did not feel sluggish in the least. (Yea, I know 10F is downright toasty by Wyoming standards.)

 

[Audi Junkie]

It's all climate specific. Also, horsepower matters too.

Take the Astra, it's 75w-90 from the factory...140hp. Stiff as a board in cold, it made no sense. I understand some people use M1 ATF in the cold, def worthwhile, but maybe good only for a year or two. My wife takes short trips to work etc in the Astra, so I went with Fuchs Silkolene Pro SRG75 Full Ester Race (GL-4). That stuff shifts like butter. I'm sure she could run it on ATF if we were in a colder climate.

In the new VW, we've seen the MTF as a thin 6cSt. I understand too that the fluid was "changed" for the 6-sp box like mine to reduce noise complaints. I assume it was changed thicker. So, because my ECU is flashed to 340ft-lbs, my solution was to go up (afaik) to a mix of MT-90 and MTL 70w-80 to 12cSt.

If the factory stuff was 14cSt I'm good because Redline and the Fuchs use a base oil that protects like a thicker grade. I'm pretty happy with the result, VERY nice power delivery. I would have just got the 75w-85 but I already had 1q of MT-90 and am comfortable mixing, so I got 2 MTL 70w-80.

Just to correct a misstatement, GL-5 will not corrode from "sulphur adds", it is simply slicker for gears, as it is a GEAR oil.

I go w/a slight overfill. The Astra speced 1.7q, but a TSB said to overfill to 2.4q if the customer complained about noise. I figured 2q was fine, as 1/3 a quart of $20 fluid sitting on my shelf would do me no good at all.


The best solution for MOST MT applications is Syncromesh, which is GL-4.


Just a a side note, the Redline models and Euro GM models spec only a single MTF change at 6000 miles. I had it done like 4000 because the Saturn dealer was closing. Also, the fluid speced for REFILL service in USA market was GM Transaxle lube...plain Dexron, afaik.