Ok..I am Assuming that the Redline MTL can be used in the Five speed Gear box.I am Wondering if I could also use it in the Differential too(n/A LSD)..asking this because I would like to run Synthetic,but I can't see why I would have to run Different Fluids,since If you can use 75W90 as a Trans and Diff fluid..then the MTL should be able to be used in Both?..am I Correct?.Thanks guys.In advance.Sincerely STYX!~

 

MTL eats synchros, true story. DSM guys stop using straight MTL cause the syncrhos were going to ****, redline confirmed it, it doesn't protect "yellow" metals. Now I dont' know if the rx7 has brass synchros but I played it safe and ran MT90. Put light weight shock proof in your diff. I think MTL might be a little thin for the diff. Just my .02 cents

 

They reccomend MT90 for the tranny, with the LSD you need a lube that's made for LSD's.

 

go with what specs say Dave thats what I did and she runs great no synthetics in mine .I asked a specailist he told me its ok to use synthetic on new parts sometimes ( again depends on specs )but when you use it on used or old parts since its a finer liquid it will find the smallest crack or hole or used Oring and leak like a sive .milk companies are gggggrrrreeaaaaatt lol

 

Actually ..I Found a Couple bottles of Redline(75w90)..cheap..too good to pass up.

 

redline also makes an additive that makes MTL/MT90 safe for LSD's

 

Hey Dave,

If you want Redline products go to NO LIMITS, in ottawa. Ask for mike.

Real good prices.

 

Funny you should mention that Azad..I Pm'ed him on Redliners.I am lookin for the address?phone # ?...and you have a Pm Budz..(crappy week)

 

Mike

613-748-7278

 

So what kind would be recommended on brass syncros and an LSD?

 

Or you can just buy LSD additive to add at a GM dealer.

 

or the ford differential treatment additive, i'm sure we all love to work with that.

 

wow... so much mis information in this thead. I wonder how many people actually followed the advice given.

MTL and MT90 is a GL4 oil. Mazda says you can run either GL4 or GL5 gear oil in the transmission. GL4 is preferred because its properties allow the syncros to have an easier time to match up their speeds. GL5 was never really intended for syncros. GL5 has higher shock loading, and will not break down as easily as GL4 under high temp. Hence it's usually what is recommended for differntials and transaxles.

You can put GL5 (redline 75W90NS) in but shifting will not be as good as GL4 (MTL/MT90). If you don't drive your car in the winter use MTL. The viscosity spread is not so big and hence it will perform bigger.

As for it eating syncros. It's been in my rx7 tranny for more than 8 years now. THe previous owner put in MTL. I put in MTL twice, and MT90 once. No issues at all.

I also use Redline in my subaru legacy GT. It calls for GL5, so I run 75W90NS in the front diff/trans and 75W90 w/ the friction modifier in the rear LSD.