Chindit

I used D4 Red Line ATF for my manual transmission. Then read somewhere 2000 and below you cannot use synthetic oil!

Anyone done the same and had issues?

It's been the gearbox for four weeks now.

Amazon website, and Redline say it's ok to use😐

DetroitPlac

I've had Redline D4 ATF in mine for the entire year (including some track days), and no issues yet. In fact, the transmission shifts way better than it did before. I'm not worried about it, you probably shouldn't be either.

dadaroo

This is what I have ben told.

Amsoil synthetic ATF and Amsoil torque drive synthetic ATF are THE ONLY synthetic transmission fluids compatible with the pre-2001 m6 transmissions. It is the only synthetic ATF that has additives to counteract the swelling of cellulose compounds that occurs when they are exposed to synthetic ATF.

The cellulose components are the blocker rings (replaced with carbon fiber in 2001), and if you use anything but traditional petroleum based DexIII ATF or the above listed Amsoil fluids, you are ruining your transmission. Using the wrong fluid is not something you will notice until about a year or two after the fact, and it cannot be reversed without a rebuild.

Amsoil torque drive synthetic is the better of the 2 Amsoil fluids, and is hands down the absolute best fluid you can put in your pre-2001 m6 transmission. Personally, I would still use it in a 2001+ m6 or m12, and many people do.


Mr. Sam

johnson-rod

+1 for the Amsoil Torque Drive. I've had it in my transmission since 2008 and well over 100K miles. It still shifts like 'buddah'.

muggsd27

+2 for the Amsoil torque drive it's been in my 98 for over 2 years

jackthelad

I ran Mobil 1 ATF (DEx III) for many years in my '98 - it was put in by the dealer on a fluid change way back when. When shifts started getting balky maybe a year or so back, and a few unexplained "grinds" occurred, I swapped to Valvoline's DexMerc - a Dex III non syn fluid. Cheap as well. It's been in close to a year now, and the tranny is shifting perfectly - and has since the fluid change, and for most of the time I was running the Mobil 1.

Now mine was one of the very first '98's, built on Day 4 of the production run. So, it may have a pre Tremec (Warner built) 6 speed- I don't believe they sold that business to Tremec until 1998. Does it make any difference? Who knows.

Anyway, I have definitely issues with the "lasting damage" theory as my own experience directly contradicts that assertion.