Need some quick advice on tranny fluid!

[tek_88]

Okay, so I accidentally put in a quart of Redline 75w-90 GL-5 in my transmission. I was pumping in Redline MTL, MT-90 and I accidentally grabbed the GL-5 by accident and didn't realize I had done so until I saw the MT-90 sitting there. Right now as it sits the transmission has one quart of MT-90, MTL, and 75w-90 GL-5. My question is will it be okay to run the transmission like this? Or should I drain a quart and add the remaining MT-90 into the transmission? Any advice is appreciated, it was dumb of me not to check the bottle beforehand but I rather not buy more redline fluid cause it's quite expensive.

 

[GSTwithPSI]

The Mitsu FSM says any API GL-4 or GL-5 lubricant with a viscosity of SAE 75W-85W. It's common to run a 75W-90W, though.

However, your synchros won't last if you run the 75W90 GL-5 Gear Oil. It is for differentials and such. It's too slippery for synchronizers, and will result in notchy shifting ultimately destroying them. Right from Red Line's site in regard to running their 75W90 GL-5 Gear Oil in transaxles: click

This product is not designed for use in most manual transmissions or transaxles in passenger vehicles, since the extreme slipperiness may cause synchronizer mesh issues that lead to shifting problems

So, yes, you need to drain it out. Sadly, you need to drain EVERYTHING out and start over. You can't just drain out a quart of fluid and add some new on top. You've already mixed them, so now everything has to come out and new stuff be put in fresh. It's better you make a $30 dollar mistake now, rather than destroying your trans and making a $1,000+ mistake later.

 

[Spyke169]

Hate to say, but the GL-5 is corrosive to the brass synchros. Best think out he to drain it all and refill with the correct gl4 fluid . How much that little bit may hurt, hard to say.

 

[tek_88]

Alright thanks guys. I'll take your advice and drain everything out. Hating myself so much right now, lol.

 

[coyotes]

its not too hard to do a transmission flush, no big deal.

 

[GSTwithPSI]

Quoting tek_88:
Alright thanks guys. I'll take your advice and drain everything out. Hating myself so much right now, lol.



sh*t happens. At least you asked before just going with it. You may have just saved yourself a transmission.

Pro tip: remove the speedo gear and get one of those long transmission fluid funnels. Stick the long transmission funnel (or a typical funnel with a hose attached) into the speedo hole, and then dump in exactly 2 1/2 quarts of MT-90 (spec is 2.4 qts). It will save you the hassle of pumping it in.

You still have to pump it in the rear diff and xfer case, but they have small capacities compared to the trans.

 

[tek_88]

Thanks for the tip GSTwithPSI, that sounds way less of a mess than pumping it through the fill plug.

 

[G]

This is the best $15.00 I've ever spent. click
Works so well on rear diffs, trans, front diffs, center you name it. I've used it on all kinds of 4wd trucks etc....and no mess! It's 24" so you can fill it from outside the vehicle. /ubbthreads/images/graemlins/worthy.gif

 

[tek_88]

That's awesome, I just ordered one. /ubbthreads/images/graemlins/smile.gif