1998Slow 'Stang

I changed out my funky looking fluid in my t45 (probably from the factory in 98) for some Penzoil Synchromesh. So far (2 days now) the shifter feels phenomenally better since the swap. It's much easier to shift whether the trans is cold or hot. Anyway, that's my story. Anyone have as much success with it as I did?

Unsullied_Spy

Long story short I had a seizure a few years ago and my Mustang ended up in a swamp. Got most of the work done at a shop then drove it home to finish the work not knowing my tranny had gotten a ton of water in it. That did enough damage that regular Valvoline Dex/Merc (filled to 3.8qts because I hadn't heard of the TSB yet) left me popping out of 1st gear, tough to get into 2nd, and wouldn't go into 3rd above 3,000 RPM. I drained it and added 1 quart of Synchromesh and 2.2 quarts of Royal Purple ATF (though now I'm told Mobil 1 is better and cheaper) and it is working much better. This is with the TR-3650 but definitely happy with the results, it has put off my transmission rebuild for another couple of years.

EDIT: My next fluid change I may try Red-Line MTL, it's supposed to be pretty good stuff. I'll be sure to share my experiences with that stuff when that day comes.

FlamingoGT

I may very well be wrong here and you would be advised to research this yourself before acting on it, but I am almost sure I read somewhere that it is bad to use synchromesh in a T45 as it does something to the liner.

... ok, I searched and here is where I saw it:
https://mustangforums.com/forum/4-6l...t45-trans.html

1998Slow 'Stang

Well, I already acted on it before posting this...heh... Anyway, while I respect Uberstang's opinion, I've also heard the exact opposite from more than one person. The big one that stuck out to me is a gentleman on Stangnet.com's forums, who has worked for Tremec for a number of years and now works for American Powertrain, and he says there is nothing wrong with putting it in the T45...as well as supposedly runs it himself.

Guess we'll just have to wait and see if my transmission implodes or explodes or turns itself inside out....(Hopefully it doesn't)

uberstang1

Keisler Transmission and promotion performance highley recommend to NOT use a synchromesh fluid in the t45 because it deteriorates the liner. So I went with royal purple ATF, but I don't have any expereince with synchromesh in my car.... I can say my t45 has a whopping 140k miles on it and was the original trans when I bought the car in 2003-04 and ive done nothing but beat the living snot off it and it shifts like butter every gear still.

96meangreengt

I have been running gm sycromesh for the last 2 years and no problems here.

1998Slow 'Stang

I don't know much about transmissions, what liner are you speaking of specifically, Uberstang?

uberstang1

The liner actually refers to the blocker rings, in a t45 that is stock the blocker rings are composed of a paper/organic liner, when the synchromesh fluid is used the additives in the synchromesh actually increase the deteroation of the liners. Aftermarket "Built" transmission or some more modern transmissions use a carbon/kevlar liner for the blocker rings where the synchromesh will be suitable.

Repzard

Mobile 1 ATF ...FTW !!!

All the rest like RP are money scams IMO and NOT designed for our trannys
My T45 shift much smoother\better running M1 than anything else I tried.

Jay-rod427

I put Mobil 1 in mine at 84K and didn't notice anything special in shifting easier or anything. Now after 2 seasons of drag racing it regularly(prob 200 passes) the gears are getting pretty hard to get into gear, I am not blaming the fluid but the regular abuse. Bring on a C4!!!