4T60 trannies clearly are the V6/V8 longitudinal auto choice, but I have a low mileage 4T45 in my pile. The 4t45 owhich is tied to many 3400 cars has a few more lbs of torque than the 4t40. I have noted a V8 build on the 4T40 which must be due to "it was in the pile so I used it". At 205 ft torque the 4t45 would seem a beefier and probably cheap replacement for a TH125 and maybe a stock V6. There doesn't seem to me much love for it here though. Any opinions or ideas. I have a low mileage one sitting in a pile and a potential duke project. Having said that unlike manyI have yet to tear up a TH125 behind a stock duke. But it is there, I must do something with it.

------------------
FieroDriver--Multimedia by J "Wudman" Wood--Wud's Photo BlogsBlues in St. Louis--Artists & Musician Marketing Blog--Sharing Social Media Marketing Tips

You need to computer control it.... so many people doing engine swaps are not typically going to want to upgrade to a different PCM.

quote Originally posted by darkhorizon: You need to computer control it.... so many people doing engine swaps are not typically going to want to upgrade to a different PCM.

Thanks, off to Craigslist it goes...

4TxxE needs a PCM. (Powertrain CM)

4Txx needs nothing for shift control. (Needs Manifold Vacuum) ECM controls TCC Lockup only. ECM for Fiero, with some wiring, can use it fine.

Number mean:
yMxx(E)

y = # of forward gears (TH125c update name is 3T40)
M = T/L Transverse/long mount
xx = relative strength and usual using these #: 40, 45, 60, 65, 80
E on some model means Electric Shift

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 01-12-2011).]

I am pretty sure I have the 4T45 not the 4T45e

Most people don't like/love it because most can't get it or doesn't know about it, etc.
And what engine does trans bell housing bolt to...

If engine can have a th123 then switch to 4t45 is a good choice If your not going to race. (Assume trans fits.)
I don't have much on 4t45 gearing. use google etc
I found this page... http://en.wikipedia.org/wiki/GM_4T40_transmission

also... trans is newer... see wiki. right box in page.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 01-12-2011).]

I was there to find out basics of this transmission. In any case, thanks for the response. I will put it up against one of my other "pile" TH 125C transmissions to match up the bell housing.

------------------
FieroDriver--Multimedia by J "Wudman" Wood--WordPress on a Budget For ProsWud's Photo BlogsBlues in St. Louis--