4t60 (Page 1/2)
TXGOOD AUG 16, 01:17 PM
I have aquired a 4T60 transmission for my car and I will probably have questions although I will search because I know there are articles out there about the swap.
My car has a 3.4 and I`m wondering when you get a torque converter for it would I get one for a 3.4 engine or for a 1990 Cadillac Deville, which is what the tranny
is out of.
Or are they the same?
Also, will the flex plate on the 3.4 work with the torque converter for that car?
Thanks

Well, I have sort of found one of the answers to a question.
It looks like the Fiero uses a GM42 amd the Deville uses a GM71
All of the measurements are the same except the Fiero has a 2095 stall and the Deville has an 1895 stall.
I have read that it`s better to have a higher stall, maybe even a 2300.
What do you guys think?

[This message has been edited by TXGOOD (edited 08-16-2019).]

olejoedad AUG 16, 02:06 PM
Change the converter.....
TXGOOD AUG 16, 02:25 PM
Should I use the higher stall like in the Fiero or the one for the Deville?
Johns 4.9 AUG 16, 05:29 PM
Hi,
Could you clarify which 3.4 engine you have? I would use the higher stall converter. It will give you a better launch. I'm using a 2800 stall converter with an 89 4.5 and 4T60. That's probably to much for a daily driver. They all seem to be interchangeable. They also make shift kits for the 4t60.
Cheers
Raydar AUG 16, 06:31 PM
The '90 Deville engine (4.5) is a torque monster, like the 4.9. It works better with the lower stall.
I would be inclined to use a higher stall converter. If not from the 3.4, then from another V6 application of that trans.
Just make sure that the pump drive (splines?) and the "ears" on the converter will work with your trans. (They probably will, but it bears mentioning.)

[This message has been edited by Raydar (edited 08-16-2019).]

TXGOOD AUG 16, 09:33 PM
Well the ones from Oreilly list basically the same torque converter specs for the Fiero or 3.4 and the Deville.
The only difference looks to be the stall which is higher for the Fiero.
And that makes sense comparing the 4.5 to the 2.8 as far as torque goes.
So, I think I`ll use the higher one.
cmechmann AUG 16, 10:15 PM
I kind of ran into something like this when I hooked up a 4T60e to a 3800 Vin 1 series 1.
On the Series 1 3800 it only had one set of torque converter holes. I had found that the 1995 Grand Am 4T60e transmission used the same guts and final drive as the 1994 Park avenue Ultra, but didn't have the HD output shaft and housing. This made it much easier to make up axles. However the Grand Am torque converter being a higher stall was also smaller and lighter. I had to carefully drill the flywheel to accept the Grand Am torque converter. When I went to Series II, those engines had both sets of torque converter holes.
Now I'm not as familiar with the 4T60 as I am with 4T60e, but I would bet they did the same thing with cars in different body models. I would look for a converter for a Wbody with 2.8 or 3.1 4sp auto. Most of them were 440T4 or 4T60s.
By what I had seen the main difference between a 440T4 and 4T60 was the right output shaft housing and valving. Early 440T4s had a common habit of granading the final drive and it would break the case. Later 4T60s had a removable final drive housing like 4T60e-4T65.

[This message has been edited by cmechmann (edited 08-16-2019).]

olejoedad AUG 17, 08:36 AM
Any idea which sprocket set and differential are in your 4T60?

35/35 and 3.33 are great for a Fiero.
rlndhill AUG 19, 07:37 PM
I have a highly modified 2.8L and the 125c trans (3.33 FD). Look at a DACCO Torque Converter B21FZ2 (2,375 RPM). I did a lot of research before I decided on the DACCO. It's a Fiero OEM replacement and is very reasonable. Custom shops wanted to charge me $400.00 to make me a converter with the same specs as the DACCO.
TXGOOD AUG 23, 10:17 PM
Well, I picked up a transmission today but I can`t find anything about it.
The plate has 610KCH on it plus W190H
It`s suppose to be out of a 1990 Cadillac Deville.
I found the 0 after the 61 does mean 1990 but I can`t find a designation of the KCH
I found the KDH, KPH, KHH but no KCH.
I did find a KCH listed on Autozone but it showed for a Fleetwood, which I think was a rear wheel drive car.
I guess I can install it and see what happens.