High Stall Torque Converter

[Husky]

Here is a list of the Torque Converter suffix codes.

A- 2795 rpm
K- 2760 rpm
B- 2560 rpm
C- 2385 rpm
Z- 2375 rpm
G- 2095 rpm

As far as we can tell, all converters will work in all trans.
And the '98 + 4 cyl converter will yield ~3000 rpm behind a healthy V6.

If anyone has further info, please correct this.
Thanx

Out of curiosity, what TC came in what car? I'm about to go order one in, but I need to know the vehicle or the GM part number.

[GPTuner]

i would like to know this as well, my 3100 has dead spots that a higher stall would fix up pretty well

[EspanolaGuitarista]

Thanks for all this information...

I was wondering about the same thing. When I get a new stall I'll drop a site donation into paypal. Thanks people!

[z284pwr]

GM FWD Torque Converters

GM uses the same type 4-digit ID method of identifying FWD torque converters as with the RWD units, however the digits have different meanings. All 125-C, 440-T4, 4T60, and 4T60-E transmissions use the same style torque converter, and they are interchangeable before 1996. 1996-up converters are built to be compatible with GM's PWM TCC apply strategy which means that you can use the newer converter on the older trans, but not the older converter on the newer trans.

1st Digit (application trans)

F -- 125C, 440-T4, 4T60, 4T60-E
2nd Digit (approx stall (depends on engine)

A -- 2795 rpm
B -- 2560 rpm
C -- 2385 rpm
D -- 2095 rpm
E -- 1865 rpm
G -- 1630 rpm
H -- 1515 rpm
J -- 2060 rpm
K -- 2760 rpm
L -- 1895 rpm
M -- 1525 rpm
Y -- 1420 rpm
Z -- 2375 rpm
3rd Digit (TCC clutch material)

0 -- Clutch omitted by factory
5 -- Clutch contains poppet valves
All other digits (pre 1996):

Red Fiber material
1996-97

C, E, H, K, P -- Carbon filled clutch
1998-up

F, H, K, Q -- Woven graphite clutch
4th Digit (Clutch Type)

B -- standard
C -- viscous (stay away from these type)


Pertaining to the TCC Clutch material: starting in 1996, GM implemented a new TCC apply strategy. The 1996-97 trannys (exc 3T40), used a soft-apply (PWM) TCC strategy which was designed to soften the TCC apply so the "customer" would not feel it come on. This means that the PCM is actually making the TCC slip during apply. Only Carbon clutch torque converters should be used in 1996-97 trannys. You can use the carbon clutch TC's in earlier trannys that did not have PWM technology, however the lockup feel will not be the same. However, I have heard that these carbon clutches rarely burn-up or go bad. I have personally used the carbon filled clutch TC's on earlier trannys and the only experience I have witnessed with them is they apply firmer.

Starting in 1998, GM revised the lock-up strategy once again only this time the TCC may never completely lock up and may always slip about 20-60 rpm, depending on the vehicle. This means that even the carbon clutch units would not work well for these applications thus GM started using woven-graphite TC clutch material. I have heard that the woven graphite TC's should not be used in any earlier transmissions because the lockup will not work correctly.