1kwikF

I am installing a shift kit on my 2002 trans am.

the shift kit is a sonnax HP-4l60e-01.

My question is - I was having an extremely hard 1-2 shift at part throttle and 4th wasnt locking up consistantly, but due to my tune, i wasnt getting a code.

I have read that installing most shift kits will fix both problems, but when i looked at the bore of the tcc on the valve body, and in order to properly install the kit I'd need to use the sonnax 77754-04k along with the associated reamers (about $300 in parts).

however, i have been advised to use the teckpak fitzall 1870 fixed valve ($15) as a much cheaper solution.

Ive installed the entire kit except this valve. The kit says to plug the pwm hole in separator plate, and not to install the isolator valve with their tcc regulator valve with spring.

The fitzall is supposed to be installed with the isolator valve and stock spring.

Im going to use the fitzall valve, but should i install it with the shift kit spring and plug the pwm hole, or should i not plug the hole and install stock spring and isolator valve?



any help is greatly appreciated. Id really like to get this done so i can get my car back on the road

1kwikF

any transmission experts have any ideas?

mrvedit

First, the expensive Sonnax kit is intended to repair the TCC valve while KEEPING the PWM (gradual) apply of the TCC.
In contrast the Fitzall and the Sonnax and Transgo shift kits replace the TCC valve with a simpler on/off valve. Most/all performance converters recommend an on/off valve anyway.

Since the Sonnax Performance Pack (shift kit) includes a modification to the TCC valve to make it on/off, you do not need to use the Fitzall.

If you decide to use the Fitzall, follow its instructions and ignore the Sonnax instructions related to the TCC and PWM. (I.e. use the original isolator valve and do not plug the PWM hole.)

I do not have the experience to suggest which is better.

So,
you don't need the Fitzall valve

1kwikF

I believe i do need the fitzall valve though as the tcc/pwn bore is loose and was causing my slip to begin with. the fitzall has o-rings to seal the valve.


Thank you, I can get my car back together now.

mrvedit

Yes, the Fitzall has the o-rings to better seal a worn TCC bore.

1kwikF

Thank you! Ill try and post an update when I get this done.