1989iroc5.7

trans rebuilt with alto standerd rebuild kit (master) and new transgo seperator plate,corvette servo and .500 booster valve. if i hold gas pedal to the floor it doesnt want to go into 3rd. if i let up just alittle bit it will just fine.also if held to the floor at about 4500 in 3rd it just goes into neutral it seems and just tachs out to redline. any help would be greatly appreciated.

Floor guy

Tough to say. Take it back to the builder asap, before the warrantee runs out.
It could be something as simple as a tv cable adjustment.

1989iroc5.7

i rebuilt it.no laughing! My father rebuilt trannies for 5 years and watched over me as i did it.the tranny had the same problem before i rebuilt it.some people say it might be the governer. I adjusted the tv cable the way people say on here pull it all the way back and then hold the throttle all the way open and youll hear it click till you stop. so really the cable is all the way out when you are to the floor.

1989iroc5.7

one more thing could it be the converter or the fact that 3.73 gears have been installed??

88strokedmaro

hey mine does this too... but only when the car is cold.. tranny rebuilt not that long ago... most of the time it works great but....

1989iroc5.7

i figured since it does it when my foot is to the floor and dont if i let up just a tiny bit i would lower the tps votage alittle and take two clicks out of the tv cable.the tps voltage was 4.87 now im down to 4.62 at wot. it does seem to be better !!!! it now only does is it if i go out of my way to totally smash the pedal down hard as i can like im tring to go through the floor lol. one other thing i was thinking of tring is a new govener !! im going to start looking for a new one.

ES87iroc

Hey Freddy - any updates?

That TV cable looked a little raggedy, you might want to think about putting a new one on...

1989iroc5.7

ill try that and im also thinking of getting a new valve body.

CamaroMike

I was so sick of tranny companies not being able to design a tranny the way I wanted, I just programed my own valvebody. Thank goodness for having the GM Tech manual! If I ever buy a new tranny it will be full manual with engine braking.

If you want to nip this problem in the butt, do what I did. Start by blocking the part throttle and detent ports in the tv sleeve. This alone might fix the problem. If that doesn't work, then block the MTV down valve with a spacer and transfer the stiff MTV down spring to the MTV up valve. This will stop all automatic downshifting except on deceleration and only delay automatic upshifting on extreme WOT. Whatever you do don't block the MTV up valve as this fluid is used under WOT to allow holding of 1st gear. Your upshifts will be set at approx. to 5,15,30MPH for 2nd,3rd,and 4th. The real beauty is when you mash the go pedal you get instant MANUAL upshifts EVEN IN 4TH GEAR and still retain some level of automatic function in 2, D, and OD! The one down side is manually shifting into 1st above 20MPH is not possible because most shift kits use increased MTV up pressure to provide instant first activation!