trans not downshifting !

D

dave34

Member
Joined
Jul 23, 2009
87 gn , when coming to a stop trans will not downshift from 2nd to 1st at all . when i let off brake and go again its still in 2nd maybe even 3rd. also 4th gear is really delayed about 70mph. i had this very similar prob. 7yrs ago and it was tcc sol. and that fixed it . so i just put another new tcc sol. in .same problem. could it be bad or misadj. brake switch by pedal or possibly vss sensor? or is it mechanical problem . im leaning towards electrical because i know tcc gets power thru brake switch but this is where my knowledge stops. any ideas?

thanks
Dave
 
had same prob felt like stick shift and not putting in the clutch at the stop sign
before buyionmg one just unplug it at the tranny and drive it if i remember the connect is at the drivers side good luck
 
You might have some line press. issues, too much @ min. TV. Does it go into 1st if you nuetral it & go back to D or OD?
 
thanks for reply . yes it will manually go into 1st every time at a stop. just not on its own
 
on my direct scan the trans is only going into 3rd . the 4th gear light is not coming on which makes sense because it wont go into od now. also the tcc light comes on as soon as i go into 3rd and it stays on . so it seems that something is causing the tcc to stay on all the time at least when im in 3rd and till im stopped and then i manually have to goto 1st to start again. i did just replace tcc sol.and brake switch and same prob. but could it be in wiring somewhere also the f port on aldl conn shows 12volts with key on so i think sol. is getting power. i still think this is electrical prob. but not sure where to go from here
 
car wont go into 4th now at least to 75mph. tcc indicator on direct scan comes on as soon as i get into 3rd and wont turn off . car still starting in 2nd at stop. tcc solenoid and brake switch have been replaced.

anyone?
 
Id bet you have too much line at minimum TV so your getting second starts. Back off the TV cable one click at a time till you get it to drop back to 1st.
 
i tryed pushing detent conn. to firewall all the way and hit accel. with foot and it clicked back 1 notch so i test drove it like that and still basically does same . should i try pulling to front of car where it was but a little further or is that wrong dir. also would that explain tcc on direct scan as soon as im in 3rd . it will not go off
 
pulled detent all the way out and basically same prob except shifts less firm which makes sense. also i unplugged 4wire connector and still same problem . maybe not electrical after all. where do i go from here? and is this a torque conv. prob? or trans problem?. the trans is a eric shertz dynotech built 2004r. the torque conv is precision vigilanti multidisc, lockup. both only have a few race passes about 7yrs old but not many miles on either. defintely not abused. filter and fluid has been changed ,looks good. i did install pts deep alum pan with rear sump 2 months ago . everything was fine. takes 12 qts now though .
 
dave34 said:
pulled detent all the way out and basically same prob except shifts less firm which makes sense. also i unplugged 4wire connector and still same problem . maybe not electrical after all. where do i go from here? and is this a torque conv. prob? or trans problem?. the trans is a eric shertz dynotech built 2004r. the torque conv is precision vigilanti multidisc, lockup. both only have a few race passes about 7yrs old but not many miles on either. defintely not abused. filter and fluid has been changed ,looks good. i did install pts deep alum pan with rear sump 2 months ago . everything was fine. takes 12 qts now though .
Click to expand...
Put a pressure gauge on and post the minimum TV pressure
 
thanks for the reply . it looks like i can connect gauge on drivers side ,but can i get a gauge at local parts store or do i need to take it to a trans shop. i assume i need a gauge that will read 100-150 range. I rather do it myself if at all possible . i heard 55-65psi at idle is good with a quick change in pressure under light throttle , yes? no? and i still dont understand why direct scan is showing tcc indicator as soon as i hit 3rd and stays on?
 
dave34 said:
thanks for the reply . it looks like i can connect gauge on drivers side ,but can i get a gauge at local parts store or do i need to take it to a trans shop. i assume i need a gauge that will read 100-150 range. I rather do it myself if at all possible . i heard 55-65psi at idle is good with a quick change in pressure under light throttle , yes? no? and i still dont understand why direct scan is showing tcc indicator as soon as i hit 3rd and stays on?
Click to expand...
Does the TCC indicator stay on when it finally gets in 4th> Is it actually locking up? You need a gauge that will read up to 300psi if you want to do the test at full TV
 
yes, i managed to get to 4th once at about 75mph , and i think the tcc light went off but i will try again during the week to be positive , but when im driving along in 3rd the tcc light will go off if i let off gas pedal but as soon as i give the slightest throttle the tcc light comes on. i will report back . i will get a gauge this week also
 
thanks alot for this valuable info . i will check these sites out and get a gauge hopefully during the week and report back
 
finally got a press. gauge.

w/tv all the way to front of car {+-1000rpm idle}

p 75

r 125 (too low i think}
n 75
4 75
3 75
2 180-200 {too low i think}
1 180-200 { but sometimes this will fluctuate wildly}

w/tv all the way to firewall { 1000rpm idle}

p 125
r 225
n 125
4 125
3 125
2 180-200 {too low i think}
1 180-200 "

when i tapped throttle to test load pressure in each gear, pressure would change a little , but then it would not relax when i let off throttle , the pressure just stays high until i shut car off and start over or change tv under hood. this does not seem right to me it seems that maybe throttle valve spring is stickin or broke ,worn etc. if so do i have to buy whole detent cable or can i replace spring only , is it easy to do? im guessing i drop pan for this
 
thanks for the links. i talked to lonnie from extreme auto. and cant say enough of the guy he spent 20 mins trying to trblshoot my problem over the phone and its not even his build . he thinks the tcc indicator coming on as soon as i get in 3rd and not going off is prob chip and the 2nd gear starts could be a sticky valve in vb where the throttle valve pushes into ,not the throttle valve assembly. he says the pressures seem good enough. i ordered a new tv cable from him just to be safe, so as soon as i get it i can put things back together along w/ new tt chip i have. ill post with results.
 
does anyone know how the throttle valve plunger assem. is removed? i got vb out on bench and lonnie told me to check operation of valve on vb which the throttle valve pushes into . it looks like its pressed in . i didnt want to pull on it too hard and damage it . the plunger action seems real smooth by hand so maybe its fine. but lonnie , if i understood correctly said check ,clean if necessary the valve on the vb itself. but maybe i misunderstood him . also i have 3 check balls that i see is that normal. anybody?
 
dave34 said:
does anyone know how the throttle valve plunger assem. is removed? i got vb out on bench and lonnie told me to check operation of valve on vb which the throttle valve pushes into . it looks like its pressed in . i didnt want to pull on it too hard and damage it . the plunger action seems real smooth by hand so maybe its fine. but lonnie , if i understood correctly said check ,clean if necessary the valve on the vb itself. but maybe i misunderstood him . also i have 3 check balls that i see is that normal. anybody?
Click to expand...

There are roll pins the hold the valves in. BE CAREFUL, DO NOT MISPLACE SPRINGS or MOVE SPRINGS, OR CHECKBALLS!!!!. Also inspect the machined surface on the VB, make sure there are not scratches on it. Some valves may be sticky and harder to remove. If you have a set of picks you can usually get behind the valves and work them out.........Again BE CAREFUL not to scratch the bores or surfaces. Also check to see if the Valve Body is a CZ, BR.........

After you get the valves out, clean the inside of the bores and look for scratches. Richard Clark helped a board member recently with the same problem as you, turned out to have the wrong valve in the valve body (was'nt Stainless Steel). The valve needed to be smoothed with wet/dry sandpaper (I believe over a 1000grit) and the bore needed the same treatment. But you need special tools to go into the VB bores.
 
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