lost 2nd gear for 2nd time
05-02-2005, 08:51 PM
#1
10 Second Club
Thread Starter
iTrader: (3)
Join Date: Mar 2004
Location: orlando, fl
Posts: 4,266
Likes: 0
Received 0 Likes
on
0 Posts
lost 2nd gear for 2nd time first time was on stock trans. just one day, no upshift from 1st to 2nd. so pulled trans. nothing found to be wrong with it other than the 3-4 clutches worn. even the band was fine. so, rebuilt anyway. had all the parts. even got the torque drive (hardened input shaft/drum assembly) from transmissioncenter.net did the works thing. shift kit, larger boost valve, Z-PAK 3-4 clutches, and so on. reused stock converter.
after about 1500 miles, the 3-4 clutch pack burned up. nothing else. can't find a reason for it. so, put another Z-PAK in. this time i added the yank py3400e converter.
now, went to track after 1700 miles and made four NA passes. on the 200 n2o pass, it banged off the rev limiter, then shifted from 1st to 2nd. same thing on the 2nd to 3rd shift. made it all the way down the track. coming back up the return road, i noticed no upshift from 1st to 2nd unless lots of rpms. so figured i'd make another pass. took off, hit the button, no upshift at all from 1st to 2nd. let out and went home.
now, i'm back to the original problem. have a line pressure gauge on it this go around. at WOT pressure is max 240 psi. normal acceleration is in the 180 psi range. idle in gear and cruise with no throttle input is 90-100 psi. i just put in the pinless 1-2 accumulator just for giggles (first time around replaced the 1-2 accumulator with an aluminum 700R4 one because found 2 crack in the plastic one). no change. tried upping the line pressure via the vhp handheld. no change. i've got one place telling me either the valve body is cracked or trans case is worn.
i don't believe the trans case is worn out. (56k at the first rebuild at 60k now) problem, as you can see, isn't consistent. but, second time the 1-2 shift failing. watching the gauge, in 1st about 35% throttle, pressure is 180 psi. when PCM, requests 2nd, the pressure goes straight to 100 psi and stays there. when PCM see no upshift, it commands 3rd, pressure goes up and shifts from 1st to 3rd.
for year 2000, you can put the selector in 2 for 2nd gear start. pressure jumps to 180 psi but no 2nd gear engagement. it stays in first. i have 4th gear as well. from reading, i know the "A" solenoid moves for the 1-2 shift. then goes opposite for 4th gear. my trans guy and i are thinking something in valve body. but can't find anything.
anyways, any ideas????
after about 1500 miles, the 3-4 clutch pack burned up. nothing else. can't find a reason for it. so, put another Z-PAK in. this time i added the yank py3400e converter.
now, went to track after 1700 miles and made four NA passes. on the 200 n2o pass, it banged off the rev limiter, then shifted from 1st to 2nd. same thing on the 2nd to 3rd shift. made it all the way down the track. coming back up the return road, i noticed no upshift from 1st to 2nd unless lots of rpms. so figured i'd make another pass. took off, hit the button, no upshift at all from 1st to 2nd. let out and went home.
now, i'm back to the original problem. have a line pressure gauge on it this go around. at WOT pressure is max 240 psi. normal acceleration is in the 180 psi range. idle in gear and cruise with no throttle input is 90-100 psi. i just put in the pinless 1-2 accumulator just for giggles (first time around replaced the 1-2 accumulator with an aluminum 700R4 one because found 2 crack in the plastic one). no change. tried upping the line pressure via the vhp handheld. no change. i've got one place telling me either the valve body is cracked or trans case is worn.
i don't believe the trans case is worn out. (56k at the first rebuild at 60k now) problem, as you can see, isn't consistent. but, second time the 1-2 shift failing. watching the gauge, in 1st about 35% throttle, pressure is 180 psi. when PCM, requests 2nd, the pressure goes straight to 100 psi and stays there. when PCM see no upshift, it commands 3rd, pressure goes up and shifts from 1st to 3rd.
for year 2000, you can put the selector in 2 for 2nd gear start. pressure jumps to 180 psi but no 2nd gear engagement. it stays in first. i have 4th gear as well. from reading, i know the "A" solenoid moves for the 1-2 shift. then goes opposite for 4th gear. my trans guy and i are thinking something in valve body. but can't find anything.
anyways, any ideas????
