ZzTeaRs

Alright today was opening day at the local track so i took my 94 z28 out to get a good baseline before i put the mods into it. Normally when i drive the car around town im never going full throttle i just granny drive it around town. But today at the track during full throttle everytime i went down the car would not shift from first to second and i would hit the rev limiter. same for second gear. so my question is should i start looking for a new trans or could it just be something minor? i figured i would ask on these forums before trying to google around and possibly get a wrong answer. Thanks guys

best time of the day was 14.53 @ 98mph with about 3/4 the throttle ( it shifted that pass)

RamAir95TA

iTrader: (2)

Any mods?

ZzTeaRs

None that i have put on it yet but it does have a CAI and the cat has been removed from the previous owner

ZzTeaRs

http://youtu.be/KN-fBpvyvcA

video link if it helps

puddingmmmmmmmm

iTrader: (3)

Out of curiosity have you checked the fluid level and condition? Could be possible the clutches are going up, even though it doesn't do it at part throttle. Could be the torque converter, solenoids going bad, a lot of possible causes...

ZzTeaRs

ya the fluid levels are perfect, going to try and flush it out and change the filter and see if that helps tomorrow but im in the dark about trans stuff. Just figured i would ask here before i took it to the local trans shop

puddingmmmmmmmm

iTrader: (3)

Around where I live most trans shops do free diags. Worth checking some out some by you to see if they are the same way.

Noah's95z28

iTrader: (7)

Has it had a gear change or rear end changed? That will throw the timing of your shift points off in the comp. Possibly changing tire sizes and rim size will throw it off just enough as well.

nitrous2fast

iTrader: (2)

The computer gets its speed from the trans... so changing tires/wheels/gears will have no effect on shifting..

puddingmmmmmmmm

iTrader: (3)

You couldn't be more wrong. Assuming his car still has the 4l60e it came with the car the PCM controls shift points. Changing tire size or gears will effect shift points. My speedo was 10mph over for a long time because of a PCM I had put in that was from a car with 2.73s and smaller tires. I forgot I didn't switch my original back when I was trying to diagnoise a problem. My trans would shift early.

Noah's95z28

iTrader: (7)

This is spot on ^^^^Thank u.

RamAir95TA

iTrader: (2)

nitrous2fast is 100% correct.

The transmission doesn't care what tires/gears are on the car. It will always shift when the PCM tells it to. You think the shift points may be different when you change tires/gears, but that's only the DRIVER'S perception. In reality the PCM is still doing what it's supposed to.

Noah's95z28

iTrader: (7)

Well I know when i went from 2.73s to 3.42 gears if i hammered on it, all it would do is bounce of the rev limiter. I had to let off the throttle before each shift. I had to send in the comp and have the speedo re-calibrated and the shift points had to be changed as well. Worked great after that.

05HD

If it only does it on the 1-2 shift and the 2-3 shift is fine, it is internal to the transmission. Most likely a slipping 2-4 band or reaction sun shell teeth starting to strip.

05HD

Edit- I watched the vid. If it was the sun shell, the teeth would all be gone after that and you would be missing gears.

ZzTeaRs

as far as i can tell neither the tires or the gears in the rear have been changed, the person i bought it from didnt know much about cars so i doubt he changed the gears in the back, it still has the stock rims on it also. I drove it this morning to see if it was any better, it now feels like its shifting into first pretty hard even at low speeds