First off let me say im new here and need some help after my recent gear swap. I have a 1995 Z28 with headers, CAI, TB plenum, Cat delete, 160tsat and a 1 year old rebuilt auto tranny. I recently changed my ratio from a 2:73 to a 3:43 rear gear and am having severe issues. First off the gear is from Richmond and whines at real low speeds and right when put under initial load, secondly when i give the car hard throttle (its an auto) its like holding the clutch in on a manual and it hits the rev limiter and wont shift, when you let off the gas it finally shifts. When i first bought the car it had the same problem, but i rebuilt the tranny. Im at my wits end here and really upset so any help would be nice

thanks..

 

Have you have the PCM programed for the new gears ? this is a must or things will not work right

 

no i havent reprogrammed the computer. Is thier anyone in particular i should use for this? I had a hypertech tuner on it, but it didnt make any difference

 

The trans will not function correctly without the proper VSS signal and if you haven't reprograms for the gears it is not seeing what is expected and will not function properly.
I know alotta LT-1 guys use PCMS FOR LESS.

 

The Hypertech Power Programmer should allow you to change the rear axle ratio in the PCM..... that's one of the few things its actually useful for.

 

the only thing that is concerning to me is that its doing the same thing that it did when i bought the car with the factory gear and had to have the tranny rebuilt. im worried i got shafted on the rebuild

 

Well I would get the programing working correctly first then make that determination , Dont jump the gun just yet

 

ok so what is better haveing a pcm tuned or buying an expensive tuning handheld or laptop software?

 

my hypertech only has a thing to recalibrate the speedometer

 

Do you have a handheld Hypertech tuner that you temporarily attach to the ALDL connector, or a permanent module that plugs into the PCM?

 

To address the other issue you mentioned... if the gears are whining, you may need to adjust the backlash. This is done by adding/removing shims. I'm sure someone here can give you more detailed instructions if you need it.

Also, it's 2.73:1 and 3.42:1, not 2:73 and 3:43. You can leave off the ":1" if you want.

 

its one from summit racing, handheld you plug into the OBD2 port

 

Your 95 has a 16-pin ALDL port, but its not an OBD-II PCM. Still OBD-I.

The Hypertech Power Programmer adjusts for the rear axle ratio. In the instruction book its option F., and as you step through the options its right after the Tire Size, and right before the Shift Point screens.

It calibrates the speedo by allowing you to enter the correct rear axle ratio and the correct tire diameter.

 

ok ive done that and it is still doing the same thing. when you give it any sort of hard gas besides just resting your foot on the pedal it insatntly hits the rev limiter like you put it in neutral

 

if it still just revs slips to the rev limiter and you are not going any faster you have a bad trans and will need to replace or rebuild. Give me a call if you like