Transmissions and Drivetrain Need help with your trans? Problems with your axle?

Can you adjust 700r4 shift points?

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Old Aug 29, 2004 | 12:17 AM
  #1  
phishfud's Avatar
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From: Pittsburgh
Car: 88 GTA
Engine: 350
Transmission: Auto
Can you adjust 700r4 shift points?

The trans in my GTA shifts fine, nice and tight. It seems that the 1st doesnt wind out much and it into second very quickly. Any way to change this, or is this normal. this is in an 88 GTA if that matters. thanks.

Terry
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Old Aug 29, 2004 | 12:40 AM
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Cadillac's Avatar
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From: Marietta, GA
Car: '91 Firebird Convertible
Engine: 305 TBI (LO3)
Transmission: 700r4, Vette Servo
Axle/Gears: 3.27 9 Bolt, PBR disks
Re: Can you adjust 700r4 shift points?

Originally posted by phishfud
The trans in my GTA shifts fine, nice and tight. It seems that the 1st doesnt wind out much and it into second very quickly. Any way to change this, or is this normal. this is in an 88 GTA if that matters. thanks.

Terry
I'm guessing but been exposed to transission issues with GM cars for over 20 years.

You can adjust the transmission shift points. To be specific however, I cannot be. I know it's an adjustment with the vacuum system that is working with the throttle.

I would not be surprised to hear that I am totally wrong but someone here will follow me and either semi-confirm what I recall or blow me out of the water and back to the "Auto Detailing and Appearance" board.

hehe

~C
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Old Aug 29, 2004 | 07:36 AM
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From: new york city
there are two hydraulic signals that feed information to the valve body to provide input (three if you count the gear selector)to be used in shift strategy by the valve valve bod. first is the vehicle speed signal ,also called governor pressure,which is a hydraulic signal that is regulated between roughly 90 and 200 psi depending on governor speed/ output shaft speed and is sent to the shift valves to push them open and initiate ratio changes .the second is engine load signal,also called modulated throttle valve pressure,which is a hydraulic signal that varies between 0 and 90 psi depending on throttle angle.this pressure is fed to the tv up and down valves ,reregulated ,and then sent to the shift tv valves to either assist the shift valves and a precalibrated valve land diameter and shift tv valve spring against governor pressure or delay it.what this does is allow the transmission to either remain in a particular ratio longer,or shorter based on engine load and throttle angle.in your case it sounds like the tension of the 1/2 shift is too soft resulting in too quick an upshift .a stiffer spring should help .this a very common complaint with the 700r4 transmission.using a slightly lighter primary weight on one side of the governor will also help if you opt not to remove the valve body.

Last edited by chris718; Aug 29, 2004 at 02:14 PM.
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Old Aug 29, 2004 | 08:48 AM
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phishfud's Avatar
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From: Pittsburgh
Car: 88 GTA
Engine: 350
Transmission: Auto
Believe it or bot, that makes sense, mostly, hehe. Question is, where can I get a stiffer spring nd how hard to install? I have dropped valve bodies before, so not a problem, but I have no idea where to even get a stiffer spring. Thanks.
Terry
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Old Aug 29, 2004 | 08:51 AM
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send me the old one and ill send you another.
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Old Sep 2, 2004 | 12:31 AM
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From: Winnipeg,MB
Car: 1991 Camaro Z28
Engine: 350 L98
Transmission: 700R4
Check this kit out
http://www.fairbanksperformance.com/...nt_package.htm
It has different sets of springs and weights incase you want to change your shift points in the future. Just look at their site for a local distributors.
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