2002 Trailblazer transmission do i need to worry? - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum



Welcome Enthusiast! If you already own a Chevy TrailBlazer or GMC Envoy or perhaps thinking of purchasing such a vehicle, then you have come to the best TrailBlazer and Envoy site on the net! Rainier, Bravada, Ascender, and 9-7x owners welcome too!

You are currently viewing our site as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to search and post topics, communicate privately with other members, respond to polls, upload content, and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
Join Today!
Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2002 - 2009 TrailBlazer/Envoy Tech > 02-09 Vortec 4.2L I-6 Engine and Drivetrain > Transmission Mods

Transmission Mods Performance Transmission Modifications

TrailVoy.com is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools
  #1  
Old 04-20-2019, 06:22 AM
sky_blazer02's Avatar
sky_blazer02 sky_blazer02 is offline
Junior Member
 
2002 Chevy TrailBlazer LTZ
Black Granite Metallic 4.2L I6 4X4
Join Date: Apr 2019
Location: Michigan
Posts: 12
2002 Trailblazer transmission do i need to worry?

hello everyone this is my first post here. i recently picked up my first Trailblazer 4x4 LTZ 2002. the vehicle runs great and rides great, but this being my first Trailblazer i have nothing else to compare to. my transmission started acting funny, still getting all my gears but it just seems like the shift points are late. on a cold engine its more noticeable like almost 3k before a shift. at normal operating temp i can see 2k on a shift which feels normal with easy throttle, but if i give heavy throttle its shifting at 2500, this is operating temp. also others have said feels like overdrive is coming in late. on heavy acceleration im reaching 60 MPH and shes still shifting, this does not feel normal. i checked the fluid level and its full and doesn't smell burnt. i thought about taking her in to have the fluid/filter changed, but i keep reading about shift solenoids and them being common problems. i have no SES light and the transmission pulls strong so IDK what to think if im looking at a rebuild in the future. everything else on this vehicle works great AC, heat, 4x4, awesome LED headlight mod very little rust for a Michigan 17yr old SUV thats why i wanna make this work. any thoughts?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 04-20-2019, 08:55 AM
NJTB04 NJTB04 is offline
Member
 
2004 Chevy TrailBlazer LS
Pewter Metallic 4.2L I6 4X4
Join Date: Aug 2012
Location: Edison, NJ
Posts: 269
As you said, try changing the trans fluid with Dex 6.
Quick and dirty, pull the passenger side trans line from the radiator, put a rubber hose on it to a oil drain pan, start the car until the fluid coming out sputters. Then refill and drive.
If the trans filter is partially clogged it won't help anything, so take it FWIW.
If you have access to a Tech2, you can change the shift points, assuming there is no internal damage.
Reply With Quote Quick reply to this message
  #3  
Old 04-20-2019, 12:02 PM
EnvoyBoy2004's Avatar
EnvoyBoy2004 EnvoyBoy2004 is offline
TrailVoy Alumni
 
2004 GMC Envoy SLT
Graphite Metallic 4.2L I6 4X4
Join Date: Sep 2014
Location: NY
Posts: 2,022
It may pay to see if the Intake Air Temperature (IAT) sensor is working correctly. If it is feeding incorrect temp info to the PCM, the shift point will be late because it thinks the outside air is still cold. Also make sure that the ambient temperature is indicating correctly either on your inside mirror or on the HVAC panel (depending which system you have).
Reply With Quote Quick reply to this message
 
  #4  
Old 04-20-2019, 05:19 PM
miketexas miketexas is offline
Member
 
2003 Chevy TrailBlazer LS
Black 4.2L I6 2WD
Join Date: Feb 2018
Location: TX
Posts: 435
Quote:
Originally Posted by sky_blazer02 View Post
hello everyone this is my first post here. i recently picked up my first Trailblazer 4x4 LTZ 2002. the vehicle runs great and rides great, but this being my first Trailblazer i have nothing else to compare to. my transmission started acting funny, still getting all my gears but it just seems like the shift points are late. on a cold engine its more noticeable like almost 3k before a shift. at normal operating temp i can see 2k on a shift which feels normal with easy throttle, but if i give heavy throttle its shifting at 2500, this is operating temp. also others have said feels like overdrive is coming in late. on heavy acceleration im reaching 60 MPH and shes still shifting, this does not feel normal. i checked the fluid level and its full and doesn't smell burnt. i thought about taking her in to have the fluid/filter changed, but i keep reading about shift solenoids and them being common problems. i have no SES light and the transmission pulls strong so IDK what to think if im looking at a rebuild in the future. everything else on this vehicle works great AC, heat, 4x4, awesome LED headlight mod very little rust for a Michigan 17yr old SUV thats why i wanna make this work. any thoughts?
Changing the fluid will not have any effect on it. If the shift solenoid(s) were bad the trans would take off in third gear all the time. it is possible one is leaking a little, but it's rare. You might suspect the TPS but at this point it's all guess work. One easy thing to do is clear the battery then reconnect it and drive it around easy and let it relearn and see what happens.
Reply With Quote Quick reply to this message
  #5  
Old 04-20-2019, 09:45 PM
sky_blazer02's Avatar
sky_blazer02 sky_blazer02 is offline
Junior Member
 
2002 Chevy TrailBlazer LTZ
Black Granite Metallic 4.2L I6 4X4
Join Date: Apr 2019
Location: Michigan
Posts: 12
Quote:
Originally Posted by miketexas View Post
Changing the fluid will not have any effect on it. If the shift solenoid(s) were bad the trans would take off in third gear all the time. it is possible one is leaking a little, but it's rare. You might suspect the TPS but at this point it's all guess work. One easy thing to do is clear the battery then reconnect it and drive it around easy and let it relearn and see what happens.
if the TPS was bad wouldnt i get a code? ill try disconnecting the battery, see what happens
__________________
2008 Pontiac G5 5 speed-2002 Chevrolet Trailblazer LTZ 4x4-1999 Oldsmobile Bravada AWD-1986 Pontiac Trans Am 5.0
Reply With Quote Quick reply to this message
  #6  
Old 04-21-2019, 09:20 AM
miketexas miketexas is offline
Member
 
2003 Chevy TrailBlazer LS
Black 4.2L I6 2WD
Join Date: Feb 2018
Location: TX
Posts: 435
Quote:
Originally Posted by sky_blazer02 View Post
if the TPS was bad wouldnt i get a code? ill try disconnecting the battery, see what happens
You would usually get a code yes, but in the real world things don't always work like we expect.
Reply With Quote Quick reply to this message
  #7  
Old 04-21-2019, 10:03 AM
sky_blazer02's Avatar
sky_blazer02 sky_blazer02 is offline
Junior Member
 
2002 Chevy TrailBlazer LTZ
Black Granite Metallic 4.2L I6 4X4
Join Date: Apr 2019
Location: Michigan
Posts: 12
Quote:
Originally Posted by miketexas View Post
You would usually get a code yes, but in the real world things don't always work like we expect.
how do i test the TPS to see if it working correctly?
__________________
2008 Pontiac G5 5 speed-2002 Chevrolet Trailblazer LTZ 4x4-1999 Oldsmobile Bravada AWD-1986 Pontiac Trans Am 5.0
Reply With Quote Quick reply to this message
  #8  
Old 04-21-2019, 04:12 PM
miketexas miketexas is offline
Member
 
2003 Chevy TrailBlazer LS
Black 4.2L I6 2WD
Join Date: Feb 2018
Location: TX
Posts: 435
Quote:
Originally Posted by sky_blazer02 View Post
how do i test the TPS to see if it working correctly?
The only way I know to test them is to use a digital oscilloscope. I have one and they do work, but you can get a good idea from reading the voltage coming from the tps with a scan tool. usually at closed throttle it will read about .5 volts or so up to about 4.5 or so at wide open throttle. The voltage should rise steadily but not go up and down. What did clearing the battery do? Anything?
Reply With Quote Quick reply to this message
  #9  
Old 04-21-2019, 04:52 PM
sky_blazer02's Avatar
sky_blazer02 sky_blazer02 is offline
Junior Member
 
2002 Chevy TrailBlazer LTZ
Black Granite Metallic 4.2L I6 4X4
Join Date: Apr 2019
Location: Michigan
Posts: 12
Quote:
Originally Posted by miketexas View Post
The only way I know to test them is to use a digital oscilloscope. I have one and they do work, but you can get a good idea from reading the voltage coming from the tps with a scan tool. usually at closed throttle it will read about .5 volts or so up to about 4.5 or so at wide open throttle. The voltage should rise steadily but not go up and down. What did clearing the battery do? Anything?
i do have a scanner that displays live data and this is what the throttle position said at idle

i noticed the TPS come built in the throttle bodies so if i have to do it i gues i have to replace the whole throttle body?
Attached Thumbnails
Click image for larger version

Name:	IMG_20190421_164828[1].jpg‎
Views:	17
Size:	1.24 MB
ID:	38013  
__________________
2008 Pontiac G5 5 speed-2002 Chevrolet Trailblazer LTZ 4x4-1999 Oldsmobile Bravada AWD-1986 Pontiac Trans Am 5.0
Reply With Quote Quick reply to this message
  #10  
Old 04-21-2019, 07:44 PM
miketexas miketexas is offline
Member
 
2003 Chevy TrailBlazer LS
Black 4.2L I6 2WD
Join Date: Feb 2018
Location: TX
Posts: 435
Quote:
Originally Posted by sky_blazer02 View Post
i do have a scanner that displays live data and this is what the throttle position said at idle

i noticed the TPS come built in the throttle bodies so if i have to do it i gues i have to replace the whole throttle body?
On that model I believe you can change just the TPS. So, did clearing the battery have any effect?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum forums, you must first register.

Please enter your desired user name, your email address and other required details in the form below.
(Only letters, numbers, dashes and underscores are permitted for user names)
The user name that you choose is permanent and can never be changed.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Location
Where you live (ex: Philadephia, PA)
Vehicle Year
Choose your year
Or enter your choice here:
Vehicle Color
Choose your factory color (Custom, Not Listed & Two-Tones; Use Text Field Below)
Or enter your choice here:
Vehicle Make
Choose your make
Or enter your choice here:
Vehicle Model
Choose your model
Or enter your choice here:
Vehicle Engine
Choose your engine
Vehicle Drivetrain
Choose your vehicle drivetrain
Security Question
Fill in the blanks: Tra___oy
Insurance
Please select your insurance company (Optional)

Log-in



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
2002 XL's Envoy & Trailblazer rbagley Introductions 1 10-16-2014 07:40 PM
2002 Trailblazer AC lines different from all other years?!?!? Jeremy29 General 0 08-24-2014 01:59 AM
2002 trailblazer transmission removal from underneath the bottom of truck jrq71071 Transmission Mods 1 06-07-2014 12:05 PM
Just got a 2002 Trailblazer...transmission question mrdctaylor General 9 05-13-2014 10:51 PM
2002 LTZ Trailblazer problems: trans slip, PS leak, front end noise aliriano1 OEM Issues 3 08-02-2009 11:21 PM


» Sponsors

Advertising Info

All times are GMT -4. The time now is 10:19 AM.


Chevy TrailBlazer and GMC Envoy Enthusiasts - Copyright 2004 - 2009 All Rights Reserved.
All trademarks referenced herein are property of their respective owners.
RSS Feed