4l80e shift points - Diesel Place : Chevrolet and GMC Diesel Truck Forums
 
Home Forum Market Place Garage Lounge (0) Tuning Library DTC Tool Register Vendors
Go Back   Diesel Place : Chevrolet and GMC Diesel Truck Forums > GM Transmissions > 4L80/85E Transmissions. 6L90 Transmission
Register FAQ Forum Rules My Replies My Threads Mark Forums Read Auto EscrowAuto LoansInsurance

4L80/85E Transmissions. 6L90 Transmission Discuss the 4L80/85E transmissions found in the 6.2/6.5L equipped vehicles and Duramax equipped vans. 6L90 discussion.

DieselPlace.com is the premier Duramax Diesel Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 10-20-2010, 12:12 AM   #1 (permalink)
wholzgrefe89
Diesel Enthusiast
 
Join Date: Oct 2010
Posts: 4
iTrader Score: 0 reviews

4l80e shift points

hey i have a 1993 k2500 pickup with 6.2l diesel and a 4l80e trans and it seems like the engine reves up pretty high before it shifts idk if this is normal or not. From first to second it hits pretty hard when it shifts but from second to third and third to OD it shifts fine it just revs up high the fluid looks clean idk about the filter i just got the truck about a week ago.


thanks

Last edited by wholzgrefe89; 10-20-2010 at 12:13 AM.
Offline  
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 10-20-2010, 03:29 AM   #2 (permalink)
bigblock72
Diesel Fanatic
 
Join Date: Nov 2008
Location: Utah
Posts: 73
iTrader Score: 0 reviews

Quote:
Originally Posted by wholzgrefe89 View Post
hey i have a 1993 k2500 pickup with 6.2l diesel and a 4l80e trans and it seems like the engine reves up pretty high before it shifts idk if this is normal or not. From first to second it hits pretty hard when it shifts but from second to third and third to OD it shifts fine it just revs up high the fluid looks clean idk about the filter i just got the truck about a week ago.


thanks


Shift points are determined by the programming in the transmission control module, so if it shifts it's normal.

The hard shift into second is a little abnormal and may be a sign of a broken accumulator spring but isn't anything to worry about until more serious symptoms show up.
__________________
94 GMC C3500 dually w/whippled 7.4l

09 Kodiak D-max C5500/Road Warrior motorhome

01 GMC Yukon XL 8.1

Just make it big, make it a GMC and it's all good
Offline   Reply With Quote Quick reply to this message
Old 10-20-2010, 09:15 AM   #3 (permalink)
wholzgrefe89
Diesel Enthusiast
 
Join Date: Oct 2010
Posts: 4
iTrader Score: 0 reviews

Alrighty I'm gonna try the Lucas oil transmission stuff when I change my filter and see if it helps
And I noticed this morning when I drove to work it didn't rev up high before it shifted
Offline   Reply With Quote Quick reply to this message
Old 10-22-2010, 06:40 AM   #4 (permalink)
GenBiltstein
Diesel Master
 
GenBiltstein's Avatar
 
Join Date: Nov 2007
Location: Prince George, Virginia
Posts: 1,879
iTrader Score: 0 reviews

Armed Forces Club Member

The shift points are determined by a few factors. One being the Throttle position sensor on your truck.
Before you do anything else I would check into the TPS (as it is called fo9r short) for a correct adjustment.
A misadjusted TPS can cause erratic shifting.
Offline   Reply With Quote Quick reply to this message
Old 11-26-2010, 04:06 PM   #5 (permalink)
wholzgrefe89
Diesel Enthusiast
 
Join Date: Oct 2010
Posts: 4
iTrader Score: 0 reviews

well it stopped reving high but now it shifts really fast even if i floor it it short shifts and when im on the highway when i go to pass a car it dosent down shift it seems like it bogs a little and takes along time to build speed whats going on with that?

thanks
Offline   Reply With Quote Quick reply to this message
Old 11-26-2010, 04:31 PM   #6 (permalink)
GenBiltstein
Diesel Master
 
GenBiltstein's Avatar
 
Join Date: Nov 2007
Location: Prince George, Virginia
Posts: 1,879
iTrader Score: 0 reviews

Armed Forces Club Member

The TPS needs to be adjusted correctly.

Find out what you or someone else did before the transmission went to late first shifting.
Offline   Reply With Quote Quick reply to this message
Old 11-26-2010, 11:38 PM   #7 (permalink)
turbonator
Frieghtliner the bull....
 
turbonator's Avatar
 
Join Date: Oct 2009
Location: lac superieur, quebec
Posts: 7,103
iTrader Score: 22 reviews

Old School Oil Burners (Old SOBs) Member

Quebec/Labrador Diesel Place Chapter Member

It seems like the TPS to me to, it might be starting to have ''dead spots'' in it and giving bad voltages to TCM.
__________________
1992 gmc 3500 drw, rclb..... very, very full of goodies
1986 jetta IDITI, some goodies(apart for modifications)
1990 gmc 3+3 crew, 2WD, 6.2l N/A... soon to be ATS charged
acolytes of the "aggressive buddist's" principles since march 13th 2014
building power, "Sanford and Son style"

under development:
Testing of ATS 6.2l turbo kit
-center mount turbo kit with tubular manifolds( almost finished)....
and much more.....
Jeff & jim....

Offline   Reply With Quote Quick reply to this message
Old 11-27-2010, 04:48 AM   #8 (permalink)
GenBiltstein
Diesel Master
 
GenBiltstein's Avatar
 
Join Date: Nov 2007
Location: Prince George, Virginia
Posts: 1,879
iTrader Score: 0 reviews

Armed Forces Club Member

To check for dead spots.
Ohms on a multimeter. Find the pin taking live voltage in from the computer. Find the resisted pin that sends information to the computer. Easily done. Pin A and Pin B
Set the multimeter on resistance. Handthrottle it slowly you will see a graduated decrease in resistance. There is one dead spot left in the TPS on purpose. This is to downshift.
Also check for live voltage coming into Pin A
Check for a solid ground signal out of Pin C

Just for good insurance
Take the same multimeter and check every living ground terminal you have. Anything above .02 take apart the ground terminal and clean it.
That multimeter is a labor saver and prevents you from guessing which grounding terminal is unserviceable and prevents you from reaching those hard to get to terminals that might be serviceable anyway.
Offline   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 Diesel Place : Chevrolet and GMC Diesel Truck Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

PLEASE READ! You must check your email inbox for the confirmation link to complete registration. Please check your spam box if you do not see the email in your inbox.

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:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Shift points A_T_Ver Drag Racing 13 12-26-2008 01:00 PM
Changing shift points on '95 4L80E? and other questions D350Diesel Drivetrain - 2001 - 2010 4 05-17-2007 10:05 AM
shift points for best MPG sstd595 6.5L Diesel Engine 14 01-08-2007 11:53 AM
Shift points ccii42104 Allison OEM 1 11-10-2006 01:55 AM


All times are GMT -4. The time now is 01:54 PM.


Shoutbox provided by vBShout v6.2.1 (Lite) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
© AutoGuide

SEO by vBSEO 3.6.0