01 7.3 auto shift too high rpm - Diesel Truck Forum - TheDieselGarage.com
Thread Details Posted by Lunendan, this thread has received 2 replies and been viewed 8499 times.

LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 11-12-2013, 01:28 PM Thread Starter
Junior Member
Join Date: Mar 2008
Posts: 20
Points: 8,513
Thanks: 0
Thanked 1 Time in 1 Post
01 7.3 auto shift too high rpm

I have a stock 01 7.3. I had the trans rebuilt recently by a local reputable trans shop. I went with a heavier duty than stock torque converter and told him I had a 30' camper and may add a plow(he asked these questions) and built it accordingly to be stronger than stock. The truck runs great and has no problems.

The tranny works and shifts well...but...when I get on the highway, which from my exit there is no phase in lane, you just jump right out into traffic, I have to basically floor it to get out of the way.

When I stomp on it to get moving, the engine revs all the way to 3200/redline before it shifts, same for all gears. So basically the power falls flat on its face and acceleration is terrible. All other driving conditions the truck shifts fine and is great. Only when I floor it. I replaced the speed sensor in the rear end and it made no difference. The tranny before it quit, behaved in exactly the same manner. It actually accelerates faster at 3/4 throttle because it shifts earlier.

Does anyone know why this is happening and what I can do to have it shift at about 2800rpm at full throttle?

I have not had time to go back to the tranny shop yet. But I wanted some useful background info from you guys before I go, in case there is something I can do about it first.

Thanks, -Dan
Lunendan is offline  
Sponsored Links
post #2 of 3 (permalink) Old 11-12-2013, 04:54 PM Thread Starter
Junior Member
Join Date: Mar 2008
Posts: 20
Points: 8,513
Thanks: 0
Thanked 1 Time in 1 Post
I think I should have been a little more specific. It does not rev to 3200 before the truck moves. It takes off just fine and pulls well through first gear, but where I think it should be shifting to 2nd at about 2800, it revs right past that, power falls off dramatically, hits 2nd gear at 3200 and rpm drops to about 2700, tries to pull again but is already at the end of the power curve and power is falling off again up to 3200 before it hits 3rd. So as far as trying to accelerate quickly into traffic, it does not work so well. Verses my old 99 7.3 6-spd that I could shift out at 2800, drop to 2300, and pull hard again through the power curve.

How do I fix this? Does a tuner allow you to select specific shift points?
Lunendan is offline  
post #3 of 3 (permalink) Old 11-12-2013, 07:19 PM
Stuck in Commiefornia...
IdahoF350's Avatar
Join Date: Dec 2008
Location: Clearfield, Utah
Posts: 1,296
Points: 81,328
Thanks: 102
Thanked 447 Times in 315 Posts
It could be a number of things but being an electronically controlled transmission it's relying upon the load and throttle input from the driver to determine the shift points if you have a bad map sensor a bad throttle pedal or an issue in the tuning that you're running if you're running to any of those things could be the source of your issue.

I just tuned my truck, an early 1999 7.3, because the shift from third to overdrive wasn't occurring until 55 to 60 mph and should've been occurring at 40 to 45 under the amount of throttle input that I was giving the problem was exclusively tuning issue there was nothing mechanically wrong with my truck. Running a canned SCT performance tune completely resolved the shipping issues for my truck and it now shifts at the desired 40 to 45 mph under light throttle the way I want it to.

Sent from AutoGuide.com Free App

The Current Truck (Oct-2013 to Present):
1999 (Early) F-350 Lariat, CCLB, SRW, Black/Tan

7.3L Powerstroke, 4R100, 4x4, 3.73, 37x13.50-18s, '05 Axle Swap, 6" Fabtech lift, GTP38 "D66" turbo upgrade, SCT 4-position chip with custom tuning by me, Straight Piped 4" down pipe through 5" dual stacks, N-Fab full length triple steps, Pro-Tech cab guard and tool box, louvered 5th wheel gate, Hella 500 Fog and Driving lamps, much more to come...
The one I'll miss, (Mar-2009 to Jan-2014):
2000 Excursion XLT 4x4

6.8L V-10, 4R100, 4.30, 285/75-18, 271whp / 388wtq
The one I won't, (Jul-2005 to Sep-2012):
2005 F-350 XLT, CCLB, SRW, 4x4 FX4

6.0L PSD, ZF-6S650, 3.73, 35x12.5-18, 4.5" Lift
IdahoF350 is offline  

Quick Reply

Register Now

In order to be able to post messages on the Diesel Truck Forum - TheDieselGarage.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
Speedometer not working right and very high RPM 97CumminsTurboDiesel 5.9L Cummins 12 Valve (1994-1998.5) 5 10-18-2010 10:56 AM
rpm not going high enough exoticsrnw 5.9L Cummins 12 Valve (1994-1998.5) 3 03-07-2008 05:41 PM
whats too high of RPM popeye 7.3L and 6.9 IDI (Pre 1994) 14 09-19-2006 09:19 PM
High RPM's on new IT 4300 Dagwood_55 Medium and Heavy Duty 4 06-19-2006 05:03 PM
Squeeking Noise At High Rpm F250SMOKER 2003-2007 6.0L Power Stroke 8 04-25-2006 03:49 PM

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

For the best viewing experience please update your browser to Google Chrome