Shifting problems when towing - Hemi Truck Club
 
Go Back   Hemi Truck Club > Technical Forums > Drivetrain, Differential and Transmission

Reply
 
Thread Tools Display Modes
 
Old 04-20-2015, 08:17 AM   #1
Junior Member
 
Join Date: Apr 2015
Location: Cleveland
Posts: 7
Shifting problems when towing

I recently purchased a 2004 Ram 1500 5.7 CC with 3.93 rear end. It has only 88,000 miles on it. I tow about a 6500 lb travel trailer. The truck shifts fine when not towing, but is a real problem with the trailer. First problem: when accelerating to enter an expressway, it shifts from 1st to 2nd fine, then stays in 2nd seemingly to long (to about 40 MPH) then downshifts quickly thru 3rd then directly into overdrive. The engines lugs down to about 1700 or 1800 RPM and ruins the additional torque needed to get up to highway speeds. More or less accelerator pressure doesn't keep it in 3rd. Second problem: The engine turns so slow at 60 to 65 MPH towing (about 1800 RPM) that the truck can't maintain speed and constantly falls off cruise and then downshifts. The manual indicates overdrive is supposed to work in both tow and non-tow modes, but I wish there was a way to defeat it when towing. Is this normal for this truck or is there a tranny problem? If so, any thoughts on the possibile points for repair?

RayL is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 04-20-2015, 08:20 AM   #2
Senior Member
 
HemiFun05's Avatar
 
Join Date: Jul 2007
Location: College Station, Texas
Posts: 13,172
Thumbs up

RayL

Someone should be along soon to help you sort out your question .

Welcome to HTC


__________________
HemiFun05
'Doc'
"Christians Aren't Perfect - We Are Forgiven"
HemiFun05 is offline   Reply With Quote
Old 04-20-2015, 09:20 AM   #3
Greg
 
Redtruck-VA's Avatar
 
Join Date: Jan 2011
Location: Virginia
Posts: 18,819
Garage
You should have a OD button on the end of your shift lever. Turn it off and see how it does.
__________________
2003 RCSB, 2wd, "Pro-Street"
6.4L/cog driven V7-Ysi/46rh trans/HTH Truckarm coilover suspension. HP Tuning...

1# 2017 HTC FASTEST HEMI List....
Current 1/4 mile [email protected] (2018)
Current 60' PB 1.351 (2019) mechanical issue for 1/4m

HTC 2018 TOTY

Support vehicle- 2007 QC G56 4x4 diesel
Redtruck-VA is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 04-20-2015, 10:40 AM   #4
Junior Member
 
Join Date: Apr 2015
Location: Cleveland
Posts: 7
Thank you for the reply.

It does have the tow mode button on the shift column, but it doesn't resolve the problem. There is about 300 RPM difference between tow mode (1800 RPM) and non-tow (1500 RPM) settings at about 65 MPH. Still way to little torque for maintaining speed under a tow load or accelerating.
RayL is offline   Reply With Quote
Old 04-20-2015, 11:12 AM   #5
Jim-CO Chapter Dictator
 
RockyMtnXpress's Avatar
 
Join Date: Jan 2010
Location: Salida, Colorado
Posts: 2,290
Have you owned the truck since new?

I am thinking about this comment, "quickly thru 3rd then directly into overdrive" might have the transmission programed into something other than towing or stock. It's a possibility. Not saying it is. I know mine, at 70, will hang in third running 3 grand, with 3:93 gears and with a slight pressure on the pedal. Only when conditions are right (no slope, no headwind, etc.) and backing off the pedal a few hundred will allow the shift to occur. "Tow Haul" is meant to hold each of the primary gears longer to maintain transmission temperature and not allow it to, in a word, use 3rd gear as a stepping stone. More-so when pressure is applied to the gas pedal. When the right conditions occur, it will shift into OD.

Another possible is condition of the transmission. Fluid and filter and when was it last changed?

One thing for sure when towing and the way the transmission is responding, is make sure the tank is filled with 91 octane. For sure you don't need anything less when pulling a load. Just making sure one thing doesn't lead to another.
__________________
RockyMtnXpress is offline   Reply With Quote
Old 04-20-2015, 11:21 AM   #6
Junior Member
 
Join Date: Apr 2015
Location: Cleveland
Posts: 7
Thanks for your insight. I have been using 89 octane. It seems to give a little better mileage than 87. You mentioned the "transmission programming". Can that be reprogrammed? If so how? As I'm not the original owner, I'm not sure if/when the fluids/filter have been changed.
RayL is offline   Reply With Quote
Old 04-20-2015, 12:18 PM   #7
Jim-CO Chapter Dictator
 
RockyMtnXpress's Avatar
 
Join Date: Jan 2010
Location: Salida, Colorado
Posts: 2,290
It can be reprogrammed and (or) verified via dealer service. Ask to see if any DTC has occurred or a possibility reprogramming was done. Tell them you suspect there are problems when you're towing. As I said, "You never can tell" and this will give you a good idea "IF" something was done. I know my docs for my SuperChips Tuner will warn me to never tow haul long distances (or to never at all) with different tunes other than towing. Each tune will change a boatload of things...Including shift points.

THEN

If I was you, I would go through with a transmission service, change rear differential oil, transfer case fluid (if you have one) and front end differential oil (if you have one). Don't mean to be spending someone else's money, but it is way better to know than not. Especially, during the summer heat that will be upon us in another month. Add to that towing...Hmmm?

FYI on octane: My owners manual tells me to use a premium fuel when pulling a heavy load or driving a fully-loaded vehicle when humidity is low and the temperature is high. They also tell us a light spark knock at low engine speeds is not harmful to the 5.7 HEMI. I am not one to worry and resolve such as to exceed their recommendations...just a little. Friendly advice from the stranger from the greater SW where it becomes a hit or miss on gas quality and blends.
__________________
RockyMtnXpress is offline   Reply With Quote
Old 04-20-2015, 12:26 PM   #8
Greg
 
Redtruck-VA's Avatar
 
Join Date: Jan 2011
Location: Virginia
Posts: 18,819
Garage
What size tires are you running?
__________________
2003 RCSB, 2wd, "Pro-Street"
6.4L/cog driven V7-Ysi/46rh trans/HTH Truckarm coilover suspension. HP Tuning...

1# 2017 HTC FASTEST HEMI List....
Current 1/4 mile [email protected] (2018)
Current 60' PB 1.351 (2019) mechanical issue for 1/4m

HTC 2018 TOTY

Support vehicle- 2007 QC G56 4x4 diesel
Redtruck-VA is offline   Reply With Quote
Old 04-20-2015, 12:41 PM   #9
Junior Member
 
Join Date: Apr 2015
Location: Cleveland
Posts: 7
Tire size

It has the factory option 20" tires. Running on recent Goodyear Wranglers P275 60 R20, at the recommended 35 lbs. Trailer tongue weight is about 800 lbs with an Anderson WD, anti-sway hitch. Trailer tires are new Trailer King ST205 75 R15 at 45 lbs.
RayL is offline   Reply With Quote
Old 04-20-2015, 12:46 PM   #10
Greg
 
Redtruck-VA's Avatar
 
Join Date: Jan 2011
Location: Virginia
Posts: 18,819
Garage
Those should be 33" tall and not a problem for the 3:92 gear. How sure are you that you have a 3:92?
__________________
2003 RCSB, 2wd, "Pro-Street"
6.4L/cog driven V7-Ysi/46rh trans/HTH Truckarm coilover suspension. HP Tuning...

1# 2017 HTC FASTEST HEMI List....
Current 1/4 mile [email protected] (2018)
Current 60' PB 1.351 (2019) mechanical issue for 1/4m

HTC 2018 TOTY

Support vehicle- 2007 QC G56 4x4 diesel
Redtruck-VA is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off


» Premium Vendor Showcase
n2 Speed Edge InTune Edge OCPerformance Parts

All times are GMT -6. The time now is 05:13 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.