04.5 Tow Haul Mode

[TJMIV]

Have a friend with 04. 5 ,3500,4x4, Quad-Cab,Auto,& 4. 10 gears- Just bought a toy hauler fifth-wheel that he says weighs 11,500 empty. His concern is should he pull this thing in tow-haul mode, says in tow-haul mode on, his truck it will not shift into over-drive & turn`s about 2,800 rpm`s @ 70 mph. He want`s to know if this is going to hurt anything other than fuel economy? With tow-haul off @ 70 mph say`s it turn`s about 2100 rpm`s. Truck is stock, he want`s some feedback before before tearing something up. Thanks In Advance.

 

[DPKetchum]

It should shift into o/d just at a higher rpm but not 2800. If thats the case theres a issue.

 

[JimBob24]

I had an 04. 5 and I was thinking that the tow-haul mode is basically an o/d lock-out and will not shift into o/d at any speed with the tow-haul engaged. It is not a 2 selection unit like my 06. I pulled about 11K with the 04. 5 and left the tow-haul off when pulling on fairly level roads where the trans did not shift in/out of o/d a lot. When in stop & go traffic and hilly country I turned the tow-haul on.



Jim

 

[troll3193]

I had that year, and the tow/haul does not allow it to go into OD. that came in in 05...



I would run in tow/haul till I got about 50-55 then would turn it off. .



Bryan

 

[DPKetchum]

Tow haul and O/D lockout are two differant things. The o/d lockout does just that,locks out 4th(o/d). It does not change the valving in the trans for towing(06 does BOTH) Tow/haul changes when trans shifts(all 4 gears/o/d still works) and the valving in the valve body to hold shifts longer etc. 03/04 o/d lockout. 05 tow/haul no o/d lockout. 06 does both tow haul and o/d lockout if you want it to. I was wrong on the issue as 04. 5 did not have tow/haul,only o/d lockout.

 

[GColeman]

In the 04. 5, Tow Haul locks out OD and changes shift points. With 4:11 gearing pulling that kind of load, use Tow Haul at lower speads and steep grades. On flat pulls at freeway speeds, click off the TH and let the OD engage. 2100 rpm should give him a nice cruise. If road conditions (grade, wind, etc) cause him to lose speed, just disengage TH until conditions allow the use of OD again.

 

[DPKetchum]

If it locks out O/D its not tow/haul. Its just O/D lockout or for years called O/D OFF. 05 had Tow/Haul and no way stock to lock out O/D.

 

[GColeman]

Well... ... ... ... . when I push the button, the words "Tow Haul" appear and the shift points are different that when it is not in Tow Haul. Don't know what to tell you DPKetchum.



TJMIV... ... ..... Tell your friend to push the button and it will give him what he needs when he needs it. It's time for a beer!

 

[JimBob24]

Might want to look at the service manual for the 04. According to the manual the tow-haul only locks out o/d.

 

[WHazelwood]

I have the 04. 5 and it works the same as the 05. 04,5 is when they changed it, I think. Lke was said before, as long as the transmission is not hunting, I leave it off, when I start up a grade, I'll push TH on. No problems so far with 60K.

 

[GColeman]

I have the 04. 5 and it works the same as the 05. 04,5 is when they changed it, I think. Lke was said before, as long as the transmission is not hunting, I leave it off, when I start up a grade, I'll push TH on. No problems so far with 60K.

That was my understanding too. But, I'm not a transmission guy. I do exactly as you and I have pulled some heavy loads with no problems so far at 50K.

 

[TJMIV]

I thank all of you for your time & replies, sorry it took me so long to get back to the computer. I will print this info. & pass it along to my friend & let him make a well informed decision. I did`nt know what to tell him because I had not owned an auto until this 07. Thanks a bunch, TJMIV

 

[RMarkey]

04. 5 says tow/haul, but it locks out OD.

 

[RMalone]

My 04. 5 also calls it "tow/haul". It is ONLY an od lockout on mine, I have taken it to 3400rpm with od locked out and it never shifted. The tow/haul or od lockout setting does not change shift point at all in my truck. The only thing that changes any shift points is manually dropping the lever into 2nd and then the 1-2 shift occurs at a higher rpm. My truck is an early 04. 5 so there may have been some programming changes on trucks made late in the 04. 5 cycle.

 

[WhiteSheep]

Everyone is right (almost)

On the early 4. 5s the tow/haul button is simply an O/D lockout. Later in the year, the tow/haul feature was "upgraded" to allow O/D and increase the RPM shift points. This is essentially the 05 48RE. This is why some of you with 4. 5s have O/D with TH and some don't. Check when your truck was built. My is an early 4. 5 and TH definetly does not allow O/D. I like it this way.

 

[DPKetchum]

Thats what I thought I said. Maybe I wasn't clear enough.

 

[FParlee]

Another twist, 2nd gear lock up.

I have an early 04. 5 with 3. 73 gears pulling a 14K 5th wheel. As the gentlemen have said, the early units just lock-out overdrive. My problem is getting the torque converter to lock to keep the trans temp down. In low speed driving I start out in 2nd gear. If you leave the gear selector in 2nd, it WILL lock the torque converter at about 20 to 25 mph. Once its locked, I can run it up to about 45 mph, back off the pedal, and put the selector in drive with the overdrive locked out. (I back off the pedal just to get a smooth shift). For my truck this is in the range to get the torque converter to lock in 3rd. Then once I'm over 50 mph I can get it to lock up in over drive.



I only do all this to keep the torque converter locked as much as possible. When unlocked and under heavy torque on hills or pulling away from lights I can watch the trans temp gauge going up. The sending unit is mounted in the pan. (Extra deep Hytec unit)



I have 80K miles and the trans still feels strong. The only time the truch has let me down was a leak in number 6 injector line on vacation in the mountains of West Virginia. The local Dodge dealer, Moore Auto Group, took the parts off a new truck on the lot to get me going on a Saturday morning. You can't ask for more than that...



Let me know what you thing of the 2nd gear lock up trick!



Fred Parlee

 

[RMalone]

I have seen my truck lock the t. c in second with the lever in the 2 position. One other interesting thing I have seen is dropping the lever into 2 at about 30mph (in an effort to keep the t. c locked), sometimes the truck just stays in 3rd until the normal speed (with lever in drive) that 3rd releases to 1st. Other times the truck will slam into 2nd locked, which is pretty cool, problem is, the truck wont shift from 2nd to 3rd until you shut 'er down and fire it back up.



My truck is quite variable as to when 3rd locks up. Sometimes it happens right at the 2/3 shift, other times it doesn't happen until almost 50mph (that is the speed I have the DTT smart box set for the 3/4 shift).