Hi everyone, I don't own a truck yet and am completely new here. I'm in the process of selecting a truck to tow a fifth wheel. Today I drove a Dodge Cummins 350 2005. There was a tow-haul button on it and I forgot to ask the dealer about it! They are closed now. Could someone please tell me what this does? I was told that the Chevy Duramax Allison has this button, but the Dodge doesn't, so I am a little confused.

Thanks, Eileen

 

Eileen, it used to lock the transmission out of overdrive, but now for 05 it informs the transmission computer that you're hauling heavy and I beleive it changes the shift patterns... not sure if that helps much.

 

Thank you. I'm not sure I know what that means! Eileen

 

Well hi Eileeneh,

You found us on one of the best sites on the web. Welcome. Good bunch of people on here - - well, there are a couple wierd ones. And you sure can't go wrong looking really hard at the Dodge trucks. They drive super and are extremely dependable.

The Tow/haul mode is something new on the Dodge tranny - - the tranny has been highly updated to handle the high torque and HP of the engines and is supposed to be extremely reliable. Hopefully one of the guys will kick in some info that either has one or can answer the question with some degree of knowledge.

Now, go get yourself a nice Dodge and hang around a while.


FiverBob

 

Eilleen , The tow hall on the 2004s raised the shft patterns to a higher rpm to assist in getting a big load going easier.,and it also locked out 4th gear or overdrive.
The tow hall on the 2005 just raises the shift points but DOESNT lock out 4th gear
To save the trans from gear hunting, automatic trans have had a overdrive lockout for years, even on cars, for hilly or mountianes driving. We'll see how this 2005 works out. when you get a big trailer behind there and then pull in hilly country, and the trans starts shifting back and forth between 3rd and 4th and you cant lock out 4th???? Cant beat the Cummins though.

 

Can't you simply put the gear selector lever in Drive to effectively lockout Overdrive? Or am I missing something?

 

The gear selector should already be in Drive. Maybe you mean shift into 2nd to lock out OD? This would probably be too low a gear for most terrain, but I guess in some steep grades with a real heavy load it would be OK.

 

On most Chevys that I've driven, their gear selector shows P-R-N-OD-D-2-1.
The Dodge doesn't have a gear selector position for OD.
If you don't want to be in OD, there is a button on the dash or the end of the gear selector that when pushed turns on an indicator light showing that OD is now locked out.

 

Shovelhead, NOT on the 2005s , I repeat you cant lock out overdrive on the 2005s the push button on the shifter puts you in tow haul which raises shift points but does NOT lock out overdrive!! On the 2004s the pushbutton or towhaul raised shift points AND LOCKED OUT OVERDRIVE. YOU CANNOT lockout overdrive on these 2005s and I question the reasoning behind that.

 

Thanks everyone. I still don't understand the ramifications for the driver of not being able to lock out overdrive. How does that affect the person driving?

Thanks, Eileen

 

HMMMM.... looks like another case of "newer ain't necessarily better".

Thanks for the update.

Ed

 

Eilleen,
If you cant lockout overdrive, when you hit the grade that overdrive cant pull trans will shift back into 3rd. and up you go --Untill you hit the level spot or back off throttle for a switchback . Then the trans will upshift to overdrive , and as soon as you start the grade again it'll shift back to 3rd . this is gear hunting and is hard on the trans. Where if you can lockout overdrive,you will eliminate this unwanted upshift to overdrive. Now if the grade is steep enough that you cant pull in 3rd you can pull shift lever down into 2nd and then you do in fact lockout 3rd and 4th. 4th being overdrive on this truck. and you will take that 12000 lb trailer up a 10% grade with ease at 30 mph.. But if you wish to run 50 in third you cant lockout 4th.
Now as anyone knows that has run the mountains these steap grades are not a steady , streight grade. They have short level spots, and when you let up throttle on these level spots to maintain your 50 mph trans will upshift . Or when you let up throttle to make a switchback or a curve trans will want to upshift. This all depends on road grade and speed etc. But the fact is there that on the 2005s you cant lock out the overdrive and one should know this going into a purchase. Now the dealers try to tell me that this new 2005 48re is so smart it'll stay in the right gear all the time???????????? That sounds like someone that has never pulled in the mountains.

 

Thanks. That helps me have a clearer picture of what actually happens (although it's still theoretical to me, having never experienced it). Is there a solution to that problem? It doesn't make sense for me to buy a used one (they are same or more than new ones).

Thanks, Eileen

 

PS--It seems to me that this is exactly the problem that Bob, who posts here, thinks a 4.10 rear axle will help to resolve (hope I got that right!). But unfortunately I'm not in the mountains most of the time. . . Eileen

 

Best solution, if you are going to tow heavy. Buy the six speed manual and ether 3:73 or 4:10 gears. Then you will not have a problem . Just my 0.02