How Does Tow/Haul Work?

[trqmnstr]

I thought that Tow/Haul mode just held the gears longer and still used O/D. I tried my Tow/Haul for the first time the other day and it performed as I thought but it wouldn't shift into O/D. What is it really supposed to do?

 

[BHolm]

The '03 and early '04 trucks should have an OD off button. I don't think Tow/Haul came along until 04. 5. This is the second post I have seen like this though. Sure sounds like they built some trucks with the OD off feature and the T/H shifter

 

[DPKetchum]

03/04 does not have tow haul only o/d off.

 

[trqmnstr]

My 04 has Tow/Haul on the shifter. I'm pretty sure it has Tow/Haul as my truck pulls the gears out an extra 400-500 rpms when I engage it. However, overdrive doesn't engage so I'm stumped. What's the deal?

 

[NHays]

Same problem

I have a 04' with a build date of 10/03. I have tow/haul on the gear shift but the truck won't go into OD. The gears hold longer and the trans shifts harder. I have the 305/555 engine. It is a 3500 dually quad 2wd. I need to change my signature.

 

[trqmnstr]

It would be so nice for towing if the damn O/D would engage. Maybe a flash from the dealer?

 

[JimB1]

Seems I've read here that your TCM (transmission control module) doesn't have enough electronics (microprocessor and memory) to do that.