Towing in Overdrive??

[Lokin4deer]

Hey all I have the truck in my sig and I was wondering what the opinion on towing in OD is? I have a bigger camper now but in the past I have always just towed in OD and if I came to a big hill I would push the button and turn the OD off. Just wondering what everyone else did? Thanks!!

[transamz9]

I have an '05. I tow in TH even as light as my boat because of the 3rd gear TC lockup. Sometimes I wish I had the OD off option when towing the back roads just to keep it from shifting into OD at 45-50mph. OP, if I was in your shoes (no TH) I would run it in OD until I started getting a lot of unlocking and locking of the TC. I would then lock out OD so it would run in 3rd and locked TC. Go back to OD when back up to maintainable speeds.

The death of the 48 trans is heat build up and when the TC is unlocked it will build heat quickly.I have pulled heavy with my '05 since new and have had it tuned for about half of those years and my original unbuilt trans is still doing great. I run my tuner turned all the way up.

[45Ricochet]

donn0128 wrote:

ib516 wrote:

donn0128 wrote:
The 48re really has no over drive. It is a 4 speed auto with 4th gear being 1 to 1. Tow haul basically only alters the shift points to better utilize the motors torque curve.

Sorry Don, but that's not correct. 4th on the 48RE is 0.69:1 and is therefore, an overdrive ratio.

I stand corrected. Third is 1:1

LOL Don
That there is the difference, you stand corrected when wrong which is a great human feature. To bad OB's can't realize that good trait.
Oh to stay on topic I just run in T/H when towing OP and click again for direct drive on grades which is 1:1. On the flats I use overdrive without any problems.

[Hannibal]

Lokin4deer wrote:
Hey all I have the truck in my sig and I was wondering what the opinion on towing in OD is? I have a bigger camper now but in the past I have always just towed in OD and if I came to a big hill I would push the button and turn the OD off. Just wondering what everyone else did? Thanks!!

I would continue doing what you've been doing. Especially if you use cruise control while towing. That's what I did with my '03 SO Cummins Ram with 47RE and 10.5" AAM 4.10 towing our 10,400 lb high profile 5th wheel.

[donn0128]

ib516 wrote:

donn0128 wrote:
The 48re really has no over drive. It is a 4 speed auto with 4th gear being 1 to 1. Tow haul basically only alters the shift points to better utilize the motors torque curve.

Sorry Don, but that's not correct. 4th on the 48RE is 0.69:1 and is therefore, an overdrive ratio.

I stand corrected. Third is 1:1

[ChooChooMan74]

I know different diesel and transmission, but I tow with my 545RFE in overdrive on the flats (1900 RPMs) and out in the hills (2700 RPMs). I also have it custom tuned to not shift into the 2nd OD (5th) until over 65.

[john_bet]

ib516 wrote:

Lokin4deer wrote:
Just to clarify I do not have a tow/haul button I have a OD on/off button on the end of the gear shifter. Is that one in the same maybe??

No.

My 2007 48RE had tow/haul mode and an overdrive off button (well, the same button actually, press once for tow/haul, twice for OD off, a third time to go back to normal).

Read this --> ALL ABOUT THE 48RE

Does not work that way on my '04.5 and the op has an '03. Push button no od, push again and you have od again.

[boogie_4wheel]

On the 48RE
2003-2004.5: The shifter stalk button locks the transmission out of overdrive. When pressed, the trans will lock the torque convertor in 3rd (1:1).

2005: The button is a tow/haul button. It does not lock the trans out of overdrive. It does allow torque convertor lock up in 3rd, and lower speed lock up in 4th. Does transmission downshifting while slowing down. Manually selecting 2nd gear will lock the torque convertor above 25mph.

2006+: Press button once to engage T/H (acts same as 2005 model). Press button a second time to lock out OD.

Well, since I've got the 05 (and I have not and will not get the computer flash to make my button a lock out only button), I tow in overdrive nearly all the time. My truck climbs all hills at 65 with my sig trailer (~7k with street bike). On heavier trailers I will 'double-tap' to force a downshift to 3rd and let it pull the big hills in 3rd at around 60.

So OP, you can safely run in overdrive. The only issue you may have is low boost/higher EGTs with the slower spinning engine.

[intheburbs]

I was always under the impression that you're putting the least amount of stress on the transmission using whatever gear is a 1:1 ratio. This way, the transmission is simply passing the power through, with no torque multiplication.

I logged ~20,000 miles on my 1/2-ton '01 Suburban pulling a 5500-6000 lb trailer in third. Truck now has 190,000 miles on it, with the original transmission. I've broken other powertrain bits over the years, but the tranny still shifts perfectly.

My current TV has no 1:1 ratio, so I just pick the best gear to minimize gear hunting, be it 4th, 5th or 6th.

[ib516]

Lokin4deer wrote:
Just to clarify I do not have a tow/haul button I have a OD on/off button on the end of the gear shifter. Is that one in the same maybe??

No.

My 2007 48RE had tow/haul mode and an overdrive off button (well, the same button actually, press once for tow/haul, twice for OD off, a third time to go back to normal).

Read this --> ALL ABOUT THE 48RE

[ib516]

donn0128 wrote:
The 48re really has no over drive. It is a 4 speed auto with 4th gear being 1 to 1. Tow haul basically only alters the shift points to better utilize the motors torque curve.

Sorry Don, but that's not correct. 4th on the 48RE is 0.69:1 and is therefore, an overdrive ratio.

[Turtle_n_Peeps]

Just like at the race track, Cummins12V98 holeshot me by a fraction of a second and took the win!!! :B

[Turtle_n_Peeps]

donn0128 wrote:
The 48re really has no over drive. It is a 4 speed auto with 4th gear being 1 to 1. Tow haul basically only alters the shift points to better utilize the motors torque curve.

Hu??? Say what??????

[Cummins12V98]

donn0128 wrote:
The 48re really has no over drive. It is a 4 speed auto with 4th gear being 1 to 1. Tow haul basically only alters the shift points to better utilize the motors torque curve.

4th gear is OD. The transmission has been around since the 60's as the 727 torque flight.

Same with the C-6 Ford and TH-400 GM

Tow in TH and yes use OD just don't let the engine lug. Manually down shift when you know it will need to.

[2oldman]

Lokin4deer wrote:
Thanks oldman I did do a search but didnt find these!

Welcome. They're pretty old, but still relevant.