5th Gear Lockout

[CLB]

Hello,

I'm a bit of a Newbie so not sure this post is in the right section. I have a 2005 F250 4x4 6.0L Auto and love the truck so far. My only complaint is when towing in hilly terrain it constantly hops between 5th and 4th gear in Tow/Haul mode (trailer is about 9000lbs with a large frontal area). In this terrain I would prefer to just have it stay in 4th.

Is there any way to lockout 5th gear so the transmission stays in 4th (1:1) or even 3rd overdrive (1.10:1)?? The gear selector only gives you the option of 3rd or OD.

I would love to somehow have this lockout hooked to one of the upfitter switces.

Any help is appreciated!

Thanks.

[risco]

if your run a sct im sure you could have a tow tune written to not going into 6 gear until say 75 or higher btw the shift pattern is 1-2-3-5-6 doesnt use 4 unless below 0 f

[CLB]

Thanks, maybe it's time I contact SCT. I was hoping for something a little more manually operated like a switch on the dash but maybe it's not possible.

I always thought the shift pattern was 1-2-3-4-5 with 3rd+OD (1.10:1) being the "hidden ratio" used instead of 4th (1:1) in cold ambient temps.

Cheers.

[colo_dually]

The only way you are going to be able to hold effective 4th gear, is to have a tow file written not to see a 5th.

Here's my question though, what RPM's and Boost levels are you seeing, and how much are you pulling that make you want to eliminate 5th gear?

[PGreenSVT]

So that everyone can follow this please use the correct gearing which is 12356 without a 4th gear. If you hold in 5th gear you can easily still run at speeds of 70mph. Your fuel mileage will take a hit but that's to be expected. Have an SCT tow tune written that holds off 6th gear shift to 80mph and you're good to go.

[CLB]

Colo_Dually: if I recall correctly I'm seeing around 10psi boost at about 1800-1900 RPM pulling a travel trailer that is approx 9000lbs. It chugs along the flats just fine in OD but once into the rolling hills (especially with a headwind) it keeps downshifting. When in the rolling stuff I'd like it to just stay out of overdrive.

PGreenSVT: Point taken, I will stick with 1-2-3-5-6 and call it "5th" gear that I would like to hold and "6th" that I would like to lock out.

Cheers!

[webefine]

I haul a big truck camper and pull a boat (about 9 to 10,000 lbs) and my truck used to shift in and out of OD all the time. I am now running IDP's tow tune through my SCT and it is night and day difference. I just returned from a trip from WV. to Scranton, Pa. and there where only a hand full of hills that required the truck to shift out of OD. I am stock other than EGR delete and the Tuner.

[CLB]

wewbfine: Thanks for the reply, excuse my ignorance but what is IDP? That tow tune sounds great, but I am not studded and worry about possible side effects on my headgaskets. I do have an EGR delete installed.

Cheers.

[colo_dually]

IDP = Innovative Diesel Performance.

I also run their Tow file, and I have zero issues with the transmission hunting for the right gear.

[CLB]

Is that something that would be safe to run without studs?