Tow haul mode

Time for Skid Row to get tuned in with the new transmissions. They are designed for grade braking. Coming through western New Mexico from Show Low and through Montana and Wyoming I used my T/H to minimize braking and watched by transmission temps. carefully. It never raised temps. more than 10-15 degrees above flat land towing did.

Skid Row Joe wrote:
With a trans overhaul or replacement that runs $3,000+ and a brake job running a few hundred - the math is easy on which system to brake with.

Anywhere, in the United States auto transmission downshifting will potentially harm the transmission. My Ford PSD's owners manual specifically states not using it as a braking device. If your method works for you have at it, but it does your trans. no good - whether you realize it or not is the only difference here. That includes Colorado, btw.:W

S'funny, my Owner's Manual says:....
"Driving On Grades
Reduce speed and shift to a lower gear before you start down a long or steep downgrade. If you don’t shift down, you might have to use your brakes so much that they would get hot and no longer work well.
If you have an automatic transmission, you can tow in DRIVE (D). You may want to shift the transmission to a lower gear selection if the transmission shifts too often (e.g., under heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the transmission shifts too often."

Think I'll keep using my Tow/Haul and engine brake so I don't cook the service brakes to the point of fade thank you!

Can't be - my auto transmission is 1,000 times better than any transmission you and your pappy used. That includes your Allison transmission. I'm not hurting one bit.

Just say'n, :B

shepcal wrote:
S.R.Joe- my Allison is 100 times better than any tranny your pappy used. I'm not hurting it one bit.
I went from 2.45's to 2.65's on my 07 Chevy Duramax and have found I get better mileage even when not towing in T/H

Just say'n, Shep

Again, people seem to think they're smarter than the truck company engineers and why doesn't anyone read the owners manual anymore?

Use Tow/Haul when you are Tow/Hauling something. It's really that simple. You want better mileage? Sell your trailer.

T/H mode keeps your trans in a lower gear longer, yes... But that's because it's not UNLOCKING the torque converter which will generate a TON of heat in the fluid in a matter of MINUTES... ;)

So, if you like the fact that you are running in a higher gear, but in an UNLOCKED TC condition, you obviously don't pay attention to your trans temps... ;)

I'd rather run higher rpms in a LOCKED TC condition than a lower rpm UNLOCKED and generating a TON of heat in my trans.... :)

That's just me, so do as you feel works best for you.. ;)

Mitch

It can case more damage to engine if using to high a gear than to use more revs and lover gear if gearbox starts hunting definitely lock in lover gear.
Frank.

S.R.Joe- my Allison is 100 times better than any tranny your pappy used. I'm not hurting it one bit.
I went from 2.45's to 2.65's on my 07 Chevy Duramax and have found I get better mileage even when not towing in T/H

Just say'n, Shep

Anytime my trailer is hooked up the transmission is in the tow/haul mode. The Pentastar V6 really pulls my TT well. I limit the upper gear to 6. It rarely shifts at highway speed unless I'm going up a long hill.

EcoBullet wrote:

Skid Row Joe wrote:
do not use that button to downshift the rig to brake it's speed. Use the foot brake, by a push and release methods so as not to burn up the brakes with a constant push on them. The transmission will wear adversely if you try using it as a braking device, especially on those long, steep grades.

I'm no expert, but this is just about backwards of what I've always read, and done myself. I think I've even read in an owner's manual or two that you should downshift when descending hills to allow the engine to brake, rather than overusing your brakes. If you go down much of a hill and don't use any sort of engine braking, you stand a good chance of brake failure due to overheating, even if you do push and release. Your method might work in Texas, but please don't try that in the mountains of Colorado.

With a trans overhaul or replacement that runs $3,000+ and a brake job running a few hundred - the math is easy on which system to brake with.

Anywhere, in the United States auto transmission downshifting will potentially harm the transmission. My Ford PSD's owners manual specifically states not using it as a braking device. If your method works for you have at it, but it does your trans. no good - whether you realize it or not is the only difference here. That includes Colorado, btw.:W

johndeerefarmer wrote:
Tow/haul holds each gear longer so you should use more fuel. In other words instead of shifting into 6th at 1800rpm it might do it at 2000rpm. Th higher the rpm, the more fuel is used. I leave it off unless the truck is frequently hunting gears or if I need it for engine braking.

Not necessarily true - if the engine is not laboring and is producing the same power, the fuel usage will be the same.
In addition, the torque converter clutch locks up in the lower gears to save transmission oil temps. If there is less heat going into the trans fluid, then there may be a tad less fuel being used.
I have not noticed any fuel economy difference using T/H but I sure like the engine braking.