i should have got a manual but i didn't so thats that. to compensate for this questionable decision i love using tow haul mode even with no load although i am always going up or down hills/smaller mountains. does using this setting cause increased wear on the trans or have any disadvantages or better yet any advantages?

 

tow/haul mode lengthens the shift points and doesn't downshift as much as if you were hauling something with tow/haul on. using the tow/haul basically saves the tranny from shifting so much going up hills and hold the gear longer going down hills when hauling. not sure on long term affects driving empty.

 

I would think that it would exstend tranny life because of less down shifting a slipping. all the excess downshifting and slipping is what builds up heat.

-Troy

 

Out of curiosity, since the 06 tow/haul mode has OD why would there be less downshifting when going up hills? If it doesn't have the power to maintain OD out of tow/haul I don't think it will have any better luck using tow/haul ... it will still downshift. T/H locks the tc in 3rd/4th, but I doubt there is that much difference between locked and unlock OD capability.

Just curious, I haven't had a chance to tow with my dually yet. I get the hitch put in tomorrow.

I had the Jake Brake added and that also locks the tc in 3rd and 4th but doesn't seem to change the shift points like T/H. It will downshift the tranny for braking though.

 

In addition to less frequent shifting, the torque converter clutch locks up earlier, and stays locked. When locked, you should get better mileage (less wasted energy)...in addition to lower tranny temps (less friction).

Id say the main disadvantage to using it is that your ride will not be as smooth. You'll probably notice that the ride is a little more jerky as a result of the TC locking up more often.

 

does the tranny shift faster as well with t/h? I know with older trannys that have a shift kit I was told that it extends the life shifting a bit harder since there is less slippage just my thoughts

 

Tow/Haul works well going down a grade unloaded. You dont have to ride the brakes because it will downshift for you instead of coasting when you let off the accelerator.