[bugman]

when i push the tow/haul button i notice on my truck it doesn't even feel like it down shifts. the rpm's don't even go up. on the 06 i had i know when i pushed the tow/haul switch it would lug down and the rpm's would increase. is this because the 07 6.7 has the 6-speed tranny or what? when i push the tow/haul switch with the exhaust brake switch depressed and go to slow down it down shifts automatically, kinda hard. is this normal? just trying to figure out all the new stuff..lol. i guess i could read the dummy manual huh? thanks alot for any info on this.

 

[bugman]

anyone?????????????

 

[Buck08]

Yep they downshift pretty hard with the EB on not pulling anything heavy. At least our 08 does!!

 

[bugman]

thanks buck 08. preciate the info

 

[niedhogg]

It's normal, I wouldn't worry about it. The 6-speeds autos are much better. When I used tow/haul on my 04 it would never go into overdrive. The hard downshifts are because the tranny along with the exhaust brake designed to help slow you down if your towing a heavy load. I like to use it when I'm hauling my bike, I barely have to use the brake.

 

[bart9505]

downshifting is normal if you have the latest flash, and something I have stopped using when empty and the exhaust brake is on, cause the people behind me don't see brake lights and have come pretty close to hitting me a few times. I also found the tow/haul downshift a little annoying when towing 12,000 lbs of tractor and trailer and the exhaust brake off, when on flat ground in stop light land. Every time you roll to a gentle stop, the transmission shifts down through the gears, which thumps the hitch pretty hard if you aren't using the brake enough to keep the hitch parts compressed.
Also, when towing a heavy trailer but no load on the truck other than the 500 or 600 lbs of tongue weight, be careful with the tow/haul/eb combo on wet pavement. It can break the back tires loose on a decent grade. I also had more power than traction climbing the same hill, and the limited slip is not forgiving.

 

[rxr]

The tow/haul button changes the shift patern on the 6-speed auto but it does not lock out any gears. It also often takes longer to shift into the upper gears to help keep power up for heavier weights. On the old 4-speed, from what I understand, it locked out the overdrive. The tow/haul (w/6speed auto) helps lock the torque converter and, rather than droping to idle as the vehicle slows down, it actually pulls into the next gear to and helps keep the transmission engaged so the engine brake can work as you slow down. The e-brake will work when you are not in tow/haul but it often will not last more than one gear then it drops to idle.