On my Avalanche the only thing tow/haul does it extend the shift times - I does not keep it out of overdrive. I also tow in 3rd rather than drive - my transmission place showed me the clutches in the transmission and after seeing how small the overdrive clutch is, I never tow in overdrive. Chevy says you can tow in o/d, but their warranty is only 36000 miles - if you keep the truck for the long haul, you will wear out the transmission
With my F250, I'm towing less than half of the rated capacity, so the engine or transmission isn't likely to come under too much strain. It has a transmission temp gauge which hasn't raised above the normal temp under any condition (so far). I still have my previous TV, a 97 Chevy 1/2 ton 4WD, which I used extensively to tow my 1968 Trade Wind, and then the 2005 Bambi, which weigh roughly the same. On flat road it normally tached out at about 1700 RPM, so I rarely dropped it down to 3rd. It's still going very strong with over 100,000 miles.
On my Avalanche the only thing tow/haul does it extend the shift times - I does not keep it out of overdrive. I also tow in 3rd rather than drive - my transmission place showed me the clutches in the transmission and after seeing how small the overdrive clutch is, I never tow in overdrive. Chevy says you can tow in o/d, but their warranty is only 36000 miles - if you keep the truck for the long haul, you will wear out the transmission
Ken J.
I see the exact same as you do Ken. As for O/D, one of the other things I think T/H does, at least on GM, is lock the torque converter sooner than later and an unlocked torque converter is what generates a lot of the heat. I towed several thousand miles with my Impala SS in OD and I reprogrammed the PCM to lock the TC sooner than later. If the engine did a lot of hunting (because it didn't have tow haul), I'd go to 3rd for those short times, then back into O/D. The car now has 95k on the clock and it's still goin' strong. I would imagine the factory T/H with the factory saying it's ok should be good to go. My trans temps rarely get near 200 and although the engine will downshift on some bridges, even on flatland, it still is all good. The burb now has over 11k, mostly towing and it seems happy as the Impala does. Of course, I change fluids all down the driveline regularly which may or may not have helped my SS live so long.
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I haven't heard anyone concur about the braking assist in TH Mode?
Yea, the Allision is a great trans.
I too agree, that at least the 4L80e in T/H mode doesn't provide any additional braking that I can tell.
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Computers manufactured by companies such as IBM, Compaq and millions of others are by far the most popular with about 70 million machines in use worldwide. Macintosh fans note that cockroaches are far more numerous than humans and that numbers alone do not denote a higher life form. -NY Times 1991
One quick example, 2 mile 8% grade, I was going faster than I wanted to, I tapped the brakes, got to 50mph and the truck went the whole 2 miles selecting the correct gear.
I didn't touch the brakes, other than the first time.
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Bob
'77 Sovereign Intl 31' CB '07 GMC 4x4 2500HD EC 8.1 Allision six | Bedrug | Softopper | Airbags
WBCCI Time's a-changing Say no to Lawrence Welk attitudes
They just keep improving the Allison - but even with my '03 I haven't got any complaints. It just requires a tad more imput from the driver (---touching the brake to make it shift when going downhill.) As for "Tow/Haul" mode, I use it anytime I'm towing the Airstream. Once you get over about 57 mph T/H is no longer a factor. When travelling in the flatlands, it still makes life easier on the engine and tranny by delaying the shift points - so I still find it to be beneficial. I get around 14 mpg towing and 18 to 21 solo - and I use cruise control religiously, except in the mountains.
Four years and 56,000 miles of nothing but pure enjoyment from the 2003 GMC Duramax/Allison!
I have whatever transmission Ford put in the F-250 Powerstroke in '05...I know, I'm so knowledgeable about mechanical things. I put over 180K miles on my F-150 (never towed with it) and kept if for 12 years. I figure I'll keep this truck even longer so I don't want to wear it out prematurely. So whenever the Airstream is behind me, the tow/haul button is pressed. I just wished the idiot light to remind me it was on was a different color. That yellow light that reads "tow/haul" is distracting and makes me think something is wrong. Why couldn't it be green like the cruise control light? Anyway, I would rather buy a few extra gallons of diesel every trip than a new transmission @ $3-$4K during the life time of this truck.
I will check my manual though because a good bit of my longer trips cover the flat lands between central Georgia and central Florida. My Airstream weighs 6,500 #'s dry and loaded I figure around 7,500 #'s and that is a little over half my truck's towing capacity. I do use the cruise on the interstate and every other chance I get.
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2008 F-250 Lariat Power Stroke Diesel Crew Cab SWB
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i take it in and out of th to get it to shift into od when towing in a 55 mph
zones.the allison has no problem pulling in od. trans temps are always under
200.
Whenever the Trailer is attached. no matter how short or mlong the trip even if it is around the hangar. They put it ther for a reason. My Classic is the only thing I have ever towed with it.
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Michelle
I'm not afraid I learned to drive in Washington, DC
Sarah
Ruby, (05 BMW R1200RT) serviced and put to bed for the winter
Daisy, (06 Diesel F-250 w/Tow Command)
Butter Cup, (06 Classic 31 w/dinette, solar) http://Michelles-Adventures.US
I use the T/H as often as I remember to press the button, which is most of the time once I get into the road routine. I would appreciate an idiot sensor on the hitch that turned it on automatically when a load was on.
Curious if anyone has ever overheated their trannie by not using TH.
I've had success with cruise on flat or rolling country (big, long prairie hills) by setting the cruise just a tad lower than desired speed. As I approach a hill I manually accelerate over the cruise set speed (to desired speed or a bit above) to avoid the drastic downshifts that cruise brings on. I'm not running a heavy load so I don't think cruise is hurting anything but wouldn't be the first time I was wrong.
What are the reasons for not using cruise?
Mileage is usually 10-14. Best mileage I got was late afternoon last summer in eastern Montana - 17 mpg. The air was cool and calm and I didn't want to stop. Rode right into the sunset.
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