Towing Mode for Chev/GMC pickup

[Slow but Steady]

I am somewhat confused, and looking for help. When I tow my 6200 pound camper on normal level highways (no mountains, steep grades), should I keep my transmission in the towing mode (pushing the button at the end of the shifter)?

My service writer at the dealership tells me to keep in towing mode at all times when pulling ( I normally tow at 55 mph)

A friend of mine says he only uses the towing mode when going up or down hills/mountains.

As you can tell we are new at this.

Thanks for any and all help

Tom and Kathy

[bigmurph]

Could you give us more info on your truck? What year and engine? 1500 or 2500? I was a tech at a chevy dealer and I still build transmissions for chevys. The tow/haul should be used whenever the load is 50% or 75% of the weight truck. More than likley you will need to use it. I use mine everywhere I go and I only tow in 3rd gear. 07 1500 Crew Cab 4x4 5.3 3.73 gears.

[Mr. Dan]

Duplicate threads merged by site team.

[Slow but Steady]

I once again on to thank for each and all reply to my question. The info that is provided here each day is "priceless" to newbies like my wife and I. I hope at some point in time we can help other beginners.

Tom and Kathy (N. Ga)

[DreiHunde]

Originally Posted by timfromma

If I have ANYTHING hooked to my hitch, the Tow/Haul mode is on.

Pretty much an Easy Peasy decision.

[yetavon]

Originally Posted by BandJCarm

Confused........

If the truck never shifts, then what is the 'hurt' with having the Tow Haul mode "ON"? IF it's "on" and it never shifts, then that's the same as having it off. But if it's "on" and it just might, maybe, on occasion that you haven't thought of, DOES shift, wouldn't that be better while towing?

??

On or off, flat road no shifting....no difference at all.
WHEN it downshifts.....T/H Off.....it will shift at a lower RPM, at a softer line pressures for more comfortable ride feeling, since your TC unlocked your building heat, now lugging somewhat due to lower RPM(minimal) you build your momentum back up, again up shifting at a lower RPM, softly shifting for comfort, building more heat from slipping clutches....
T/H ON ....you get quicker firmer shifts, sooner to prevent loss of momentum, higher line pressure minimizes slippage in your clutch packs, and your upshift is higher in the RPMs...this all helps keep the fluids cooler.
So an occasional shift or 2 is not a problem with a fair load, but if its constantly jumping around, T/H needs to be on....the heat will kill the transmission in time.

[yetavon]

Originally Posted by gfarmcafe

If you're talking to me, we have a 2002 Silverado and yes, it does have "harder feeling shifts" when the T/H mode is used. I've always wondered if this may be damaging the transmission, U-joints and/or rear end. Can I sleep better now?

Yup you can....The softer shifts in any automatic are achieved by slowly applying pressure to the clutch packs, thus creating more heat...and heat is a transmissions worst enemy

[rockfordroo]

Originally Posted by f5moab

Page 342 of a 2016 GMC/Chevy owner manual:
Tow/Haul is designed to be most effective when the vehicle and trailer combined weight is at least 75% of the vehicle's Gross Combined Weight Rating (GCWR).

See “Weight of the Trailer” under Trailer Towing.
Tow/Haul is most useful under the following driving conditions:

. When pulling a heavy trailer or a large or heavy load through rolling terrain.

. When pulling a heavy trailer or a large or heavy load in stop-and-go traffic.

. When pulling a heavy trailer or a large or heavy load in busy parking lots where improved low speed control of the vehicle is desired.

Operating the vehicle in Tow/Haul when lightly loaded or with no trailer
at all will not cause damage. However, there is no benefit to the selection of Tow/Haul when the vehicle is unloaded. Such a selection when unloaded may result in unpleasant engine and transmission driving characteristics and reduced fuel economy. Tow/Haul is recommended only when pulling a heavy trailer or a large or heavy load.

Page 341
If charging a remote (non-vehicle) battery, press the Tow/Haul Mode button, if equipped, at the end of the shift lever. This will boost the vehicle system voltage and properly charge the battery. If the trailer is too light for Tow/Haul Mode, or the vehicle is not equipped with Tow/Haul, turn on the headlamps as a second way to boost the vehicle system and charge the battery.

My 2016 2500HD gasser's owner's manual says the same thing.

It also says:

Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is only enabled while the Tow/Haul
Mode is selected and the vehicle is not in the Range Selection Mode.
See “Tow/Haul Mode” listed previously and Manual Mode on pg 292.
Tow/Haul Mode Grade Braking assists in maintaining desired
vehicle speeds when driving on downhill grades by using the engine
and transmission to slow the vehicle.

On vehicles with a gasoline engine,to disable or enable Tow/Haul
Grade Braking within the current ignition key cycle, press and hold
the Tow/Haul button for five seconds. When the button is
released, the requested mode change is made. A DIC message is
displayed. See Transmission Messages on pg 162.

On vehicles with a diesel engine, Tow/Haul Mode Grade Braking can
be enabled or disabled by pressing the Tow/Haul Mode button. Use the
exhaust brake and Tow/Haul Mode for maximum grade braking.

My GCWR is 21,100 lbs, so 75% is 15,825 lbs. My TV GVWR is 9,500 lbs and my TT's GVWR is 6,538 lbs, for a GCW of 16,038 lbs. So I'm right at 75% using the max weights. Since neither the TV or the TT is fully loaded, I'd say I'm under the 75% value, probably around 70%.

I don't normally use the T/H mode, as I don't really think I have any problems getting off the line, so to speak. Also, I'm in the relatively flat midwest. But I can see using it for the grade braking if/when I get into some good sized grades.

[B and B]

I run Tow/Haul mode when dry, with exhaust brake, on ice and deep snow in 4 x 4. Does great, keeps truck straight on ice.

[jtesta1]

If you think you are smarter than a computer than by all means drive as you want. I personally think that the people who designed the computer are a bit smarter than I. So i drive with the tow mode engaged and also the cruise control. Have been for years now and have not had any problems or issues while traveling.

[Waynedeer]

I think you will find you get a little better mpg in Tow/Haul. I did in my 2008 Chevy 2500 HD Diesel

[dmchapman]

Originally Posted by rockfordroo

My 2016 2500HD gasser's owner's manual says the same thing.

It also says:

Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is only enabled while the Tow/Haul
Mode is selected and the vehicle is not in the Range Selection Mode.
See “Tow/Haul Mode” listed previously and Manual Mode on pg 292.
Tow/Haul Mode Grade Braking assists in maintaining desired
vehicle speeds when driving on downhill grades by using the engine
and transmission to slow the vehicle.

On vehicles with a gasoline engine,to disable or enable Tow/Haul
Grade Braking within the current ignition key cycle, press and hold
the Tow/Haul button for five seconds. When the button is
released, the requested mode change is made. A DIC message is
displayed. See Transmission Messages on pg 162.

On vehicles with a diesel engine, Tow/Haul Mode Grade Braking can
be enabled or disabled by pressing the Tow/Haul Mode button. Use the
exhaust brake and Tow/Haul Mode for maximum grade braking.

My GCWR is 21,100 lbs, so 75% is 15,825 lbs. My TV GVWR is 9,500 lbs and my TT's GVWR is 6,538 lbs, for a GCW of 16,038 lbs. So I'm right at 75% using the max weights. Since neither the TV or the TT is fully loaded, I'd say I'm under the 75% value, probably around 70%.

I don't normally use the T/H mode, as I don't really think I have any problems getting off the line, so to speak. Also, I'm in the relatively flat midwest. But I can see using it for the grade braking if/when I get into some good sized grades.

Thanks for the info on grade braking. I somehow missed reading that in my owners manual. My Ford F450 work truck went into that mode automatically and I have found myself wishing for that feature for the year I've been hauling with my new to me 2012 Silverado. 👍

[Burk]

2006, Chev 6.6 duramax, does anyone else have the problem of downshift control when applying brakes (moderately) Mine will downshift way to early causing hi-rev that is not necessary. I wish I could talk to the software Guru that wrote the code
Burk

[keeprr]

If I remember correctly the tow haul mode, cruise control and engine brake work in unison. I always use tow haul, engine brake and cruise control when not in congested areas. I especially use cruise control, towing haul and engine brake in mountains. Set cruise at 65 and truck goes up at 64/65 and down at 65/66 and I haven't needed to used the brakes.

[Big Bill]

I have a 05 gm diesel On a long grade when using drive I always use tow/haul so that alowed the trans to lock in drive , always keep an eye on the trans temperature

[DouglasReid]

Originally Posted by Slow but Steady

I have an RV trailer that weights about 6200 dry, and about 7000 lbs loaded. When I am driving on normal roads (not up and down grades/hills/mountains) is it best to still keep the automatic trans in the "towing mode" (by pushing the button in at end of the shifter)? I have hear mixed opinions, and of course I don't tow over 55 mph.
Thanks so much.

You did not mention anything about your truck. IF you have a Duramax Diesel engine with the Allison transmission you must have it in tow/haul mode in order to have the benefit of transmission braking when slowing down.

[labcamper]

X3

[mike.t]

In tow/haul mode the engine brake works so well it will impress the hell out you the 1st time you go down a mountain

[robbdrell]

Just got a new a new GMC and haven't towed my 30' TT yet. So with my DuraMax when do I use the exhaust brake? With the tow/haul mode? Please don't tell me to read the manual and push the button. LOL

[dannyabear]

Originally Posted by robbdrell

Just got a new a new GMC and haven't towed my 30' TT yet. So with my DuraMax when do I use the exhaust brake? With the tow/haul mode? Please don't tell me to read the manual and push the button. LOL

OK, mail me the book, I'll read it then tell you when and how to use it.