Towing With 2011 1500 5.3 And 6speed Questions

03SilverSilverado · August 21, 2011

I have the same setup, 5.3 3.42's and the 6 speed. I have an 18 foot Fish and ski that comes in with the trailer around 3000-4000 depending on loadout. I activate the tow/haul mode when getting up to highway speeds, and then if I will be cruising on flat highway for a while, I'll disengage it to get the rpms down.

That being said I would recommend setting the tow/haul mode and letting the truck do what it feels necessarily. It's been my experience that it will downshift pretty intuitively depending on the grade you're on and the amount of throttle you're giving it. It will hold the gear nicely to keep you in the powerband as well. I was very pleasantly surprised at how nice the tow/haul mode works on the 6 speed. You can still get into 6th even in tow haul mode but I think it keeps the TC unlocked, not positive though.

Now if I could get an "assertive driving mode" setting in there so that when tow/haul is off it didnt shift quite so early, then I'd be the happiest man on the planet!

sgtjetdrive · August 30, 2011

Ok, I have a 6 spd 3.42 combo in my truck. I love the combo because it allows the driver to shift when he wants to and not the computer and yes compared to my last one(3.73 with a 4spd auto/same trailers) it tows better. So in hilly terrain, while towing, I put in manual mode and hold to a gear of my choice depend on conditions. I always use tow haul in manual mode. Now on the highway I use the drive position and in tow haul and let it do it's thing. I have found if you exercise slow throttle movments it will shift down one gear at a time on grades. Get a heavy foot and it will drop two gears and rev things up a bit prematurely. If you watch the tach you can see when the TC unlocks and in trailer mode it tends to stay locked a little longer than normal. Watch trans temp on the long hills and you may see more temp than you like and a downshift may be in order even though the engine is still pulling the load. Just because you can pull a hill at a higher speed doesn't mean you should. Heavy throttle means TC unlocked and more heat being made. I prefer to select a gear to pull steep grades the allows part throttle to get the job done. Allow the engine torque to do the work and not rev into high horsepower range. If my foot is on the floor for more the a minute max then I drop a gear. I like my truck want to keep it alive. With all of this said know that I tow in the mountains often and grades of 7-12% are normal. I have been towing with this mindset for years and have never broke anything on any of my tow vehicles.

HawkScot · August 30, 2011

Keep it in D and use Tow/Haul mode. Sometimes on flat ground, I take it out of T/H to let it upshift and then put it back. If you find the terrain causing the truck to shift up and down more than you like, you can use M to limit the upshifts.

Space74 · September 6, 2011

I have the same setup in my 2011 Sierra and I pull a 6700lb TT. I use t/h and run it in M5 on the highways. The RPM stays about 2200 give or take. It hauls like a trooper.

flatlander · November 7, 2011

Guess it all has been said by others but I too have had the 5.3 with the 4speed & 3.73 gears, and thought it was the optimum rig. Now I have a 5.3 with the 6 speed & 3.42 gears and mostly love the combination but wish GM had the 3.55 gearing like the F150 Fords. When towing my small 18' tandem axle travel trailer I just put it in D with the TowHaul On and go but find it shifting down into 3rd gear more often than I would like. Shifting between 4th and 5th I can expect but 3rd gear really put the revs up. Find that about 60-62 mph is the optimum speed for getting the best gas mileage and even then I am only getting mileage in the 8.5 to 9.5 range. The little trailer only weighs about 3800 lbs so am guessing that wind resistance is the biggest factor.

music · November 7, 2011

Guess it all has been said by others but I too have had the 5.3 with the 4speed & 3.73 gears, and thought it was the optimum rig. Now I have a 5.3 with the 6 speed & 3.42 gears and mostly love the combination but wish GM had the 3.55 gearing like the F150 Fords. When towing my small 18' tandem axle travel trailer I just put it in D with the TowHaul On and go but find it shifting down into 3rd gear more often than I would like. Shifting between 4th and 5th I can expect but 3rd gear really put the revs up. Find that about 60-62 mph is the optimum speed for getting the best gas mileage and even then I am only getting mileage in the 8.5 to 9.5 range. The little trailer only weighs about 3800 lbs so am guessing that wind resistance is the biggest factor.

I'm curious, did your 4-spd/3.73 downshift to 2nd at the same places the 6-spd downshifts to 3rd? I'd guess that it would, but also know that the 4-spd unlocks 3rd and bumps up the rpm a bit, and then downshifts to 2nd *if* the unlocked TC mode isn't enough power. I'm now pulling closer to a 7000 lb camper, but my previous ~5000 lb camper rarely saw 2nd on the hwy @ 60 to 65 mph w/ the 4-spd/3.73 combo. I don't usually see 2nd very often w/ the 7000 lb camper, but had some tiring days with it in 30 to 40 mph head winds (60 mph gusts) this summer in TX & NM.

solotworacer · December 26, 2011

It depends on options that you have on the truck. Let me explain a little better. Do you have the K5L option on your truck? Well according to the owners manual you more than likely have the K5L HD Cooling package as they do not rate the 5.3, 3.42, crew cab with out.

2WD 9600#

4WD 9500#

jbrown2011 · December 30, 2011

I have the 2011 GMC Sierra Crew Cab with 5.3 / 3.42 / 6spd tran. I was wondering how to look the vin up and just double verify that I have the K5L HD Cooling. I,m going to be pulling a trailer around 7500lbs. As stated above the owners manual shows all the crew cabs with the 3.42's to have max trailer weight's of 9600 lbs and a GCWR of 15000 lbs. I really wanted the 2500 but the $$$'s were an issue. I did see a much larger transmission cooler on the 2500, wish I could upgrade.

wavery · December 30, 2011

I have the 2011 GMC Sierra Crew Cab with 5.3 / 3.42 / 6spd tran. I was wondering how to look the vin up and just double verify that I have the K5L HD Cooling. I,m going to be pulling a trailer around 7500lbs. As stated above the owners manual shows all the crew cabs with the 3.42's to have max trailer weight's of 9600 lbs and a GCWR of 15000 lbs. I really wanted the 2500 but the $$$'s were an issue. I did see a much larger transmission cooler on the 2500, wish I could upgrade.

Your biggest challenge will be keeping the payload within limits........

Look at the RPO tag inside your glove box and see if it has KL5 listed. If it doesn't, you don't have it. It lists all of the options that YOUR truck was built with.

What is your payload rating and your rear axle rating?

Your trailer will have a tongue weight of around 800-1000#. That will eat up a lot of payload. Also, check your tire ratings.

I am right at the top of my limits with my 1500 and I pull a 4K# trailer with a 500# tongue weight.

BTW...... adding a larger trans cooler is easy and it is essential..... here's mine, you'll need a bigger one.

The grille pops right out.

terzmo · January 14, 2012

I pull a loaded one car trailer in the haul/trailer mode with a 2010/6 speed/5.3 with 308's and it does fine.

Stevens03 · January 15, 2012

I pull a loaded one car trailer in the haul/trailer mode with a 2010/6 speed/5.3 with 308's and it does fine.

Ta-heck with the towing, I'd love to have the car Very nice.

nickvrebel · January 27, 2012

I have a 2009 5.3L/6 speed/ 3.42s. Over the summer I pulled a 16' tandem axle utility trailer with a John Deer 990 tractor that was equipped with a loader and a disc set. My truck had no issue what-so-ever, I kept it in drive and activated tow haul mode.