Real World Towing With 2009 5.3l 6 Speed 3.42 Gears

blevenson · June 11, 2010

Just completed the first trip with any real weight on the truck.

2009 Crewcab z71 with 5.3L 6sp and 3.42 gears - Stock (well Weathertech mats, underhood jumper cable storage box, bedliner, roll-up tonneau and Line of Fire LED lightbar but no performance mods).

I was hooked up to a boat/trailer combo that I am estimating is around 5,000 lbs (design weight of boat is 2,900lbs, however with all the gear onboard the real world weight is in the neighborhood of about 3,500 - 3,700 lbs. and I am estimating the trailer at 800-1,200 lbs - you guys may have a better idea on the trailer weight - It's 35 ft long).

I towed about 45 miles today, primarily highway with moderate hills averaging 55-60 mph. I never saw the trans temp climb over 165 degrees (outside temp was 67 and humidity was about 90+% as it was just starting to rain) and spent most of its time in the 149-156 degree range. The higher temps came on a 2.5 mile 2% grade at 55-60 mph. On the ride to get the trailer over the same terrian the trans temp was consistently 142 degrees at 70-75 mph. Hand calculated mileage was 10 mpg (DIC agreed). I was using Tow/Haul and limited the truck to 5th gear.

I was quite impressed with the truck (had an 09 CC 4.8L 4sp with 3.42 gears previously). Grade braking was awesome and the trans felt strong and decisive. Off the highway wasn't the smoothest ride, but I am blaming that on the trailer's surge brakes (I know elec brakes with the controller are better but you dont find them much in the boating world).

I know it isnt the 6.2L, but since the majority of my miles (30,000+ miles per year) are highway running basically empty, the 5.3L is plenty for me and I think it's was a great tow vehicle for the 5k lbs range. Wouldnt attempt the 9,500 lbs the truck is rated for, but to each his own.

Since the shape of the boat makes it somewhat prone to sway, my question is whether or not LT rated tires will help reduce it. I was running my stock Goodyear Wrangler A/Ts at 39lbs and the trailer is not and will not be equipped with any WD hitch set up. Should I think about going 40-42lbs when towing this setup? I am going to get LT rated tires when its time, but plan on running these for their lifespan unless it will have a BIG impact on trailer sway.

Thoughts?

[email protected] · June 11, 2010

BEAUTY BOAT!

Sorry, not much help with the LT tire stuff, but it would mainly depend on the tongue weight. Did it sag much in the rear?

blevenson · June 11, 2010

BEAUTY BOAT!

Sorry, not much help with the LT tire stuff, but it would mainly depend on the tongue weight. Did it sag much in the rear?

Didnt notice much sag on the truck. I would say it leveled the truck. Given the trailer design though I cannot increase the tongue weight. I could load the bow with the gear but it wouldnt be too good for the boat - a catch 22 I guess. The majority of the weight is in the lead keel and is centered over the axles

VT_Z71 · June 11, 2010

ahhhhh...you can't beat a good J-Boat

2005LT · June 11, 2010

I was asking myself the same question about LT tires after towing a 24' cargo trailer a few weeks back. Trailer also weighed about 5k lbs but the tongue weight was enough to make the rear of the truck sag pretty good. I also have the factory Goodyear Wranglers. Did not use a WD hitch in the pic below. At 60 mph, the rig did NOT feel stable. Truck was "twisting" pretty good.

I think some good LT rated tires with better sidewalls would have helped. Maybe some air bags too.

smattei14 · June 11, 2010

I was asking myself the same question about LT tires after towing a 24' cargo trailer a few weeks back. Trailer also weighed about 5k lbs but the tongue weight was enough to make the rear of the truck sag pretty good. I also have the factory Goodyear Wranglers. Did not use a WD hitch in the pic below. At 60 mph, the rig did NOT feel stable. Truck was "twisting" pretty good.

I think some good LT rated tires with better sidewalls would have helped. Maybe some air bags too.

Some Air Bags would be good...you are sagging a bit in the rear. You could get away with it but I would add them.

What are you towing in the trailer?

Could you push some of the weight back so you have less tongue weight? Just an idea.

wages999 · June 11, 2010

I've run stock Bridgestone Dueller At's, Goodyear Wrangler ST's, and Goodyear Wrangler AT/S' on my truck. All the tires were stock P-rated tires with basically the same weight rating. Both sets of Goodyears had much softer sidewalls and you could feel the back-end of the truck swaying a little when towing a car on an open car trailer. The Dueller's didn't have the swaying issue. I just got a set of LT Goodyear Wrangler's in load range C. I haven't towed anything heavy yet, but I haven't felt any sway with just an empty car trailer (~2,100 pounds) on behind my truck.

blevenson · June 11, 2010

I was asking myself the same question about LT tires after towing a 24' cargo trailer a few weeks back. Trailer also weighed about 5k lbs but the tongue weight was enough to make the rear of the truck sag pretty good. I also have the factory Goodyear Wranglers. Did not use a WD hitch in the pic below. At 60 mph, the rig did NOT feel stable. Truck was "twisting" pretty good.

I think some good LT rated tires with better sidewalls would have helped. Maybe some air bags too.

Did you upgrade your hitch from the one that comes with the towing package from the factory? The factory hitch is marked for 5,000 lbs with 600 lbs Max Tongue weight or 10,500 lbs and 1,100 lbs tongue max with a WD hitch setup...

What are the real world implications of these numbers? Liability issue if something happens and its determined you exceeded the rating without the WD hitch, or hitch failure?

The sag on your truck makes me think you were over the 600 lbs limit. I know I was in the 400 lbs range and had minimal sag.

2005LT · June 11, 2010

The trailer is basically my dad's wood-working "shop on wheels". It was fairly empty at the time just with a couple storage cabinets at the front and some misc tools scattered throughout. He has since added more cabinetry and wired it up for lighting and power outlets.

Blev, thanks for the tip on the hitch rating. No, I have not upgraded it. Between my dad and I we just bought a 12k lb rated WD hitch so that should put me back inside the weight rating. Didn't realize I was pushing over the limit before.

blevenson · June 11, 2010

2005LT - I'd be interested to know how the ride/sway changes with the new hitch. Hopefully a big improvement. Probably a lot more than the LT rated tires will give you, but I still wonder about that concept too.

If the rule of thumb is to stay within 2/3 the total capacity for the truck when towing, does that apply to the hitch ratings too? Does that make the 5,000 lbs hitch rating only really appropriate for 3,350 lbs?

Seems like the hitch is well undersized for the truck then.

Thoughts from those of you towing 5k+ with the GMT-900...did you upgrade from the factory hitch?

music · June 11, 2010

I tow a ~7k lb camper (loaded) with the stock hitch and a Reese Dual Cam WD hitch system. No issues, handles great. I'm probably right at the WD hitch rating on tongue weight.

Mudddawg · June 11, 2010

Just completed the first trip with any real weight on the truck.
2009 Crewcab z71 with 5.3L 6sp and 3.42 gears - Stock (well Weathertech mats, underhood jumper cable storage box, bedliner, roll-up tonneau and Line of Fire LED lightbar but no performance mods).

I was hooked up to a boat/trailer combo that I am estimating is around 5,000 lbs (design weight of boat is 2,900lbs, however with all the gear onboard the real world weight is in the neighborhood of about 3,500 - 3,700 lbs. and I am estimating the trailer at 800-1,200 lbs - you guys may have a better idea on the trailer weight - It's 35 ft long).

I towed about 45 miles today, primarily highway with moderate hills averaging 55-60 mph. I never saw the trans temp climb over 165 degrees (outside temp was 67 and humidity was about 90+% as it was just starting to rain) and spent most of its time in the 149-156 degree range. The higher temps came on a 2.5 mile 2% grade at 55-60 mph. On the ride to get the trailer over the same terrian the trans temp was consistently 142 degrees at 70-75 mph. Hand calculated mileage was 10 mpg (DIC agreed). I was using Tow/Haul and limited the truck to 5th gear.

I was quite impressed with the truck (had an 09 CC 4.8L 4sp with 3.42 gears previously). Grade braking was awesome and the trans felt strong and decisive. Off the highway wasn't the smoothest ride, but I am blaming that on the trailer's surge brakes (I know elec brakes with the controller are better but you dont find them much in the boating world).

I know it isnt the 6.2L, but since the majority of my miles (30,000+ miles per year) are highway running basically empty, the 5.3L is plenty for me and I think it's was a great tow vehicle for the 5k lbs range. Wouldnt attempt the 9,500 lbs the truck is rated for, but to each his own.

Since the shape of the boat makes it somewhat prone to sway, my question is whether or not LT rated tires will help reduce it. I was running my stock Goodyear Wrangler A/Ts at 39lbs and the trailer is not and will not be equipped with any WD hitch set up. Should I think about going 40-42lbs when towing this setup? I am going to get LT rated tires when its time, but plan on running these for their lifespan unless it will have a BIG impact on trailer sway.

Thoughts?

Do the 6 speed trannys make that much of a difference. I have an 09 5.3 extended cab 4x4 with 3.73 gears and struggles with an 18' Ranger bass boat. I, like you, would not even think about maxing out the tow capacity on this truck. I do not think it would move 8000lbs.

jabo052 · June 11, 2010

I've run stock Bridgestone Dueller At's, Goodyear Wrangler ST's, and Goodyear Wrangler AT/S' on my truck. All the tires were stock P-rated tires with basically the same weight rating. Both sets of Goodyears had much softer sidewalls and you could feel the back-end of the truck swaying a little when towing a car on an open car trailer. The Dueller's didn't have the swaying issue. I just got a set of LT Goodyear Wrangler's in load range C. I haven't towed anything heavy yet, but I haven't felt any sway with just an empty car trailer (~2,100 pounds) on behind my truck.

I've towed with the Bridgestone Dueller A/T Revo's in P and LT and I can say that the LT's are definitely better. I went with the LT's because I spend some time off-road at some of my projects and the LT's are tougher with the rocks, but the truck definitely handles better when I pull my camper.

The LT's make a little more noise and have a slightly harsher ride, but nothing bad. I went through 3 sets of Revo's on my '03 Sierra so it was only natural that I went them on my '10 Sierra All Terrain.

blevenson · June 11, 2010

Do the 6 speed trannys make that much of a difference. I have an 09 5.3 extended cab 4x4 with 3.73 gears and struggles with an 18' Ranger bass boat. I, like you, would not even think about maxing out the tow capacity on this truck. I do not think it would move 8000lbs.

Without the trailer the 6 speed is mush smoother, especially in the stop and go traffic where everyone insists on getting up to 45+ mph and then jamming on the brakes. I have been impressed with the 6 speed (about 12,000 miles on the clock now) in all conditions, but when I hooked up to the trailer it was an instant difference from the 4 sp. 1st gear is a monster, plenty of power (yes I know - its not the 6.2L, we cant all be that special) compared to the 4 speed and the trans is very decisive and smooth using tow/haul mode. I didnt get on it at all since this was the first real load on the truck and I would like to see 500+ miles of break-in with a load, but the truck was very smooth. I cant say enough about grade braking other than it seemed to drive the cars behind me nuts when we were slowing down with no brake lights.... Seriously though, great feature.

Being that its only the 5.3L, when I wanted to change lanes the trans performed flawlessly, quick downshit when needed and smooth. I did use M5 to limit the truck from using the second OD, but I dont know to what effect, other than I didnt get the seemingly high revs that others have reported when taking their foot off the gas. I guess using M5 is the 4 speed habits coming back - No 4th gear unless perfectly flat highway miles...not many of those in the northeast.

I have since spent some time studying the trailer/boat combo and found that the boat was about 4" too far back on the trailer and put the center of gravity between the tandem axles, instead of on the front axle/tongue, which should explain most of my jerky/sway issues. Next time I hook up this combo I will make sure the yard gets the boat positioned right.

Your 18' Ranger Bass Boat sits on a single axle trailer with a GVWR of only 3,725 lbs according to the Ranger Boats website - IMO you shouldnt be having issues with that setup, unless you are looking to set some speed records, or loading the boat down with gear and exceeding the trailer's GVWR. Thats a relatively aerodynamic low center of gravity load and there are guys towing 5,000+ lbs travel trailers with the aerodynamics of a barn with your set up. I have no doubts that my truck could get 8,000+ lbs moving, but I dont think it could control/stop it...

music · June 12, 2010

Your 18' Ranger Bass Boat sits on a single axle trailer with a GVWR of only 3,725 lbs according to the Ranger Boats website - IMO you shouldnt be having issues with that setup, unless you are looking to set some speed records, or loading the boat down with gear and exceeding the trailer's GVWR. Thats a relatively aerodynamic low center of gravity load and there are guys towing 5,000+ lbs travel trailers with the aerodynamics of a barn with your set up. I have no doubts that my truck could get 8,000+ lbs moving, but I dont think it could control/stop it...

I've towed a lot, and pull ~7k lbs loaded camper w/ the 5.3/4-spd/3.73 combo... plus a family of five. It handles solid. Getting up to speed can be a bit slow, especially when pulling out up hill, but I'm no slower than any other heavily loaded truck I've been behind. Stability is all about weight distribution and proper WD hitch when towing a heavy trailer, and stopping *requires* a good brake controller and trailer brakes. No matter what brakes the truck has, they're not going to stop an extra 6k+ lbs easily or quickly on their own.