Towing With 2011 1500 5.3 And 6speed Questions

Zale · June 12, 2011

I have a new 2011 1500 crew-cab with the 5.3, 3.42 gears, and 6 speed transmission. I am wondering about towing with this truck. I have an eighteen foot car trailer which I pull a small utility tractor on and am thinking about pulling some four-wheelers to the mountains. Should I leave the shift lever in D and use the Tow/Haul mode or should I lock out sixth using the manual? What is the best way to tow with this rig.

I question whether this is as much truck as my 2005 with the 5.3, 3.73 gears, and 4speed auto was. It dont seem like it has as much power.

What is everyone pulling with theirs and your opinions. Thanks....

8.1HD/ALLISON · June 12, 2011

I would think the truck would handle that fine. I have heard others comment that towing with the six speed is great, compared to the old 4 speeds. I would think you would want to lock out 6th manually and use tow haul, BUT I would read up in the owners manual to be sure.

Rat4go · August 9, 2011

Leave it in D, and put it in Tow/Haul for most of the driving. Going down a big grade, either let the grade braking feature downshift for you, or do it yourself in M. If you're on really rolling terrain, maybe you pull it into M5 or M4 to keep it from shifting a lot, but it's not like the old 4-speeds that had issues with running in D and needed to be pulled down a gear to get 'em to live.

wavery · August 9, 2011

I have a new 2011 1500 crew-cab with the 5.3, 3.42 gears, and 6 speed transmission. I am wondering about towing with this truck. I have an eighteen foot car trailer which I pull a small utility tractor on and am thinking about pulling some four-wheelers to the mountains. Should I leave the shift lever in D and use the Tow/Haul mode or should I lock out sixth using the manual? What is the best way to tow with this rig.

I question whether this is as much truck as my 2005 with the 5.3, 3.73 gears, and 4speed auto was. It dont seem like it has as much power.

What is everyone pulling with theirs and your opinions. Thanks....

I think that what you may be noticing between the 2 trucks is the difference in gear ratios. You just won't have as much umph, from a stop but once you are rolling, the 6spd should more than compensate.

dwhitton · August 9, 2011

I tow 8000lbs/ 33ft Travel Trailer with mine. no problems. I keep in D and it spends most its time in 5th.

Tranny temps around 85 - 95 c (185 - 205 f) Fuel around 9.5 mpg though (maybe because my trailer is a 33 ft brick)

A good WD hitch and some rear suspension support (timbren SRS or similar) if your tongue weight high, and away you go.

Happy towing.

Stevens03 · August 9, 2011

6-speed trans with 3.42 gears is like having 4.56's in a 4-speed. You won't have any troubles

crankman · August 10, 2011

you should be fine in D with Tow Haul on, an 18ft trailer with a tractor would not even be a challange for it. My son's 08 5.3 3.73 4spd could do that with out a hitch(no pun there) and you can to with that 6speed tranny.

APT · August 10, 2011

I would think you would want to lock out 6th manually and use tow haul

I agree.

kdixer · August 10, 2011

6-speed trans with 3.42 gears is like having 4.56's in a 4-speed. You won't have any troubles

Only in 1st gear. 2nd thru 5th is pretty comparable to a 4spd 3.73 combo.

Sometimes the 6spd 3.42 combo feels sluggish because it short shifts out of 1st. But with a load and tow/haul activated it will wake up pretty good. My advice would be to just experiment and use whichever method you prefer. If it shifts alot you can use manual mode. I would probably use tow/haul just because the 6spd tries to go to 6th as much as possible.

APT · August 11, 2011

6-speed trans with 3.42 gears is like having 4.56's in a 4-speed. You won't have any troubles

Only in 1st gear. 2nd thru 5th is pretty comparable to a 4spd 3.73 combo.

The first 4 gears of the 6-spd/3.42 have more torque (except first is slightly less) than the old 4-spd/4.56. See attached. It would not surprise me if GM programmed the trans to start in second gear most of the time.

kdixer · August 11, 2011

6-speed trans with 3.42 gears is like having 4.56's in a 4-speed. You won't have any troubles

Only in 1st gear. 2nd thru 5th is pretty comparable to a 4spd 3.73 combo.

The first 4 gears of the 6-spd/3.42 have more torque (except first is slightly less) than the old 4-spd/4.56. See attached. It would not surprise me if GM programmed the trans to start in second gear most of the time.

It really all comes down to how you want to look at it. I mean if you added 2 gears to the 4spd, where would you add them? You cannot say that the 1st 4 gears have more torque unless you would intend for the 2 aditional gears to the 4spd to be 5th and 6th.

For comparison purpose I tend to look at the 6spd as a 4spd with the addition of a granny low and an additional overdrive. And when you look at it like this, 1st gear provides more torque but the 4spd does not have the granny low to compare to. 2nd, 3rd, 4th and 5th have more torque than 2nd, 3rd & OD on the 4spd, but the higher the gear the less the difference. So saying it is equivelant to 4.56 is not exactly accurate IMO. And of course 6th has the least torque but again there is no gear on the 4spd to compare to.

But the overall driving experience is similar to a 4spd with 3.73 gears.

I personally have never felt the truck start in 2nd. It has always pulled out in 1st gear.

APT · August 11, 2011

You can look at it however you want. The facts are the you get more wheel torque (did you look at the attachment above?) in the first 5 gears with 3.42 than the 4-spd with 4.10s. No only do you get a "granny" first gear, each gear spacing is closer together. That means the engine stays closer to the desired powerband and/or does not need to spin as high to create the needed power before upshifting. The taller overdrive gets that 21mpg GM likes to advertise.

A numerically lower gear ratio means less torque, not more.

xPosTech · August 11, 2011

I will stay with my 6 speed 3.42. And if anyone wants to keep their 4 speed 4.56 or 4.10 or 3.73 I won't try to convince them otherwise. But I don't make a living towing, either.

But I still wish I had a Duramax/Allison.

Just couldn't afford/talk myself into it at the time. $50K was a bit different than $30K.

kdixer · August 12, 2011

You can look at it however you want. The facts are the you get more wheel torque (did you look at the attachment above?) in the first 5 gears with 3.42 than the 4-spd with 4.10s. No only do you get a "granny" first gear, each gear spacing is closer together. That means the engine stays closer to the desired powerband and/or does not need to spin as high to create the needed power before upshifting. The taller overdrive gets that 21mpg GM likes to advertise.

A numerically lower gear ratio means less torque, not more.

Like I said, it depends on which transmission gears you want to compare. I am well aware of how gears function and the mechanical advantage they provide. But the 6pd shifts thru them really fast under normal acceleration. That is why the driving experience is comparable to a 4spd 3.73 combo. Towing is a different story. I am not arguing the point that there is more mechanical advantage from the first 5 gears. I love my 6spd transmission. But saying it is equal to a 4spd 4.56 combo is a blanket statement that just is not true. Mainly because the comparison is invalid in the 1st place, it is apples to oranges. Why in the world would you be comparing the 1.15 4th gear to the OD gear in the 4spd.

And from a performance aspect there is not a huge difference between the two either. The advantage the low closely spaced 6spd gearing provides is lost in the time it takes to go thru the numerous shifts. Especially with the stock tuning. With a custom tune, the 6spd 3.42 combo is good for nearly a second faster 0-60 time over the 4spd 3.73 combo. But without a tune they are pretty darn close.

music · August 13, 2011

Don't forget the torque converter. These aren't manual transmissions, so straight-up gear ratio comparisons are "just for a rough check". The TC amplifies torque more for a "long" gear than it does for a "steep" gear. I don't know the exact values between the two, but I'm certain that the TC is more active on the 4-spd, especially when cruising (4th locked / 4th unlocked up a grade)... and the 6-spd is more efficient since it doesn't use the TC as much (either starting out, or when cruising). The TC can easily double hydraulic torque multiplication from a standing start. The longer the gear, the greater the "slip", and the greater the multiplication.

Edit: To the OP... I would personally lock out the higher gears if it's shifting there in t/h. I pull in "3rd" with mine, so I'd probably use "4th" on the 6-spd, except in pretty flat / low wind conditions.