I am looking to purchase another tow vehicle. I used to own a 2006 duramax diesel with the allison. My towing requirements are not as far in range now but the weight is still arounnd 9,500lbs. I am considering a 8.1 or 6.0 for the job. I understand the 8.1 gas has the allison transmission while the 6.0 doesn't. First question- anyone have experience with this type of weight with either configuration, secondly if it is the 6.0 did you ever expereince any transmission issues. thirdly has anyone use a 6.0 with this weight and changed to a steeper gear, 4.10 or 4.56? Thanks for the help.


Kelly

 

I would recommend the 8.1 if you can deal with the gas mileage. The 6.0 would probably get the job done, but not near as comfortably as the 8.1. I tow around 6000 pounds with my 6.0 and I wish it has a little more. I am getting 4.10 gears installed to replace my current 3.73's. I'll let you know how that helps. Just my opinion.

 

I am new to this forum and actually just posted a question about my own new 6.0 HD. My question was about my engine seeming to rev too high at higher speeds. I was informed to check my gear ratio and as it turns out I do have 4:10. For help with your question, I can tell you that I tow around about 7K lbs in a trailer of tools quite regularly for my job and just today towed a bobcat excavator around town and was amazed at the eaze of ride/tow. I am more than pleased however I am unsure of any transmission faults as I only have about 31k miles on the truck.
...If there were just anything I could do about the gas mileage while I am not towing (10mpg starts to hurt the wallet.)

 

the 6.0 with the 4l80 and 4.10 gears is a good combo for light to moderate towing. however, 9500lbs on anything but flat ground is going to put some hurt on the 6.0. i would suggest the 8.1. their mpg should be around the same pulling the same weight.
the 8.1 does have a tendency to use oil.

the 8.1 ususally has the allison and a 3.73 gear ratio and is either a 5speed in pre 06 models or a 6 speed in 06-07 classics.

the 6.0 makes its peak tq around 4000 rpm so dont be afraid to let the revs get up some.

 

I use a chevy 3500 dump truck every day with a 6.0 in it. i know the dump body is heavier than a regular pickup truck but with a skid steer on the back with a couple buckets it could definately use a lot more power. It also has the 4:10 rearend and it is a dog of a truck, even when empty

 

The 6.0L will have the 4L80E transmission. The 4L80E is a beast of a transmission but put a big transmission cooler on it. That transmission DOES NOT like HEAT. Look at a B&M super cooler atleast 22,000 GVW and a bigger pan. A derale cooling tube pan is what i use and it holds an extra 3 quarts of fluid. The 8.1L will pull down the side of a barn. The allison transmission is nice and will aid in stopping anything you tow. However around 8mpg is all you will get towing anything and maybe 10 on the highway empty. Just an opinion based on experience.

 

I have a 01 2500 HD ext. cab with the 6.0. I am not sure what tranny it has on it but the truck has the towing and plowing package. I tow a 10k lbs 26' travel trailer with it. With the full family, bed full of gear and some firewood and the trailer it tends to downshift quite often even when going up slight grades. I have taken it to the Black Hills and it got about 7mpg both ways. The truck get about 11 average in the city - 7 or 8 pulling the camper.
How does one go about finding the ratio and what kind of cost is it to change to the better ratio if needed?

 

look in the glove box at the rpo codes. gt4=3.73, gt5=4.10.