Towing discrepancy with 6.2l 3.42 rear diff

2017HD · August 16, 2017

I have been towing now since 83 with various sizes of trailers and tow vehicles. I love my last two combos - a 2007HD gasser with a 24' 6000lb travel trailer and my current ride an 8000 lb 31' TT and a 2017 2500HD Dmax. My worst combo was the 24'TT and a 99 4 dr Tahoe. Not only was that combo under powered, it was also very squirrely. This TT was at the limits of the tow rating for the Tahoe. Driving from Portland Or to camp on the coast was a real chore. I was really amazed in the difference the 6.0L 6sp and 4.11 rear gears made (the Tahoe was a 5.7L 4sp, 3.73 rear gears). The only down side was fuel mileage and small tank. I never got to tow the old TT with the Dmax (except to the dealer to trade it in on the new bigger one). But the DMax hardly knows the 31' TT is back there (weight wise) I still have some issues with side winds and passing semis. Mileage with the DMax is around 11-12 towing and 23+ Hy light. Around town the DMax averages 13-14 - depending on how much starting and stopping I do -along with how much lead is in my foot.

I also have to agree with some of the others that if you want to tow a larger TT that is also lightweight then expect the TT to fall apart quicker. If you think about it most all TTs have similar number size and wt appliances and tanks so where did the weight difference come from - structure of course - frames, walls, roofs etc.

elchilero53 · August 16, 2017

I had a 2014 Tahoe Z71 with the HD tow package, a 5.3L, a 6-speed, and a 3.42:1 rear end. We towed a 24' TT with no problems except it was slow on the hills and tended to get hot on a long 7% grade (which we solved by turning the A/C off during the climb). I was right at the limit of this machine's tow capacity. We won't be going any heavier on the TT so the new truck is well suited to this rig. If we did go a lot bigger (greater than 26' length and 7800 lbs TT GVWR), I would go straight to the 3500 with a diesel and skip the 2500 altogether.

Another problem seldom discussed is TT length in relation to the tow vehicle length and weight. Aside from weight, a long trailer in cross winds or windy conditions can get very hairy. It has happened to me and videos available on YouTube show it happening to others as well. Even with anti-sway devices, the ride can be a serious white-knuckle adventure, to say the least.

Blue2500CC · August 17, 2017

Jon,

Welcome!!!

As has been mentioned, a trailers weight quickly adds up. So if at all possible, try to narrow down to a few choices what tt you would like. That way you can decide if the 1500 is enough or not.

One thing mentioned is the listed payload includes a 150lb driver, I disagree with this... Reason is the sticker states: "ALL OCCUPANTS and cargo not to exceed XXXXlbs". The driver Is an occupant of the vehicle. Now in regards to the tow rating (two different rating), there is a 150lb driver and a 150lb passenger if the tow rating is per the new standard. The old tow rating was based one just a 150lb driver, but the payload still did not account for a 150lb driver. BUT, with that said, if you are that close that you're worried if a 150lb driver is included or not in the payload becaUse you are that close to thebrating, you probably need a truck with more payload.

Another thing to watch is the trucks factory mounted receiver hitch tw rating. It is usually the next rating after the payload tinge exceeded, or third after the gcvwr/gcwr.

Good luck shopping!!!

Jonboyslim · August 17, 2017

Great info from everyone here!! I'm leaning toward the 2014 sierra 6.2l.. The owner told me it has a 3.42 but I realized after it has tow mirrors so maybe it's a 3.72.. definitely worth a check in the glove box. Thanks again to everyone who chimed in.. lots of good info and experience here to help!

crankman · August 17, 2017

We have a 6.2 with 3.73 NHT max tow 1500 in our family. If your planning on towing with 1/2 ton that is the ticket. Ours has 4 wheel disc brakes which is a nice benefit when towing. Has the power to pull very well. I would look hard for one before settling for the 5.3. Good luck with your decision

zo6freak · August 25, 2017

With all that said, I have a 5.3 CC 4X4 3.08 with 33" tires and I want to re-gear for towing and overall performance. Should I put 3.73's in or jump to 4.10's and have the confidence???? I've heard people say the 4.10's are too short for a 5.3 6 speed...

Cheers

COHauler · August 25, 2017

With all that said, I have a 5.3 CC 4X4 3.08 with 33" tires and I want to re-gear for towing and overall performance. Should I put 3.73's in or jump to 4.10's and have the confidence???? I've heard people say the 4.10's are too short for a 5.3 6 speed...

Cheers

This has been helpful over the years. Hope this does the same for you.

elchilero53 · August 27, 2017

IMG_2172.JPG

This has been helpful over the years. Hope this does the same for you.

Interesting chart! Looks like it was built for Jeeps with their engines, trannies and rear ends. Doesn't really fit any experience that I have had with my 2014 Tahoe or 2017 Silverado 1500. Any equivalent charts for GMs? Edited August 27, 2017 by elchilero53

COHauler · August 28, 2017

Interesting chart! Looks like it was built for Jeeps with their engines, trannies and rear ends. Doesn't really fit any experience that I have had with my 2014 Tahoe or 2017 Silverado 1500. Any equivalent charts for GMs?

It works, gear ratio's don't change as long as you are 1:1 drive ratio in the transmission. What it states, is that GM gearing sucks in the 1/2 ton trucks. It is for fuel mileage. Now the 4th gear in your truck is still not exactly 1:1, but close enough. Now with some configurations with Max Tow Packages, you can get the 3.73 gear ratio. Going from 3.73 to 4.11s is only 250 rpm.

Do me a favor, the next time you are going down the highway at 65 mph, drop the transmission into 4th gear and see where you are at with the 33" tires. It will be close to the chart.

4.11 gear ratio would do wonders for your truck, that I promise you. The Jeep in my signature has 5.38 gears and it is ok at best in 2wd driving up to 60 mph since the huge horsepower producing I-6 4.0 is still installed and struggles with the 40" tires. The next swap is a LS motor for sure. Now when I kick in the Atlas 4.3 transfer case, all four of the 40" tires can be smoked easily. All about gear reduction.

Now my good friend has an LS3 and 4L65E, 5.38 gear ratio with 40" tires and cruises at highway speeds without much effort. Having a little RMP in the 5.3L motors isn't a bad thing.

Now if I attempted this, I would have to be in 4Lo and hitting the rev limiter, where his TJ was in 4Hi and had the power/wheel speed to keep going.

elchilero53 · August 28, 2017

It works, gear ratio's don't change as long as you are 1:1 drive ratio in the transmission. What it states, is that GM gearing sucks in the 1/2 ton trucks. It is for fuel mileage. Now the 4th gear in your truck is still not exactly 1:1, but close enough. Now with some configurations with Max Tow Packages, you can get the 3.73 gear ratio. Going from 3.73 to 4.11s is only 250 rpm.

Do me a favor, the next time you are going down the highway at 65 mph, drop the transmission into 4th gear and see where you are at with the 33" tires. It will be close to the chart.

4.11 gear ratio would do wonders for your truck, that I promise you. The Jeep in my signature has 5.38 gears and it is ok at best in 2wd driving up to 60 mph since the huge horsepower producing I-6 4.0 is still installed and struggles with the 40" tires. The next swap is a LS motor for sure. Now when I kick in the Atlas 4.3 transfer case, all four of the 40" tires can be smoked easily. All about gear reduction.

Now my good friend has an LS3 and 4L65E, 5.38 gear ratio with 40" tires and cruises at highway speeds without much effort. Having a little RMP in the 5.3L motors isn't a bad thing.

Now if I attempted this, I would have to be in 4Lo and hitting the rev limiter, where his TJ was in 4Hi and had the power/wheel speed to keep going.

That would be 6th gear and 31" tires. I get great mileage and it tows like a champ. Edited August 28, 2017 by elchilero53

COHauler · August 28, 2017

That would be 6th gear and 31" tires. I get great mileage and it tows like a champ.

What would be in 6th gear?

elchilero53 · August 28, 2017

Transmission. I have the 8R90 8-speed. The 6th gear is 1:1 and the tires are 31". With the 3.23:1 rear end that would put the RPMs between 2262 and 2333 on your chart above. I get 2263.7 RPMs for the 3.23:1 rear end in 6th gear at 65 mph.

COHauler · August 28, 2017

Transmission. I have the 8R90 8-speed. The 6th gear is 1:1 and the tires are 31". With the 3.23:1 rear end that would put the RPMs between 2262 and 2333 on your chart above. I get 2263.7 RPMs for the 3.23:1 rear end in 6th gear at 65 mph.

Oh shit. I just noticed that I quoted another person, and you came into the conversation...LOL. Sorry about that.

Now I am in the same ball park. I thought you had the six speed and 3.08 gears.

I would hope your truck tows like a champ with the 6.2L and 8 speed. That is GMs top dog in the 1/2 ton line up.

elchilero53 · August 29, 2017

Oh shit. I just noticed that I quoted another person, and you came into the conversation...LOL. Sorry about that.

Now I am in the same ball park. I thought you had the six speed and 3.08 gears.

I would hope your truck tows like a champ with the 6.2L and 8 speed. That is GMs top dog in the 1/2 ton line up.

That's alright. You had me going for a minute! Too funny.

zo6freak · September 6, 2017

It works, gear ratio's don't change as long as you are 1:1 drive ratio in the transmission. What it states, is that GM gearing sucks in the 1/2 ton trucks. It is for fuel mileage. Now the 4th gear in your truck is still not exactly 1:1, but close enough. Now with some configurations with Max Tow Packages, you can get the 3.73 gear ratio. Going from 3.73 to 4.11s is only 250 rpm.

Do me a favor, the next time you are going down the highway at 65 mph, drop the transmission into 4th gear and see where you are at with the 33" tires. It will be close to the chart.

4.11 gear ratio would do wonders for your truck, that I promise you. The Jeep in my signature has 5.38 gears and it is ok at best in 2wd driving up to 60 mph since the huge horsepower producing I-6 4.0 is still installed and struggles with the 40" tires. The next swap is a LS motor for sure. Now when I kick in the Atlas 4.3 transfer case, all four of the 40" tires can be smoked easily. All about gear reduction.

Now my good friend has an LS3 and 4L65E, 5.38 gear ratio with 40" tires and cruises at highway speeds without much effort. Having a little RMP in the 5.3L motors isn't a bad thing.

Now if I attempted this, I would have to be in 4Lo and hitting the rev limiter, where his TJ was in 4Hi and had the power/wheel speed to keep going.

Okay so i wanted to report back on this. At 65MPH in 4th gear my RPMs are at about 2600. Im thinking the 4.10's would be perfect for my 6 speed and 33"s...