Gear Ratio Change?

[CodeMan]

In response to a lot of posts here, I indeed have a half ton truck. Pulls my 22mkse (4300lbs UVW) like a champ. I referenced the owner manual and noticed under towing that it stated that 3.08 gears had a capacity of 6100 where 3.42(I realize my typo in the original post) gears had a capacity of 9100. Hence the curiosity.

[bikendan]

Originally Posted by CodeMan

In response to a lot of posts here, I indeed have a half ton truck. Pulls my 22mkse (4300lbs UVW) like a champ. I referenced the owner manual and noticed under towing that it stated that 3.08 gears had a capacity of 6100 where 3.42(I realize my typo in the original post) gears had a capacity of 9100. Hence the curiosity.

As was said, just changing the rear end gearing doesn't give you the 9100 capacity. There's more involved that that alone.

[Qwkynuf]

Originally Posted by ARhappycamper

Wrong. You cannot increase the CCC (payload) of any vehicle by modding.

This is not strictly accurate. You cannot increase the GVWR by modding. That is an absolute fact.

The CCC (payload) is a derived number - literally the actual (curb) weight of the truck subtracted from the maximum weight (GVWR) that the truck is allowed to be.

So, you *can* increase payload, but only by decreasing the weight of the truck. If you want to take your bed off, and stash it behind your father-in-law's barn, then BOOM - you just gained 300-400lbs of payload. You could take out your 8-way power adjustable driver and passenger seats and replace them with the manual slide-y kind and gain another 100lbs or so. You get the idea.

The flip side of that is that everything you add *into* or *onto* your truck (running boards, tool box, bigger wheels and tires, steer horns mounted on the hood like Boss Hogg) those all reduce your available payload, pound for pound - all the way down to the air freshener and fuzzy dice hanging from the mirror.

[BigH]

Originally Posted by Cowracer

Yes they do. And they also offer the EXACT SAME truck with a 10K GVWR. The reason is, commercial users (landscapers, construction, etc) would fall under DOT regs with a 10,001 and above GVWR and they usually don't want to have to mess with everything that goes with that.

Order a GM 2500 with the C7A RPO code and it comes with a 10K sticker (rating). Check the C7G box, and you get 10,600. Exact same truck. Not a single washer has been changed.

Its all bureaucratic, not engineering.


Tim

Originally Posted by Cowracer

The "sticker on the door" on 3/4 ton trucks is artificially held to under 10K GVWR to keep them in Class 2 and has no real correlation to real world capabilities.
Tim

This is what you said ^...a blanket statement that is false. 3/4 ton trucks are not limited to under 10k. Period. Are there configurations that you can get a 250/2500 or 3500 series truck stickered to under 10k? Yes. My last truck was stickered as such and it had the smaller axle housing -not more capable than the sticker. Period.

Not that the current HD trucks from GM are a great example because they may actually be more capable with just wheel and tire mods but how do you know for sure? If you play with builder on a GM site, you will find the higher than 10k GVWR 2500 series trucks actually have different wheel/tire combo for one thing. Who knows if they changed anything else, such as a frame rail thickness? Ford doesn't tell you when you buy a different configuration that you can get a thinner or thicker frame.

Folks want to do everything they can to make a 'whatever' series truck have a greater capacity than the sticker and the facts are simple. Both Ford and Chevy have used different frames, axle housings, wheel/tire combos and more over the years at different GVWR within the same series of truck. They have also been the same minus small things like just spring rates and wheel/tire combos.

Splitting hairs to show that an 'artificially' lower sticker is available does nothing but enable ignorant folks to overload their truck because it isn't usually 'artificial'... like my last HD.

[moose074]

So I am going to say yes, you can but before people go all crazy, just read . Many people say that tow capacity is biggest lie out there because you will run out of payload capacity way before. Since the op stated he would go from 6k to 9k and has a 1/2 ton and he states towing capacity I believe in original post. Then yes but if one reads tow standard it’s more performance based to set a standard vs engineering based to find failure or safety problems. One such test is the acceleration test at around 11% incline it’s either timed or you have to reach a certain speed. It’s not did the truck make it it’s did it meet the acceleration requirement. So yes changing the gears would allow you to meet tow standards but that’s not a legal thing it’s a bragging thing

[ARhappycamper]

Would be very rare for the same number on the yellow CCC sticker on 2 separate trucks.

[SailorSam20500]

Originally Posted by ARhappycamper

Would be very rare for the same number on the yellow CCC sticker on 2 separate trucks.

I'll disagree with that. Around where I live, dealers often order a slew of identical trucks changing only the color. No reason they would have different CCCs.

[camper_Lucy]

Originally Posted by SailorSam20500

I'll disagree with that. Around where I live, dealers often order a slew of identical trucks changing only the color. No reason they would have different CCCs.

X2 - Dealers do the same here, not uncommon (pre-covid)to walk on a lot with 10 identical units different colors same CCC sticker.

[Boomerweps]

Wow. A lot of sidetracking going on.
Did not see anyone stating an increase in TV Load capacity or GVWR from changing gears. That idea was never challenged.
Changing rear gearing WILL sometimes increase factory towing capacity. Of course, load capacity will not change and likely be the limiting factor.
BUT, using Ford as an example (because I have several of their Towing Guides downloaded), you cross reference your truck's specs to determine the GCWR and resulting Tow Capacity with the gear ratio as a primary factor for a given wheelbase and engine.
Ford, unlike current GM, does not have a separate towing sticker on the driver door frame.

[MR.M]

My 2019 2500 double cab LB is 14,100 tow rating and GCWR 21,100 with the 4.10 gearing the same truck with 3.73 is 9600 tow and GCWR of 16600 . so is the rear axle smaller or is it just the gearing that makes the difference to protect engine and tranny . My truck does not show a GVWR on the door sticker just tires and payload . in glove box shows a slide in truck camper being max at 1981 lbs that's it

[Boomerweps]

Originally Posted by MR.M

My 2019 2500 double cab LB is 14,100 tow rating and GCWR 21,100 with the 4.10 gearing the same truck with 3.73 is 9600 tow and GCWR of 16600 . so is the rear axle smaller or is it just the gearing that makes the difference to protect engine and tranny . My truck does not show a GVWR on the door sticker just tires and payload . in glove box shows a slide in truck camper being max at 1981 lbs that's it

I believe you are mistaken. The (usually) yellow load Capacity sticker has the factory tires and Load Capacity on it. The white required by the federales door sticker with the axle capacities, VIN, build date, etc. also lists the vehicle GVWR.
The GCWR is not listed on either of those stickers but recent years GM trucks have an additional towing sticker that list the specific truck towing related capacities. All examples I’ve seen had prismatic “GM” all over and marked “trailering information.

[BigH]

Originally Posted by MR.M

My 2019 2500 double cab LB is 14,100 tow rating and GCWR 21,100 with the 4.10 gearing the same truck with 3.73 is 9600 tow and GCWR of 16600 . so is the rear axle smaller or is it just the gearing that makes the difference to protect engine and tranny . My truck does not show a GVWR on the door sticker just tires and payload . in glove box shows a slide in truck camper being max at 1981 lbs that's it

You didn't state the make but those look like GM 6.0 numbers to me.

In 2017 that configuration would have had the same rear axle housing in 3.73 or 4.10's. I can't say for sure on your 19 truck even though it is the same model as the '17 because manufacturers do strange things (especially getting near to a new model year...excess parts and whatnot) but I'd be willing to bet your rear axle housing was not available in the 3500 same as it was with the '17 trucks.

The lower numbers (GCWR and tow rating) didn't have anything to do with protecting the driveline. You can hold either of those combinations to the floor all day and never get the temps up. The 6.0 wasn't the most powerful but it was/is sturdy and reliable.

The reason for the lower numbers was due to performance testing (SAE J2807).

We were camping out west when my mom took a turn for the worse. We rushed back in hopes of seeing my mom before she died. There was a strong headwind that had my foot on the floor or very near the floor for hours with my 6.0/4.10's. The motor temp never moved and the transmission never got above 185.

[Rockwood Travelers]

We have a 2009 Ford F-250 Super Duty 4x 4 crew cab long box that we bought new off the lot. It had a 3.73 from the factory. I regeared it to a 4.56. Bought the Yukon gears from Randy's Gears out in Everett, WA. I am capable of installing the gears but due to time restraints and lack of specialty technical equipment needed I had a very reputable independent shop do the install. Bottom line was $2,100.00, gears & labor. Best 2 grand+ I ever spent on a performance modification. Our truck went from towing like a mundane so-so unit to a towing beast!! There is no more effective towing performance modification as a lower gear ratio!!

Do it. You won't be disappointed!!

[jaymz]

Originally Posted by BigH

This is something that gets repeated by folks who don't know what they are talking about. Complete hogwash sir...

There is no 10k limit on 250/2500 series trucks. Both Ford and GM offer that class vehicle above 10k. If you look at the different configurations Ford has above 10k in that class, it looks like Ford would disagree with your last sentence as well.

He knows what he’s talking about. My 2019 Jeep Wrangler has a max towing capacity of 3500lbs in the US. The identical Wrangler in Europe has a max towing capacity of 5000lbs. The difference is 100% related to the “rules”. There’s no reason to believe that the rules are any different for any other manufacturers vehicles.

Max towing capacity is an arbitrary number based on the “rules” and the physical capabilities of a particular vehicle.

[Mikec557]

Originally Posted by CodeMan

Was looking to upgrade the camper and found that my 18 silverado with stock 3.08 gears will allow me to tow up to 6100lb. If I had 3.43 gears, then I could tow up to 9100lbs. Has anyone done this? I often see people with 1500/F150 trucks towing campers that seem to be way outside the limits.

We had a 2018 Silverado 1500 with the 3.43 rear diff. Loved the way it pulled, except long mountain grade. The 5.3 gasser would run about 4000 rpm. But on the rest of the terrain it was awesome.

But being able to pull 9000 instead of 6000lb wasn't the issue. It was both the low cargo carrying capacity and GRAWR that was the serious downer. And the heavier the trailer you can pull makes the tongue weight heavier and heavier. Thus exceeding the CCC and GRAWR.

[rcknrbn]

I did this a few years ago on a 2004 F150, not with the intent on believing I was gaining towing capacity but merely to make what I was already towing more comfortable. The factory setup was 3:55 gear ratio and I regeared to 4:10. It was a 4wd so it cost more than a 2wd.

The end result was a bit of a double edged sword. The new setup dropped my mpg by a solid 2 mpg overall! However, it made a huge difference in what I was towing. Working off memory but I believe I was towing about 6500lbs. Was maybe a little less. I just didn’t like the way the 3:55 towed in the mountains.(Smokies).

I can’t imagine towing with 3:08, that sounds like it could be painful!

Just adding my $.02 from experience. Find a good powertrain shop and talk to them.

[moose074]

Originally Posted by Rockwood Travelers

We have a 2009 Ford F-250 Super Duty 4x 4 crew cab long box that we bought new off the lot. It had a 3.73 from the factory. I regeared it to a 4.56. Bought the Yukon gears from Randy's Gears out in Everett, WA. I am capable of installing the gears but due to time restraints and lack of specialty technical equipment needed I had a very reputable independent shop do the install. Bottom line was $2,100.00, gears & labor. Best 2 grand+ I ever spent on a performance modification. Our truck went from towing like a mundane so-so unit to a towing beast!! There is no more effective towing performance modification as a lower gear ratio!!



Do it. You won't be disappointed!!

I see your 4:56 and raise you a 22-1 ish

Honestly the gearing in my Tundra is why I still miss it but the HO Cummings makes it easier to forget

[BigH]

Originally Posted by jaymz

He knows what he’s talking about. My 2019 Jeep Wrangler has a max towing capacity of 3500lbs in the US. The identical Wrangler in Europe has a max towing capacity of 5000lbs. The difference is 100% related to the “rules”. There’s no reason to believe that the rules are any different for any other manufacturers vehicles.

Max towing capacity is an arbitrary number based on the “rules” and the physical capabilities of a particular vehicle.

Arbitrary? Nope. Look up SAE J2807.

The rules are different in Europe and not based arbitrarily. They tow with less tongue weight and the speed limit while towing is strictly limited. Research the differences and you can even find math equations for the justifications.

Your Jeep tows less here because it can't handle a higher tongue weight. It could be structural but most likely it can't pass the handling test at the SAE's required tongue weight for the European trailer rating.

[Tacky]

Originally Posted by CodeMan

Was looking to upgrade the camper and found that my 18 silverado with stock 3.08 gears will allow me to tow up to 6100lb. If I had 3.43 gears, then I could tow up to 9100lbs.

As others have mentioned, there is a lot more to it. My 18 Silverado, with the max tow 5.3 package, has a significantly larger rear axle and heavier springs, basically a 2500 series rear end, to get the 9000+ tow capacity. An additional issue that you would have to deal with is reprogramming modules. Everything that uses speed signals, including engine, transmission, ABS and more, will have to be reprogrammed for the new axle ratio. I do know that GM will not release programming for different axle ratios, so you will have to go aftermarket. If you have any remaining warranty, the aftermarket programming will probably void it. If you need more tow capacity, I would suggested trading in for a heavier duty truck.

[upflying]

Towing while overloaded (TWI) is fine until a crash happens. Sometimes you can get away with it and sometimes you can't.
You are taking on additional risk and changing gear ratios wont change the cargo capacity and tow rating on your door sticker.
Back in the day, I towed a 23' Fleetwood TT with a '79 Ford F100, regular cab shortbed with no tow package and a 302 V8. It towed great until I needed to stop.