2500 Outdoorsman

[Streemly]

I recently purchased a large 5th wheel RV. To pull it with my 2500 Diesel I installed airbags. The truck pulls the RV nicely, but as I learn to run the numbers on my towing capacity, I still come up short.

All that to say; I'm considering upgrading my gear ratio from 3.42 to something around 4.10 or higher to increase my towing capacity in leu of buying a larger truck.

Your thoughts and who do you recommend I get to do the upgrade should I decide to do that?

Thank you for your help with this.

 

[Neil E]

Payload with the diesel is what's going to kill you. Not sure if there is anything to do to help with that.

 

[dhay13]

Changing gear ratio will not change the legal maximums. It might feel better and feel like it has more power but your maximum is still what is was from the factory. Same with air bags. They might make it feel better but do not change the towing capacity.

If you give more details like what TT it is, with weights, you should get some good answers. But in general with a 2500 Cummins you are limited to about a 10,000lb 5th wheel maximum due to payload limits. The weights you should NEVER exceed are your GRAWR and your GCWR. These can be dangerous. Overloading beyond payload isn't quite as dangerous if you stay under those other two I mentioned.

Example, My son had a 2018 2500 6.4 that he towed his 2018 Grand Design Imagine 2670MK with. CAT scaled the trailer weighed 8100lbs and the truck with tongue weight (and loaded with us in it) was 9100lbs. The Cummins weighs about 900lbs more than the 6.4 so if my son's truck was a Cummins he would have been right at his trucks maximums on payload (10,000lb GVWR).

Here is his weigh slip. And don't forget to add the 1100lb tongue weight back to the trailer. Take your setup to a truck stop with a CAT scale and weigh the truck by itself (with everyone and everything in it) then hook up the 5th wheel and weigh it again.

 

[crash68]

How big of a fiver(weight/length)?
Unless your in dually territory, changing to 4.10 with a CTD under the hood isn't going to do much for you. Part of why you regear is to raise the rpms of the engine to get into the torque band, given the CTD peak torque is 1600 rpms vs the Hemi at 4K rpms.

 

[tron67j]

A diesel in a 2500 pretty much moves you out of many 5th wheels, except the lightest ones. Gearing will only reduce your mileage at this point and do nothing to fix numbers. Your only options are a lighter trailer or a 3500 or bigger truck, depending on the numbers you have ( pin weight of fully loaded trailer, hitch system weight, + all the people and gear you throw in truck subtracted from payload capacity on door sticker). Good rule to consider is you run out of payload before you run out of towing capacity (remember, trailer towing capacity and payload capacity are 2 different things). Good luck.

 

[2020PW]

Sell it and upsize.

 

[68PowerWagon]

I recently purchased a large 5th wheel RV. To pull it with my 2500 Diesel I installed airbags. The truck pulls the RV nicely, but as I learn to run the numbers on my towing capacity, I still come up short.

All that to say; I'm considering upgrading my gear ratio from 3.42 to something around 4.10 or higher to increase my towing capacity in leu of buying a larger truck.

Your thoughts and who do you recommend I get to do the upgrade should I decide to do that?

Thank you for your help with this.

I have some 3.73's I would sell pretty cheap but then you would still have to pay labor on the install. They have just over 50k on them. That's when I re-geared my gasser to 4.56's

 

[Bigdaddy]

3500. Gears what help the payload, it is what it is on the sticker on the door.

 

[Streemly]

Sell it and upsize.

Exactly what I did. Thanks