Anyone towing a fifth wheel with Dodge 2500 6.4 Hemi 4x4?

mtofell1 wrote:
The regional differences are funny.... I don't think I've seen a 2WD truck on a lot up here for years :)

I got a 2 WD F250 in the garage but I am a little ways from you. :W

You folks recommending 4:10 and 4:56 rear end gearing have to realize the higher the RPMs you have to use, the lower the gas or fuel mileage you're going to get, especially using a gas engine. The fella with the 6.4 hemi engine is going to be disappointed pulling a fifth wheel trailer. The 6.4 hemi is an awesome engine, but he's going to be using high rpms doing it because the hemi engine gets its power and torque with high rpms. It's not designed for low end torque which is what is required for hauling big loads also, I remember back in the 70's, my then wife's bro in law was nuts about building racing cars and his car was a dodge hemi big block engine. He had installed 4:11 rear gears in it and one day I passed his wife driving it. She had the engine rpms maxed out and was only going 60 mph. His car was really quick off the line but top end speed really sucked. I said all that to say that 3:73 rear gears should be plenty with what he's got. My truck is a '99 2500 4X4 5-speed Dodge with a V-10 gas engine and 3:55 rears and I pull a 29' fiver. I don't have any trouble pulling 6% grades but I should have bought a diesel. A head or side wind catches that tall camper and really drinks my gas. I don't care how big a gas engine is, it just doesn't have near the torque a diesel does. This is all just my humble opinion and it's really none of my business what anybody does with their stuff. I wish that fella all the luck in the world, but I wouldn't do what he wants to do with a hemi. It's made more for racing than anything else. He could beat my V-10 in a quarter mile race, but I can hook on to the back of his hemi and pull him all over the place. I pulled a semi out of the mud a couple of times.

The regional differences are funny.... I don't think I've seen a 2WD truck on a lot up here for years :)

mtofell1 wrote:
I worried when getting my new 5th wheel a couple months ago. My truck is a 2014 2500 w/6.4 Hemi 3.73 gears. My 5th wheel is a Keystone Hideout and was surprised to end up with about 8" of clearance. I think some RV manufacturers are catching up with the height of these new trucks and building the 5th wheels accordingly. The worst combo would be an older 5th with a newer truck. So, you might check out some other brands of 5th wheel and you will probably be okay.

Now for the weight thing. Your max weight should be 12,500# with a payload of 3000#. I have a 12,000# GVWR 5th that, once loaded, puts me right at my payload max. The 5th overall weighs about 10,500# and leaves me about 1000# of GCWR (combined truck and trailer max is 19,500#).

GCWR:
Truck - 7000#
People, 5th hitch, etc. - 1000#
5th - 10,500#
Total = 18,500#

Payload:
Truck - 7000#
People, 5th hitch, etc. - 1000#
Pin weight from 5th - 2000#
Total = 10,000#

The truck handles it fine as is but I'm likely going to get some rear airbags as it bounces a bit excessively over uneven roads at times. Nothing terrible. I'm also thinking about re-gearing with 4.56s. The same truck with the 4.10s is rated for an additional 3000# of GCWR (payload stays at 3000#). Aside from towing better I've also heard good things about the truck as a daily driver with the different gears. The only downside is I'd be turning about 400RPM higher on the freeway. I can't remember exactly but I think it's like 2200RPM vs. 1800RPM at 70.

Edit: I see the OP is in Florida - I'm out west with lots of hills so. The 3.73s would be fine in flatter areas.

It's the 4x4 that is making it so tall. This year's trucks seem to run tall even with stock tires 60". They are 18". Our work truck is plum wore out so we are upgrading it to a 2500 5.7, 3.73 2 wheel drive which should do fine with the light weight models we are looking at.

Thanks for all of your input. I think we have solved the problem with a 2500 Dodge 2 wheel drive which sits on 56" high. It should work out fine.

I worried when getting my new 5th wheel a couple months ago. My truck is a 2014 2500 w/6.4 Hemi 3.73 gears. My 5th wheel is a Keystone Hideout and was surprised to end up with about 8" of clearance. I think some RV manufacturers are catching up with the height of these new trucks and building the 5th wheels accordingly. The worst combo would be an older 5th with a newer truck. So, you might check out some other brands of 5th wheel and you will probably be okay.

Now for the weight thing. Your max weight should be 12,500# with a payload of 3000#. I have a 12,000# GVWR 5th that, once loaded, puts me right at my payload max. The 5th overall weighs about 10,500# and leaves me about 1000# of GCWR (combined truck and trailer max is 19,500#).

GCWR:
Truck - 7000#
People, 5th hitch, etc. - 1000#
5th - 10,500#
Total = 18,500#

Payload:
Truck - 7000#
People, 5th hitch, etc. - 1000#
Pin weight from 5th - 2000#
Total = 10,000#

The truck handles it fine as is but I'm likely going to get some rear airbags as it bounces a bit excessively over uneven roads at times. Nothing terrible. I'm also thinking about re-gearing with 4.56s. The same truck with the 4.10s is rated for an additional 3000# of GCWR (payload stays at 3000#). Aside from towing better I've also heard good things about the truck as a daily driver with the different gears. The only downside is I'd be turning about 400RPM higher on the freeway. I can't remember exactly but I think it's like 2200RPM vs. 1800RPM at 70.

Edit: I see the OP is in Florida - I'm out west with lots of hills so. The 3.73s would be fine in flatter areas.

I had to do an axle flip on my fifth wheel and it helped. I may go to larger tires on it as well but the axle flip seemed to get it pretty close to level. You can also take the trailer to a welding shop and have them put on longer hangers.

MFL wrote:
There are several ways to raise the FW to fit the truck. The best is to add a subframe, made from square tubing. They do make blocks to go under the trailer springs, but I would not go more than an inch or two, using this method. You may be able to change FW tire/wheel size if you have enough wheel well clearance. There is a correct track system that will raise the trailer also.

IMO, it does not matter all that much to be a little nose high. I would say 2 inches or less.

Another thing to consider with the taller tires on the truck, is gearing. Even though the tall tires only raise the truck an inch, they can change your overall gearing from 3.73, to closer to 3.55. For towing purposes you'd be better off with the 4.10 ratio.

Jerry

I used the 2" blocks on both my toy haulers...no issues but I would recommend using larger diameter u-bolts when putting it back together. They are available through a custom bolt company and not very expensive either.

I had towed my Open Range 337RLS for over 6 years with a 2005 Dodge 2500 4x4 with the 5.7 Hemi and 3.73 gears with no trouble. It took me where ever we wanted to go. Probably towed close to 40000 miles. The Dodge was getting some mileage on it and I had the chance to get a great deal on a used '14 Chevy crew cab with the 6.0 and 4.10 gears so I traded. Every now and again I see the Dodge around still going strong.
I know this does not say anything for the 6.4 but if I could do it with the 5.7 the 6.4 should be even better. I had looked at the Dodge with the 6.4 but couldn't get a great deal. Good Luck and Happy Camping.

There are several ways to raise the FW to fit the truck. The best is to add a subframe, made from square tubing. They do make blocks to go under the trailer springs, but I would not go more than an inch or two, using this method. You may be able to change FW tire/wheel size if you have enough wheel well clearance. There is a correct track system that will raise the trailer also.

IMO, it does not matter all that much to be a little nose high. I would say 2 inches or less.

Another thing to consider with the taller tires on the truck, is gearing. Even though the tall tires only raise the truck an inch, they can change your overall gearing from 3.73, to closer to 3.55. For towing purposes you'd be better off with the 4.10 ratio.

Jerry