Single rear axle vs. tandem axle towing

[Bottomland4x4]

I'm looking at a renegade motorhome and a renegade toterhome. The toter has 22 foot living quarters and is a tandem rear axle. The motorhome is a 28 foot conversion with a single rear axle. I will be towing around 22,000 lbs with either one. What I was wanting to know is how close is that to maxing out the single axle motorhome. Renegade says it is rated to tow 30,000, but I want to know real world experiences.

Right now towing 21,000 with my 16 foot single axle toter is no problem, I closely watch the air bag gauge. empty, it is 35psi, and loaded it only goes to 50psi. Also the rear axle hardly gets to 180-190 degrees. So I think my tongue weight is really good, I just wonder how the larger motorhome would do?

 

[ChiefMechanicMark]

The tag in the drivers door should have your axle weight ratings as well as your Gross Vehicle Weight Rating (GVWR). This is the best way to check out a vehicle for your needs.
Your air bag pressure is not really letting you know how much weight you have sitting on the axle and tires.
There is an onboard scale system available (Log Trucks use them a lot since there is no scale in the woods.). It is a block of material that is placed between the log bunks and the frame of the truck. As weight is applied it sends an electrical signal to the computer which has been calibrated when the system was installed to read out actual weight of the vehicle as well as the weight added to the vehicle.
Personally I like two drive axles for purposes of traction when needed, I know the suspension and tires are going to handle anything I throw at it and last...Go big or stay home!!

 

[porky69]

Using air pressure in the suspension to gauge axle load is actually fairly accurate once you have a reference point, for example on every Peterbilt I drove with Low Air-leaf suspension 72psi is 17,000kg (37,500lb)(which is Canadian tandem drive axle max weight), I used to haul grain/feed/fertilizer from farms in the middle of nowhere and could get my gross weight within +/- 500lbs if I had fairly flat ground.

If you really want to get exact there are specially calibrated air gauges that are tuned to your unit and can get you within +/-100lbs.

 

[Bottomland4x4]

I don't really use the air gauge to weigh out the truck, I just use it to adjust the load on the hitch. I can move my truck around on the trailer, and it seems to ride and pull the best around 45-50 psi. Here is a picture, it's kinda hard to see but the truck on the trailer weighs 10,500.

 

[Bottomland4x4]

Here is the pic.

 

[ChiefMechanicMark]

Porky69,
I guess I never thought about someone using airbag pressure to weight comparison, but now that you mention it, if you took the time to figure the math I guess there is no reason you would not be able to do it on a specific vehicle.
I was stuck in my thinking along the lines of multiple sized airbags available for different suspensions so there would be so many variables, but what you say makes perfect sense if you have your knowns up front it would be a very cheap addition to an air bag system to make an accurate "Scale" on your chassis with pressure gauges.
Might I inquire of you on your truck, did you have independent air bag controllers for side to side on height control or did you have one valve per axle or one valve for all four bags? (I am assuming you had tandem drive axles.)
If you had a divided system did you have to have more than one air gauge?

 

[Bob86ZZ4]

Will they let you try hooking up your trailer and pulling it down the road a bit? Like to the nearest scale? If not then next best thing would be to figure out how much tongue weight your trailer has. You can do that by weighing your rear axle with the trailer hooked up, and not hooked up. Then go weigh the Truck Conversion rear axle. With a full water tank would be best, otherwise do the math and add that to the rear axle weight. Now check the rating on that single rear axle. Is it going to be at, or near, the max when your trailer is hooked up to it? If yes, there's your answer. My rig is 26' living quarters on a single rear axle. My rear axle scaled at 17k lbs. with half a water tank I think. My axle is rated at 22,700 lbs. If your 21k lb. trailer has 10% tongue weight, and that 28' rig is similar in weight and axle rating to mine, I think you'd be fine according to the ratings. Buy don't take my word for it.

 

[Bottomland4x4]

Not really possible to hook up and try it. If I go with the motorhome style I will have to fabricate a hitch to go from bumper pull to attach to a gooseneck. I may end up going to a 17 foot toter, single axle. Both 22 foot tandem axle toters that I was looking at sold this weekend. That's about my luck, they have been for sale for 2 months, and end up selling the day before I go to look at and put a deposit on. The search continues! Lol!

 

[Bob86ZZ4]

Sorry about missing out on those ones. I've missed out on tons of vehicles that I thought I would buy. Turns out every time that happened actually worked out for the best for me.

I didn't realize you're pulling a gooseneck trailer. That solves that for me. Get a Toterhome. I know there are dolly's you can use to bumper pull a gooseneck. But I think you'd be better off keeping the same configuration you've got now, just a bigger living quarters is what you need.

 

[Bottomland4x4]

Here isa pic of my buddies setup, he has a 30 foot Coronado renegade and he pulls his 40 foot gooseneck on this hitch. I know the he is probably over length, but he said it pulls really good. He does have tandem rear axles.

 

[Bob86ZZ4]

Wow, I've never seen something like that. Looks pretty cool. Looks like the trailer would be pretty close to the box though. No tight turns.

 

[Bottomland4x4]

It's not too close, he can only pull open trailer goosenecks of course, but he can turn as sharp as a bumper pull. The only danger i see is if he were to turn up a steep hill and catch the top of the trailer against the back of the toter. He said it pulls as good as his bumper pull.

 

[neetchracer]

My 15' gooseneck toter has a single axle. The rear weighed 15000# with an empty, standard height, 38' enclosed trailer. I since nearly completed(well....over halfway) my stacker trailer build and am excited to get this stuff on the scales again. The big problem with GN toters is the front axle weight. I'm moving my hitch back about 20" to try and lighten the front some.