Community Forums

Myotis · 01-16-2008, 01:50 PM

I have a 2005 Durango 5th-wheel made by KZ. The model number is 285RD and the chassis number is 4EZFS28205S063437. I am towing this 5th-wheel with a 2000 Ford F250 SD. When I bought the 5th-wheel the RV dealer had to change the set-up on the RV to make sure there was enough clearance between the 5th-wheel gooseneck an the truck bed rails. Modifications included installing 16" wheels instead of the standard 15", flipping the axle and setting the axle adjustment to the highest point. The modifications resulted in a 5" clearance, less than the recommended 6 – 8", but in three years of towing I had no problems. However I am looking at replacing my truck and noticed, and measured that the new truck models, especially GM trucks, are sitting about three inches higher than my current truck. In addition the bed rail is one inch higher than the current truck. This means that the RV would have to be raised to get sufficient clearance and to make sure the RV is not towed "nose-up"

QUESTION: is there a way to modify the frame, axle or springs on the 5th-wheel raise the RV 3 inches without compromising the towing safety? If yes, could a regular RV dealer make those modifications or would I have to find a specialist with experience in modifying the frame and axle mount? Any recommendations which companies (Oregon) could do such a job?

Any sugestions are highly appreciated.

Myotis · 01-16-2008, 01:50 PM

I have a 2005 Durango 5th-wheel made by KZ. The model number is 285RD and the chassis number is 4EZFS28205S063437. I am towing this 5th-wheel with a 2000 Ford F250 SD. When I bought the 5th-wheel the RV dealer had to change the set-up on the RV to make sure there was enough clearance between the 5th-wheel gooseneck an the truck bed rails. Modifications included installing 16" wheels instead of the standard 15", flipping the axle and setting the axle adjustment to the highest point. The modifications resulted in a 5" clearance, less than the recommended 6 – 8", but in three years of towing I had no problems. However I am looking at replacing my truck and noticed, and measured that the new truck models, especially GM trucks, are sitting about three inches higher than my current truck. In addition the bed rail is one inch higher than the current truck. This means that the RV would have to be raised to get sufficient clearance and to make sure the RV is not towed "nose-up"

QUESTION: is there a way to modify the frame, axle or springs on the 5th-wheel raise the RV 3 inches without compromising the towing safety? If yes, could a regular RV dealer make those modifications or would I have to find a specialist with experience in modifying the frame and axle mount? Any recommendations which companies (Oregon) could do such a job?

Any sugestions are highly appreciated.

450Donn · 01-16-2008, 02:18 PM

Ok, you have double posted. This is not allowed, and the moderator will probably close one of them.

450Donn · 01-16-2008, 02:25 PM

Kind of had the same problem when I got rid of the Chevy 4X4. All of the new trucks were way higher, and I was unwilling to jack my trailer farther off the ground than it already was. So, my solution was a 4X2 instead. Since then, I actually dropped my trailer back to it's stock height. Amazing how suck a little thing makes such a big difference. If you are unwilling to compromise, then one solution would be new spring packs for the trailer. A place like Benz Springs could make you up what ever you wanted. But again do you really want to drive the trailer another three inches higher up in the air?

Myotis · 01-16-2008, 04:04 PM

Sorry, didn't know about this rule, just wanted to make sure that I get an answer, did not expect to get a "lecture" though.

Moderator, please remove my positing on this forum and leave it on the main 5th-wheel forum.

Thanks,
Myotis

Myotis · 01-16-2008, 04:13 PM

Thanks Don,

did not see your second response. Yes, I am wondering if I should raise the 5ver although it seems to really ride low. I got comments on RV parks how low this Durango sits. I am not sure what's going on here, the RV dealer told me that the 5ver was "designed to be towed by a 1/2 ton truck. Yeah right, with a pin weight empty of 1400 lbs and the main storage being in front of the 5ver axle. I weighed my truck and even the 3/4 ton is maxed out with the 5th-wheel hooked up. An engineering friend suggested to build up a "sub frame" but I am not sure if this would work. My friend and I are both retired electrical engineers and have no experience in RV chassis design :-). That's why I am posting my question.

Again I apologize for the double posting and the little bit "pouting" first response I sent.

I need all the help I can get.

Best Regards,
Myotis

450Donn · 01-17-2008, 08:51 AM

Sorry, I was not trying to lecture you, just advise you about double posting.
Just curious, with the fiver sitting level, what is the height from the ground to the bottom of the overhang? And from ground to the pin? I do know that with my Dodge before the pin weight hits the truck the rear end measures to only have a couple of inches free board. But when all the pin weight is on the truck the truck is level and I have about 7 inches. Are you looking at a 4X4 or 4X2? There is a difference in ride height. Like I said, that and the fact that I rarely used the 4X4 on my TV so why spend all that extra money and loose towing capacity to boot. I think I would look into new springs before I added a sub frame. Adding a sub frame would require a lot of welding and fabrication, and in the process if you have any left void the warranty. Better still might be to replace the spring hangers with longer ones thereby raising the trailer. This would still require welding and if done wrong could cause your trailer to track wrong. Since you are local to me, if you need any other suggestions, just send me a private email.
Don

rrraider · 01-19-2008, 01:40 PM

We had a Cameo TT that really needed some extra clearance for the places we go; back end and steps always taking abuse. What I did that worked really nicely was to remove the old spring hangers and add 2"X3"X1/4" tubing to the frame, install new hangers and the trailer was then 3" higher of course. I also went back with a heavier axle and springs and 'E' tires for more capacity. An extra benefit is that the tubing upgrades the capacity of the frame if you cover 30% or more of the frame length.
Randy

charliez · 01-29-2008, 03:44 AM

You can't just walk up to a truck and measure. You have to add in the distance the truck is going to sink when the pin is set down. Trucks these days have progressive springs so they are soft when riding around town but stiffen up as they compress. To know for sure, you will need to set the pin down on it. I doubt a salesmen would let you do that. It wouldn't hurt to ask though.

Half Dimes · 02-03-2008, 05:28 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by charliez:
You can't just walk up to a truck and measure. You have to add in the distance the truck is going to sink when the pin is set down. Trucks these days have progressive springs so they are soft when riding around town but stiffen up as they compress. To know for sure, you will need to set the pin down on it. I doubt a salesmen would let you do that. It wouldn't hurt to ask though. </div></BLOCKQUOTE>
We went through this when we bought our last truck. I knew my approximate pin weight so I had our salesman round up enough of his rotund counterparts to equal the pin weight and we all piled into the bed of the truck as close to the axle as we could while my wife stood at the side with a tape measure checking the difference. Worked very well. Only wish I had taken a picture.

Myotis · 02-03-2008, 05:53 PM

Thanks, that is an interesting suggestion, I wished you had takena pciture as I am trying to envision 8 sales guys in the truck bed to "simulate" 1600 - 1800 lbs pin weight

But it is a good idea,

Thanks,

Tugboat · 02-03-2008, 07:53 PM

We are looking at new trailer's right now. I called PullRite about clearance for my 2005 F150 Super-crew 4X2 it has high bed rails. They told me how to measure the truck. And then how to measure the trailer to make sure there is a minim of 6 inches of clearance. If it won't clear they told me to talk to the dealer about a installing a different PinBox.

Also look at this option it could also work.
RV5 King-Pin exten

RustyJC · 02-04-2008, 04:09 AM

The kingpin extension you've linked to functions just like a (further) extended pinbox. As such, it introduces a significant additional moment (torque) to the 5th wheel's pinbox-to-frame junction. Your 5th wheel may or may not be able to accomodate this added force - I'd check with the manufacturer before using it. I've owned 5th wheels where only a straight pin box was supplied, and no extended pin box was approved for use.

Rusty