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Discussion Starter #1
My Jayco X213 sits pretty low to the ground, which is a real annoyance because I am often dragging it down crappy dirt forest trails. Lifting the trailer is a large task as it has torsion arm axles which are welded to mounting plates on each side that bolt to the frame. I would have to make some kind of drop plate.

It currently has ST185/80R13's which is a 24.4" tire. They are due to be replaced and I am thinking I might try to move to an ST205/75R14 or ST215/75R14 which are 26.3-26.8". This would gain me 2+" in OD and 1" of clearance.

Is there any negatives I should be considering? The distance between the tires currently is 4", so that would be down to about 2" with the ST205.
 

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I would think clearance is the only thing to worry about. If a taller tire has the needed room, you get the benefit of ground clearance and a bit of rpm reduction.

Torsion. So no flipping the axles from over the leafs to under the leafs.

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Discussion Starter #3
I would think clearance is the only thing to worry about. If a taller tire has the needed room, you get the benefit of ground clearance and a bit of rpm reduction.

Torsion. So no flipping the axles from over the leafs to under the leafs.

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Yeah, I actually measured the length of the trailing arms and distance between the axles and modeled in CAD :ROFLMAO:

The stock tires could contact in an extreme scenario, where the front tire is near normal ride height and the rear is drooped almost vertical.
163950


With the ST215's its a lot less extreme:
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I did also model some plates to lift the trailer about 6 months ago but I am worried about hacking the thing apart and potentially ruining resale value:

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163953
 

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Man, you've been mulling it over seriously.



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Discussion Starter #5
I just went out and took at tire off and played with the trailing arms. They really do not move very far at all. Tire contact should be a none issue, even if I got something even bigger than the ST215/75R14.

Free Hanging:



Jacked up from the hub, all weight from that side of the trailer on the one axle:

 

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Good job. If that is total sag, you can definitely change your geometry lab-work. :)

Can you take advantage of the available clearance with the current wheel size?

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Discussion Starter #7
Good job. If that is total sag, you can definitely change your geometry lab-work. :)

Can you take advantage of the available clearance with the current wheel size?

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No I am going to have to move up to the 14" or 15" wheel. I can only go down in size on the 13" wheel.
 

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Here is the lift my Rockwood has for the torsion suspension. This is to clear the slide so the entire trailer floor is flat.



Here is the tires clearance between each other. These are 205/75/14 tires.



Here is how much the torsion bar is when full weight on all 4 wheels on level ground.



When I had my old 2003 Prowler with the same size 13" tires you have, I thought about upping to 14", but I would not have had enough room between the tires, or the top of the wheel well.. I too wanted to lift it a couple of inches. They do have 'kits' to lift the torsion axles, but required more work and tools than I have.

Here is a pic of my old Prowler with the 13" tires. It does look like there is a lot of space between them, but I could not even fit one of those scissor tire lock things between them... I can use one of those with my new trailer however..



Good luck! Mitch
 

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Discussion Starter #9
Here is the lift my Rockwood has for the torsion suspension. This is to clear the slide so the entire trailer floor is flat.



Here is the tires clearance between each other. These are 205/75/14 tires.



Here is how much the torsion bar is when full weight on all 4 wheels on level ground.



When I had my old 2003 Prowler with the same size 13" tires you have, I thought about upping to 14", but I would not have had enough room between the tires, or the top of the wheel well.. I too wanted to lift it a couple of inches. They do have 'kits' to lift the torsion axles, but required more work and tools than I have.

Here is a pic of my old Prowler with the 13" tires. It does look like there is a lot of space between them, but I could not even fit one of those scissor tire lock things between them... I can use one of those with my new trailer however..



Good luck! Mitch
Thanks for the pics!

Yes the tires are only 4” apart currently so i expect they will be 2” when all is said and done. I don’t currently have the scissor stops but have heard they are awesome.

My trailing arms look similar to yours in the resting position, just slightly down. However, mine are mounted much different. My frame is a C-Channel and then the axles are mounted to it on some plates with 4 bolts per side that run through the frame horizontally. The axle tubes actually pass through the frame and the frame is notched to accommodate.

IMG_7252.JPG


So those tubular lifts from dexter dont work on mine unless I also makes a subframe to mount them too. I can “weld” but not brave enough to test my welding on a 5500 lb trailer frame
 

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I found a couple of other pics of my old Prowler torsion setup.




The torsion bar plates were bolted to those U shaped bars welded to the I frame of the trailer. So, even this had a slight lift to it, but the inner fender wells were inside the trailer.

The "kit" I found was meant to add another U shaped bar to bolt/weld to the original bolt holes and added about another 2" or so lift.

On my new trailer, I like the fact that they have welded in an additional cross member between the lift piece just above the axle. These are #3500 axles as well.. Even the old Prowler had #3500 axles..

Mitch
 

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As you've already found out the movement in the torsion style suspension is minimal. On my Jayco I went from the 13" to 205/70 or 75-14 and there is still a lot of room between them. I also did a 3" lift similar to the one you designed. The extra 4" was needed because well, these are just too low. My gray/black water outlet was only about 3" off the ground. Now I don't worry about dragging them even if I have to drive straight off a curb or when I go off road to hunting camp - from where I just returned.
 

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Discussion Starter #12
I ordered the ST205/75R14 instead of the 215/75R14, mostly because I could get those in a D range rated for 81 mph in the tire I wanted and because I didn't wanna go wider than I needed. Also ordered a new set of aluminum wheels to go along with them.

While I was looking around the Jayco forum I stumbled across this:


The guy had already designed a installed these lift plates on his trailer and a few others have tried them as well. He was kind enough to put up the DXF file for the plates so I decided to try these instead of using my own plates that have not been proven. The guy who built the bigger turbo for my Liberty has a CNC plasma cutter so he cut these out of 3/8" steel the other day. These will give me 3" of lift and, with the bigger tires, I should be up a total of 4".
 

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Those extreme torsion movements will only be an issue if you drive the trailer up a curb or something that is a sudden drop off. Not something you typically do with a trailer in tow. On any gradual incline or decline the other tire will move with the front tire. I think you're fine if the pre-clearance before going up is ~5" or more. On the Rockwoods like Mitch and I have, the tires are already pretty close to begin with.
 

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While I was looking around the Jayco forum I stumbled across this:

Not too long after I rigged up my lift he came out with that design and I sure wish he would have done it sooner. It is really nice and works well.
 

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Discussion Starter #15
New tires and wheels. I ordered 5x of each but somehow Walmart screwed up and never shipped one of the tires. Customer service just reordered it today and its supposed to be here Tuesday.

IMG_7453.jpg


The lift plates that my turbo guy cut are on there way as well. Hoping they will also show up early in the week since we wanna camp next weekend.
 

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Discussion Starter #16
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Got em swapped. I would be more excited but I had the trailer hooked up to my jeep and when I went to go take it for a test drive to make sure the tires were good, the engine started knocking and **** the bed. Pretty sure it dropped one of the exhaust valves into the cylinder.
 

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Discussion Starter #17
Brought the trailer down to the Goblin Valley State park area in southern Utah. It ran great with the new tires. Very stable and just cruised along very drama free.

IMG_7568.jpg


No one was there. I think the closest camper I saw was about 5 miles away. It was insane.
 
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