I need shocks!! (1 Viewer)

[Solace in Solitude]

I have a 2019 R-Pod 20’ travel trailer that my 2002 Tundra pulls extremely well, using only a friction sway bar.

It’s a Hood River Edition, built for off highway use, and is built on a Dexter Torsion Axle... which is supposed to handle/mitigate bounce.

It doesn’t... I’d like to add shocks, but have no idea what to consider in planning this addition.

Can someone(s) please offer insight into what I need to consider... especially regarding where a to-be-fabbed shock tower and to-be-fabbed shock bracket should be installed, in relation to the single axle?

TIA

 

[greentruck]

Found the website and it looks like there are a variety of models.
Torsion Axles | Dexter Axle Co

If you know which axle you have under yours, it could be helpful in suggesting solutions.

The first thing I'm curious about would be what's your usual all up weight vs the rated capacity of these axles? I have no experience with them, but some experience with torsion bar suspensions (I used to drive Isuzu before I got back into Land Cruisers). There is some limited height adjustment available but the weight carrying capacity is pretty fixed. If you need more guts, you need a stouter torsion bar. Not sure that shocks will help you here.

There's also the problem of mounting such an arrangement. That torsion arm the spindle is mounted on seems to have no good spot to mount to. It also looks cast and that may present issues with welding.

You may want to do some more research here before diving into adding shocks. It may be cheaper to upgrade the axle instead and give better long term results.

Finally, have you talked with Dexter tech support on this? I'd bet they could offer some insights.

 

[ntsqd]

Only pic that I have of the RS9000's on our TrailBlazer trailer with the rubber torsion axle:

They're simply roll cage mount tabs welded onto the end of the trailing arms.

The trailing arms are steel and not iron. I did not do the work, but it appears that the guy who did had no trouble with welding the tabs on. Since they were welded on this trailer has seen Mexico's Copper Canyon, many, many roads in Baja, and made it clear up to Sand Lake OR.

I'd be interested in what Dexter has to say about adding shocks. My understanding of their stance on the topic from many years ago was that they are not needed. I say that they are needed if off pavement and rough roads use is going to happen.

 

[cruiserpilot]

Only pic that I have of the RS9000's on our TrailBlazer trailer with the rubber torsion axle:

They're simply roll cage mount tabs welded onto the end of the trailing arms.

The trailing arms are steel and not iron. I did not do the work, but it appears that the guy who did had no trouble with welding the tabs on. Since they were welded on this trailer has seen Mexico's Copper Canyon, many, many roads in Baja, and made it clear up to Sand Lake OR.

I'd be interested in what Dexter has to say about adding shocks. My understanding of their stance on the topic from many years ago was that they are not needed. I say that they are needed if off pavement and rough roads use is going to happen.

Thanks for this. First decent method I’ve seen on the torsion axles. Don’t suppose you have a pic of the upper mount location? Certainly worth it off road I think.

 

[Solace in Solitude]

Thanks guys! Good info!

I just returned from So-Colorado today and need to rest up for a couple of days.

The axle is a Dexter Torflex 3500lb... I’ll speak with Dexter.

I haven’t weighed the trailer “loaded”... it’s 2649 “dry”
Cargo weight is 1136lbs

Total 3785lbs

And, with propane, battery, clothes, food, tools, utensils and bedding”, I’d guess about 3449 “wet”.

The tanks are:

Fresh: 36gals: 36*8=288lbs
Grey: 30 gals: 30*8=240lbs
Black: 30 gals: 30^8=240lbs
Total FULL= 768lbs

3449lbs (wet) + 768 = 4217lbs total wet weight.

But:

I always drive with:

fresh at 1/3 full, or 12gals*8=96lbs

grey nearly empty... say 2gals*8=16lbs

Black nearly empty... say 2gals*8=16lbs

3449lbs + 114lbs = 3563 <— less than the 3785lbs allowed.

I just found an old 2014 post on a Forest River forum that said, “Main thing is to try to get the shock mounted as close to 90 degrees to the torsion arm when it is in the loaded position.”... from post #17 —> Shocks - Page 2 - Forest River Forums

... and here are pictures of how the shocks were mounted —> Forest River Forums - 09grizzly1's Album: 09grizzly1's Shock Install. <— (Edit: @cruiserpilot)

Like I said, I need to sleep on this... but, the two links above may have already answered my questions... I think I was overthinking this.

 

[greentruck]

Danny,
I took a read in Dexter's installation instructions and came up with a couple of things to check. Both of these are on page 8 from this link:
Dexter Axle Applications Manual

"Torflex® axle ride performance is at its best when the torsion arm is at or nearest to horizontal when the vehicle is at its rated load."

It definitely sounds like you're certainly at the rated load, so this being any other way when loaded would be cause for further investigation. Then there's this:

"Axle capacity will be reduced by at least 50% when used without a suspension system (axles or stubs attached directly to vehicle frame). This is NOT a recommended configuration as it transfers load directly to the frame rails and is a very harsh ride."

I assume this issue is not a factor. Might be worth a review.

That said, I'd be uncomfortable riding so close to the rated capacity. Dexter indicates that you should be close, because that affects ride height/ride quality, but I'd think you'd want 500 lbs under vs 500 lbs over. But they're the ones to ask when you need to get real specific because they likely have the exact info needed to say what the significance of your problems may be.

 

[Solace in Solitude]

Danny,
I took a read in Dexter's installation instructions and came up with a couple of things to check. Both of these are on page 8 from this link:
Dexter Axle Applications Manual

"Torflex® axle ride performance is at its best when the torsion arm is at or nearest to horizontal when the vehicle is at its rated load."

It definitely sounds like you're certainly at the rated load, so this being any other way when loaded would be cause for further investigation. Then there's this:

"Axle capacity will be reduced by at least 50% when used without a suspension system (axles or stubs attached directly to vehicle frame). This is NOT a recommended configuration as it transfers load directly to the frame rails and is a very harsh ride."

I assume this issue is not a factor. Might be worth a review.

That said, I'd be uncomfortable riding so close to the rated capacity. Dexter indicates that you should be close, because that affects ride height/ride quality, but I'd think you'd want 500 lbs under vs 500 lbs over. But they're the ones to ask when you need to get real specific because they likely have the exact info needed to say what the significance of your problems may be.

Thank you!!

I’ll contact Dexter for specifics... I’m sure I’ll not be the first to ask them.

 

[ntsqd]

I disagree with that shock mounting advice. In a perfect world it should be slightly less than straight up and down, and it should move to exactly straight up and down as the suspension compresses.

Better shot of the lower mount showing that I need to pay the trailer some attention:

Upper mount, looks like time for some new shocks!

I have to think this is not in reference to torflex axles and is instead in reference to 'normal' axles:
"Axle capacity will be reduced by at least 50% when used without a suspension system (axles or stubs attached directly to vehicle frame). This is NOT a recommended configuration as it transfers load directly to the frame rails and is a very harsh ride."

 

[greentruck]

I disagree with that shock mounting advice. In a perfect world it should be slightly less than straight up and down, and it should move to exactly straight up and down as the suspension compresses.
SNIP

I have to think this is not in reference to torflex axles and is instead in reference to 'normal' axles:
"Axle capacity will be reduced by at least 50% when used without a suspension system (axles or stubs attached directly to vehicle frame). This is NOT a recommended configuration as it transfers load directly to the frame rails and is a very harsh ride."

I tend to agree, despite the expertise that one would think would go into that application guide. You'd want shocks to compress to that point, but not be there to start with. Otherwise, with every compression you'd go from ideal to less than ideal, depending on how hard the jounce is. Thus my comment that you'd be better off 500 lbs under an axle's rated capacity than 500 lbs over with torsion bars/Torflex as the suspension.

On that second paragraph, I was thinking that the Torflex system was also available as two discrete units in addition to the complete axle, but perhaps I'm thinking of something else? But you may be right that it's boilerplate language that should have been edited out.

 

[ntsqd]

Just had a look at that FR forum's pics. A flat plate like that is the least desirable shock mount design. Unless you make it from 3/4" thick plate it is too flexible. I see that there's not a lot of room to work with there, but the upper mount needs to be more robust than that or it will fail off-road.

 

[sailor]

I don't know about mounting shocks to the RPod but I suspect that taking it on a rough road for any length of time will reduce the structure to a number of piles of sawdust.... Budget trailer.