Axles: Leaf spring vs. Torsion

[mikeschn]

Thanks, I feel better now!!!

Mike...

[Cary Winch]

Here is my two cents on the torsion axles. There are a couple of brands out there that have splined shafts and forged trailing arms. We use one of these brands ourselves. The splines allow you to adjust the ride height by remounting the arm. This really works out well.

Also on the splined versions it is possible to pull the torsion cartridge out of the axle tube if need be. There is a couple of spot welds that need to be cut.

One nice thing that most people overlook on the torsions are that they track straight with no side to side motion. This allows you to get the tire closer to the fender and body with no rubbing. The street rod guys love that part.

Another neat thing about some of the torsion axles is that the dealers usually just carry the parts. You tell them the dimensions and they cut the axle tube, weld on the bracket and install the cartridges.

I have found the price difference to be less than $75 for a torsion versus leaf spring.

Cary

[mexican tear]

You can not replace the internals of a modern tortion axle. They are made by putting a rod in rubber that is squished, frozen and then inserted in the square tubing. It is not a torsion bar like the VW.

If the tortion axle is an axle it has mounting pads that can be welded to the frame and then cut off and moved if necessary. I have moved mine once and suspect that I will have to move it one more time to get the toung weight correct. I plan on waiting until the total TD is completed.

I have a 30 ft travel trailer that has torsion axles on it and I think they use them on the Airstreams.

kai

[asianflava]

He welded the torsion axle to the frame.
Mike...

Isn't this an advantage of the torsion axle? It can be a stressed part of the frame thereby decreasing the weight and complexity of the frame.

[TRAIL-OF-TEARS]

Here's a crazy question. If I get the 2000lb tortion axels but my tear only weighs ~ 1600lbs (loaded) will that cause the traiiler to bounce? or is the 2000lb just the limit. I would think they would use softer rubber for a lighter weight axle. thanks

[Cary Winch]

Kai,

With many of the torsion axles out there (like the Reliable you used) this is true that the torsion parts are not removable. The torsion components are installed right into the axle tube. Some brands though like Flexiride have the torsion rubbers mounted in a cartridge. This cartridge is then removable. So you would end up replacing the whole torsion component stubs and all but leaving the axle tube in the trailer.

Asianflava,

You are right that with the torsion you can and should use the axle as a structural component of the frame. You can do this welded as suggested or bolt the axle in. This too would give you the strength you are looking for.

Cary

[Cary Winch]

Jakob,

Your questions is not crazy at all. The 2,000lb number is the total loaded limit of the trailer weight. The closer you get to that number the less it will bounce. But, you don't want to get too close and go over. We use the 2,000lb units and most of our trailers weigh in about 900lb-1,100lb empty. This seems to be the sweet spot where is starts riding smooth. We make some base models that are closer to 700-750lb and they ride a bit bouncy. A loaded 1,500lb-1,600lb tear with a 2,000lb axle should ride real nice.

Cary

[TRAIL-OF-TEARS]

Jakob,

Your questions is not crazy at all. The 2,000lb number is the total loaded limit of the trailer weight. The closer you get to that number the less it will bounce. But, you don't want to get too close and go over. We use the 2,000lb units and most of our trailers weigh in about 900lb-1,100lb empty. This seems to be the sweet spot where is starts riding smooth. We make some base models that are closer to 700-750lb and they ride a bit bouncy. A loaded 1,500lb-1,600lb tear with a 2,000lb axle should ride real nice.

Cary

Thanks, Cary
That is what I suspected. so we are looking to get the weight at about 80%.

[R Keller]

Jakob:

I can only speak regarding the Dexter axles (my previous statements in this thread should have stated that, since obviously some other axle brands have different features).

Dexters don't have splined shafts. You specify the "start" angle. And that's that. You also specify the Gross Axle Weight (GAW = total weight of trailer minus the tongue weight) and they customize the amount of rubber in the axle to provide the appropriate ride characteristics. The axle itself has a total weight rating above that. For example their #9 Torflex axle can be specified for a GAW of anywhere from 1,000 to 2,200 lbs. All of the components are the same, it's just the amount of rubber that they insert that varies...

Rik

[angib]

This torsion.vs.leaf is also a cultural thing - no-one in Yurp uses leaf anymore, whereas in Merka you seem about evenly split.

You might want to see the Al-Ko trailer site. Al-Ko are the biggest supplier of TT chassis in Yurp. You have 3 options:
(1) just look at the pictures
(2) look through a translator like Babelfish
(3) if you can read German, you can explain to everyone else what it says.
This is getting to be real clever stuff with the torsion axis offset both horizontally and vertically.
Andrew

[mikeschn]

Well, here on T&TTT we seem to be more in favor of Torsion than Leaf... so does that make us more sophisticated like those folks in Yurp? Heaven forbid we be like those Merkans in California... LOL (No offense folks, really)

Al Kon habe ich nicht verstanden... kannst du das fur mich ubersetzen?

Bitte...

Mike...

[BoilermakerFan]

The German words I know can't be posted here since this is a family site!

So Cary, want to save us the trouble and post which axle manufacturers have the splined units? Is Flexride one of the splined units or just a cartridge type?

Brian

[Cary Winch]

Brian,

Oh, I guess I was vague on that. The Flexiride are a splined cartridge style. They use a forged trailing arm that is really nice. I believe that the Henschen axles are splined also. But I don't know if they are cartridges or not. Anybody know?


Cary

[Chip]

springs vs tortion,,,its my opinion that it will depend on the kind of service you are looking for and how hard you are gonna abuse ya trailer getting to the outback,,,for me a tortion axle is fine cause I am on paved and or improved dirt roads,,now id ya gonna take the trailer out rock hopping or canyon jumping,,you might think more on the lines of a extra strong axle with shocks and springs designed to take the stress of off-roading,,tortion is typically gonna give ya less ground clearance where springs/axles can give ya more,,

2 more cents worth

chip

[angib]

... so does that make us more sophisticated like those folks in Yurp?

In this case, Yurpeens aren't serfisticated, just cheap. Torsion axles are more cost- and space-efficient - do any OEMs in the US still use leaf springs?

Al Kon habe ich nicht verstanden... kannst du das fur mich ubersetzen?

Ner, not me, mate - I don't do Chorman. But I can give you a couple of cracking examples from that Al-Ko site:
Sechskantgummifederung = hexagonal rubber suspension
Wankwinkelverbesserung = lean angle reduction
Der flippenfloppenmuckensprederung = windshield wipers... no, wait, I just made that one up.

Andrew