Flipping the Axle

[Art Davis]

I know that there have been several discussions here about "high-rise" axles. I recently stumbled across the idea of "flipping the axle," meaning changing the position of the axle from above the leaf springs to below them. I tried doing a search here, but (probably because of my ineptness) I didn't come up with anything specific. Found references to axles and to the high-rise axle on the Casita.

Does anyone know anything about this----or about a thread here where this issue is discussed?

Thanks.

Art

P.S. Here is a link to a site that discusses it. What do you think?
Flipping the Axle

[Victor Benz]

I have done this with every trailer I have owned. The main reason is to gain sufficient ground clearance to protect the waterworks during bush trips. The penalty is one of gas mileage while towing. The higher profile of the trailer does grab extra air. Points to ponder are:

NEVER, NEVER re-use u-bolts and nuts, especially nylok nuts
Mark the alignment first
Consider having it done by a dealer
Check the towing alignment immediately afterwards, and if the trailer is not tracking properly, take it to a specialist.

I had my first trailer (dual axle stickie) done ina spring and axle shop that ensured alignment.

I did another one myself.

The Fiber Stream was done in an RV shop that told me "no guarantees on alignment".

I had no problems with any of these methods.

Victor

[BobB]

Here is a thread where there is some discussion of "flipping".

http://www.fiberglassrv.com/board/in...howtopic=24562

There is another where someone switched from a drop axle to a straight axle in order to raise the trailer.

[Brian B-P]

The proper terminology is a conversion from a "spring-under" or "underslung" spring configuration to a "spring-over", or "overslung" spring configuration... searching for those terms may be more productive.

Many trailers with Dexter axles come with a Dexter publication which may cover these configurations; certainly, the Dexter website does.

In addition to the issues with Victor already identified, and the obvious need to climb higher to get in the door, a higher trailer with the same tires, springs, etc will certainly be less stable and have inferior handling response. It may be not enough to be a problem, and may not even be noticeable to the owner, but it will happen; there's a reason that cars which handle well are lower.

The Casita option is a specific configuration of a rubber-sprung torsion axle, such as Dexter's Torflex; the spring-under/spring-over configuration choice applies only to leaf-spring beam axles, such as in most Bigfoot trailers, the large (1700 series) Bolers like mine, and very few other moulded fiberglass trailers.

[Rob S.]

One last tidbit to check is if you have a straight axle or a drop axle. I wanted to raise my Boler 1700 by switching from a spring under to spring over but because my old running gear utilized a 4" drop axle the only thing I was going to raise was the trailer and frame. My actual axle was still only 5" from the ground which was no good for some of the logging roads we like to frequent. I switched to a straight axle and gained 4" of clearance on the entire trailer including the axle. As many will attest even within a particular year running gear differs depending on where your rig was manufactured. Sometimes it appears as though they used what ever brand and type of running gear they were affordably able to get their hands on so there doesn't seem to be a clear standard.

Rob

[V'sGlassSleeper]

I posted the reasons for and results of our choosing to have our drop axle changed to a straight axle here:

http://www.fiberglassrv.com/board/index.ph...mp;hl=clearance


If you are looking to gain clearance under your entire rig, I highly recommend going the route we did, because it genuinely gives you 4" more under the axle as well as the trailer body.

Good luck and please post your results...it adds to all the helpful data available!

Val

[Brian B-P]

P.S. Here is a link to a site that discusses it. What do you think?
Flipping the Axle

I suppose that's a decent description. If the bushings are in good shape, it would be a simpler procedure, but still essentially the same steps.

It assumes that the new spring perch is welded on, which is the preferred method (although converting from drop to straight axle like Rob is even better), but entirely bolt-on conversion kits are available from Dexter. That could make do-it-yourself viable... and would be quite reversible.

[Frederick L. Simson]

I have done this with every trailer I have owned. The main reason is to gain sufficient ground clearance to protect the waterworks during bush trips. The penalty is one of gas mileage while towing. The higher profile of the trailer does grab extra air.

Fiber Stream used straight axles. A previous owner changed my Fiber Stream from the spring under configuration to the spring over. At first, I was concerned about total height, (getting into my shop through a 9' tall door) and wind resistance/decreased fuel economy. Also, the 18" threshold height is difficult on my old knees with just a Rubbermaid Step Stool and no pull out steps.

But the original stance of the trailer would have been too low for the Weight Distribution Hitch spring arms.

[Pete Dumbleton]

There are some really good tips in here, but one bottom line is that for torsion axles, the only way is to replace the axle because it can't be disassembled (one obscure brand allows changing the down-angle).

As noted above, a spring-over won't change the distance between the axle beam and the ground because that is a direct function of the wheel/tire radius, however the new clearance at the fender may allow an upsize of wheel/tire.

If doing a spring-over on a leaf spring axle, it's important to limit the new travel of the springs to what the old travel was or you risk early failure and breakage of the springs (experience speaking here); Dexter has a note to this effect in their Under/Over-Slung parts kits.

One unsung advantage of raising the trailer is that it is likely to reduce the underside's air-dam effect, which in my experience will more than offset the increased frontal area up top. It will also raise the trailer's center of gravity with resultant lesser handling quality.