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John Bacon

Under to Overslung Axle

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I'm planning to order a new axle for my trailer.

My current axle is under slung (axle on top of spring).  I am contemplating switching to over slung to gain a couple more inches of clearance.

Would there be any negative effects to making the switch?

 

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Yow will likely need a different ball mount; so that the trailer frame rails will be level when hooked to the tow vehicle. The optimum tongue height is 17 - 19" (Level trailer) measured from the ground to the inside top of the ball coupler. An axle flip will give you more frame clearance; but not axle clearance. Axle clearance is determined by wheel & tire size. Like what was said above, you will loose some stability. Going down a smooth hwy, you'll likely not feel any difference in the handling. There's only vertical down pressure on the springs. It's when one wheel goes over a bump or dip in the road; is where you'll feel it. Because of the horizontal side load on the spring. It will force the spring to twist; when the load is gone the spring will return to its normal position causing the trailer to sway. Rule of thumb is to have the center of the axle to be as close as possible to the center of the spring's mounting eyelets. The diagram explains this better.

Springs.png.60ec329d337b9ff2a38b717d30745cda.png

Seems like a lot of extra effort, just to gain 3-4" of frame clearance and possibly loose some stability?

Dan.

 

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Thanks, I'm replacing the axle due to the bearing issues anyway.  So, there really isn't much effort involved.  But thanks for the technical input.  I am towing with a fairly low vehicle; so it sounds like I would be better off stay with an under slung axle.

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I recall when I went from a van to a pickup I needed height to level the trailer, there was about three sets of holes for the bolts at the ends of the springs to make an adjustment if you want a bit more clearance. It was an Easy Loader trailer.

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5 hours ago, DanD said:

There's only vertical down pressure on the springs. It's when one wheel goes over a bump or dip in the road; is where you'll feel it. Because of the horizontal side load on the spring. It will force the spring to twist; when the load is gone the spring will return to its normal position causing the trailer to sway. Rule of thumb is to have the center of the axle to be as close as possible to the center of the spring's mounting eyelets. The diagram explains this better.

Springs.png.60ec329d337b9ff2a38b717d30745cda.png

Seems like a lot of extra effort, just to gain 3-4" of frame clearance and possibly loose some stability?

Dan.

 

Nice info to be aware of.   Damm thumbs have more rules than...

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Be aware not all new axles come with the spring seats welded in place...you will have to measure them out the  same distance as the old ones and weld them in place yourself.?...just an FYI

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16 hours ago, Whitespinnerbait said:

Be aware not all new axles come with the spring seats welded in place...you will have to measure them out the  same distance as the old ones and weld them in place yourself.?...just an FYI

I ran into this problem with my new axle. Went to a trailer place and they re positioned the spring seats for $ 100. easy fix and the new axle fit perfect

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You should have went to eastons. They have them custom made to fit, with the mounts installed, and EZ lube hubs for cheaper than the crap princess auto axles with no mounts, and standard bearing sets. 

S. 

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6 hours ago, Sinker said:

You should have went to eastons. They have them custom made to fit, with the mounts installed, and EZ lube hubs for cheaper than the crap princess auto axles with no mounts, and standard bearing sets. 

S. 

I ordered from Cerka.  I reached out to Eastons; but they didn't bother getting back to me.

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16 hours ago, John Bacon said:

I ordered from Cerka.  I reached out to Eastons; but they didn't bother getting back to me.

Did you call? These are real people, who work all day, Id bet they rarely get on their email or website, but if you called they would hook you up. 

Cerka is good too. My neighbor has a cerka trailer that i love. 

S. 

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Worrying about weld on spring perches is a non issue. Assemble the spring pack, perches, mounts and U bolts. Adjust axle position and tighten it all down. If the trailer tracks properly; stop at most any garage that has a welder. Have them weld the spring perches to the axle. For a road test with things just bolted together, will be fine. Have it welded for longevity sake  

Dan

Sorry forget to add that your road test could take you to London? I’d be more then happy to weld it up for you. 

Edited by DanD

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On 8/17/2019 at 7:11 AM, DanD said:

Worrying about weld on spring perches is a non issue. Assemble the spring pack, perches, mounts and U bolts. Adjust axle position and tighten it all down. If the trailer tracks properly; stop at most any garage that has a welder. Have them weld the spring perches to the axle. For a road test with things just bolted together, will be fine. Have it welded for longevity sake  

Dan

Sorry forget to add that your road test could take you to London? I’d be more then happy to weld it up for you. 

Thanks for the offer.  I don't think it will be required though.  They make the axles to order; and they request the centre to centre spring measurement.  So, I am expecting it to have the perches already welded in the correct location.

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Thanks for all of the advice.  The axle fits like a charm.  I got my first fish since installing the new axle today.

Can anyone identify the species?  

IMG_20190831_174114.jpg.bddef77e2595914956b6caa8485f6f47.jpgIMG_20190831_174124.jpg.83f16ee40c7100a38bdcdf17dea10c01.jpg

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