Trailer Maintenance... Axle U-bolts.

[FishStyx]

On Saturday afternoon after work, I snuck off to my local  dam for a few hours of hunting bass. As I got out the bakkie back at home  (after dark) I could smell a whiff of burnt rubber. I walked round the bakkie  and trailer and saw nothing amiss. On Sunday, I cleaned the boat and saw some  rubber granules on the right hand side of the boat and trailer. On closer inspection,  I realised that the axle had shifted sideways and the tyre was rubbing against  the trailer frame.

I had never even thought to check the U-bolts that hold the  axle to the leaf springs before. Fortunately it was only a few km between the  dam and home. A longer trip and it would have shredded the side wall of the  tyre.

I took the wheels off, slacked off the U-bolts and re-centred  the axle.


So it’s definitely something that should be on your checklist  when you do a trailer check before making your next schlepp down to the coast  or wherever.

[REEFMAN]

Jeepers  that could have turned ugly...!

[dugong]

 I had that years ago in Mozambique with a heavily overloaded SkiVee and we shredded a tyre!! Isn't there a locating hole on the newer axles?

[FishStyx]

Isn't there a locating hole on the newer axles?

Not as far as I'm aware of... There are too many variables in the designing of trailers for it to be practical. There is a locating pin (it's the extension of central rivet in the leaf springs) that locates in square bracket through which the U-bolts fasten... Can be seen on the bottom pic. The axle is held laterally purely by friction of very tight U-bolts, but there would be nothing to stop a builder welding tabs on either side of where the springs attach to the ale.


When I was sorting it out, I found that my U-bolts were actually far from tight... I wondered whether I'd failed to tighten them sufficiently when I built the trailer or whether they'd worked loose over the last 3 or so years that I've had it in service. Best tho is to just check them once in a while... Maybe when greasing bearings every year... Cos we all do that every year... don't we 

[dugong]

Yip now that I think of it there is a hole in the square locking plate nothing on the axle.

[FishStyx]

Yip now that I think of it there is a hole in the square locking plate nothing on the axle.

There is also a small square spacer plate (about 10mm thick) with a hole in it between the axle and the springs so that the rivet through the spring doesn't sit against the axle... I reckon if one welded that spacer onto the axle in the right spot, your plan would materialise. 

[Nooduck]

Most axles have a hole for the centre bolt of the springs, but then again so many manufacturers so many different designs.


If you weld the square plate just weld parallel to the axle and NOT across it.

[FishStyx]

Correct Nooduck... I would recommend just tacking the corners. The U-bolts will do 99% of the work.

[Rory mundy]

On my axle it came with a spring hanger that goes over the axle once everything was centered and squared you weld them on. Pretty important on a round axle that has breaks or when breaking the hole axle can turn in the u bolts

[FishStyx]

On my axle it came with a spring hanger that goes over the axle once everything was centered and squared you weld them on. Pretty important on a round axle that has breaks or when breaking the hole axle can turn in the u bolts

I never thought about round axles with brakes but that does make perfect sense. Do they offer any special instructions with regard to the welding to avoid weakening the axle at the points of the welds?

[Rory mundy]

most axles for lighter weights are solid bar so you can weld properly with my axle wall thickness is 8mm i think so you can weld it no issue aswell there should never be any flex on a axle to crack the welding will see if i have a photo some were

[Rory mundy]

like this

[FishStyx]