Trailer spring over axle mounting tips
 

Hi all, I have been reading through your trailer build threads & would like to offer you some suggestions regarding axle & spring mounting. I don't want to come across as a bighead, but I build trailers & my ideas have proven to be reliable.
Many off road trailer have the axle mounted under the springs for extra ride height. Many off road caravans using leaf springs do the same. After performing many road side spring replacements on customers trailers & vans, I thought I would share my ideas with this community.
The axle pad is the piece of steel that is welded to the axle to locate the springs. When the springs are located above the axle, the axle pad should be longer than usual to support the spring better. I like them to be 100mm long. Also, remember to turn the centre bolt over so the thread & nut faces up. You don't want the centre bolt to contact the axle. Obviously, when the axle is fitted under the springs, the fish plate (aka the U-bolt plate) is at the top. If tightened down in that position, it will cause the spring to flatten out as it is contacting the spring at the ends of the plate. The better method is to weld a standard sized axle pad to the underside of the fish plate. That way, when it is tightened down, it will clamp the spring tightly without pulling the set out of the spring. 90% of the broken springs I have replaced were caused by the u-bolts coming loose as the spring was compressed over bumps etc.
I have never had a spring breakage after performing this simple mod. It is also a good idea to fit 5/8" u-bolts to any trailer used off road. Very cheap insurance when travelling in remote areas...

Sounds like a sensible approach to me.

Jason

Thanks for the tip mate, have you got any pics?

I'll try & take a couple over the weekend. I'm doing some work on my daughters trailer at the moment & I did the U-bolt conversion 5 years ago. I'm also fitting a telescopic drawbar to it so she can tow behind her new Prado & still fit it in the shed.