Trailer Troubles

If you had it happen out in the desert Willem it may have been left on the collection pile for them.Lol
At least you can now as you have stated go back to the original set up.
Cheer's Rob.

Over-slung or under-slung suspension is quite normal body building practice so I don't consider what you did by putting the spring packs above the axle to give more bump clearance would have caused the component failures you mention. The only additional load you created was the centre of gravity would have been a bit higher. I am assuming are not overloading the trailer and that you replicated the original design in terms of drilling the axle to locate the spring centre bolt or used a packer plate between the spring pack and the axle drilled in the centre to achieve the same thing. If you used a packer plate did you tack weld it front and back after you had centralised the axle relative to the trailer width because this is the only way you can stop the axle moving sideways apart from the clamping force of the 'U' bolts which is not what they are designed to do. The 'U' bolts are only there to clamp the spring to the axle and prevent vertical movement as opposed to horizontal. Don't forget there are 'U' bolts and there are c..p 'U' bolts so make sure you use larger diameter ones with close fitting holes in the plates and that the plates are thick enough that when you pull the 'U' bolts up tight the plates don't bend. Also make sure the 'U' bolt material is quality steel with a good thread and that they are fitted "square" to the axle so when you stick your head underneath for a look-see they are not leaning over on an angle. The fact the shackle pins & bushes had play in them makes me think this might have had more to do with the parts breakages than the mods you did. The going must have been pretty rough to cause wear in those parts after 20000km but in any event the play in those parts would put extra load on the 'U' bolts and centre bolts every time you hit a bump as the whole assembly is not firmly held together. Any wear you get between parts creates shock loading when you hit bumps resulting spikes in the forces generated which are well above the design criteria and safe working load of the components. I would fit greasable replacements and maybe a set of decent shockies if you don't have them already. At least with this type of suspension as well as causing less failures than the trendy trailing arm independent type you are able to repair it on the roadside if necessary with a basic tool kit (coupla shifters, big hammer and a drift) and a minimum of parts. You can improvise using HT bolts in lieu of 'U' bolts, tie the spring to the axle with fencing wire and even replace a spring pack with a length of timber if necessary. You can't do any of that with a trailing arm set up but if you are going to really rugged country I would carry few spare 'U' bolts and a spare spring pack and on that point it may pay to ensure the spring rate and capacity is correct for the type of work you are doing.

Willem,
as stated, lucky you found it where you can fix it, and at least you are smart enough to check your trailer for maintenance before you travel. I am always amazed at the number of travellers you see out there having trailer troubles along the side of the road. Some manage to spend thousands on their vehicles but forget about the poor old trailer hanging off the back.

I learnt my lesson the hard way when I was with the Northern Territory Emergency Services at Ayers Rock many years ago. I took one of our recovery Trailers out into the middle of nowhere and managed to break a leaf spring. I was able to temporarily relocate it with some chain dogs but even this simple job was a lot of trouble in 47 degrees.

For me, I give my trailer just as much attention before a trip as I do everything else.

Toytruck

We had one of the 2 U bolts on left side of our trailer break and fall off and one on the right side also partly break while on the Mereenie Loop road. This allowed the axel to move sideways and the first we knew that we had trouble was the loud bang as the tyre rubbing on the side of trailer blew out.

It was a costly exercise driving to Alice Springs to hire a tandem car trailer and return to pick up the camper trailer.

You were very lucky to have found it at home.

Willem, I think most people would be suprised at how much wear there is on the shackles and spring bushes if they ever bother to take them apart and actually have a close look at the bits you can't normally see. Just because a shackle may be of the non-greasable type does not mean that the pin is not being worn away inside. I think that 20,000 km is a great distance between overhauls for a trailer. Also some couplings have bolts that should be pulled and checked for wear every few years.

Willem
As has been stated the springover shouldn't cause any additional wear, our Cub camper has been this way for over 30 years. I also did a spring over on my garden variety box trailer with no ill effects. If I was you I'd replace the shackle pins with hardened greasable ones, fit good quality spring plates and U bolts, replace the centre bolts and put it back together.
I second the tip to make sure the spacer plates locating the axle where the spring sits should be welded onto the axle to prevent sideways movement.
Shocks will also help.
No slipper springs only use eye to eye, too much load on the sigle eye with slippers for rough terrain use, you will eventually snap the front eye.

G'day Willem,

Funny thing is I was thinking about you on Sat night as we sat around the tent at Kings Canyon looking at our Modern Trailer and wondering about the spring over you did. At the time I came to the conclusion the bit of extra clearance would be good but for the effort I don't need to stress. Especially as the way it is now, it sits perfectly level with the car.

Thanks for the heads up, I just went and gave it the cursory once over and nothing seems amiss, I'll lift up the trailer with the suspension hanging this week and double check it all.

I believe the hammering that you have given that trailer is probably the worst case scenario that Modern had ever envisaged.... Maybe you should setup an equipment testing service LOL.

Have you come to any further thoughts/conclusions about the cause? Is there any chance that the u-bolts were over torqued? Although as I write this I'm thinking it doesn't explain the worn bushes.

Anway good luck with it and let me know how it goes.

Thanks and Regards,

Slammin.

sorry to say but all the breakages are normal for leaf springs, even in the heavey transport industry running on bitumen they have the same problems, as for of road trailers u cant go past indepenant suspension with coils and shocks, have done over 80,000ks and have never broken anything, unlike the many leaf trailers i have travelled with both new and old and modified. Col

Following up on my report I found that the spring bushes were OK and just needed tightening. Still, it took me most of the day getting just one spring done. Broke two of the Helper Spring fastners and buggerised around for most of the day going to the hardware store and back and in under the trailer which is up on 4x jack stands. Pretty stressful for an elderly body....lol. Some VB's are helping me relax tonight and will tackle the next spring tomorrow. Think I will set the trailer up again as original with the springs under the axle.

Thanks for all your ideas

Cheers