Thread: Trailer suspension help!

Another question from this i suppose would be - if a trailer has a tare of 980kg and is unloaded with this kind of suspension, would you expect it to bounce around and be rough?? I have been in the back of a float with leaf suspension as it was not that bouncy or loud.

i assume its a tandem.....if you jack up one wheel you should be able to watch the suspension flex, this will give you some idea

does the seller have a quad or motor bike you could ride up the ramp to see how the suspsion works

Im assuming that the float has something similar to the Al-ko IRS (independent rubber suspension?). As i understand it this suspension only operates correctly if it is within 100kg of the weight rating.
If outside of the optimum operating weight (no horses in the float) it would be very stiff.

With some more weight I would expect it to be a little less rough.

The IRS tends to be pretty reliable but i would be interested in whether or not the rubber has perished? It would be worth having a look at

I haven't seen a float running this suspension before though? is it a custom build?

That's not a bad idea, my dad has a motorbike we could ride up there, not sure he would be too impressed about taking it for a drive though!
We can at least drive one side of the float up a few bricks and get some idea.

I don't know what brand the float is, however Tuza Floats out at Mulgoa (between Luddenham and Penrith) make floats with rubber torsion bar suspension and will do inspections on floats (at least they used to) and will do repairs.

The good thing about the torsion bar system is that it allows a very low floor to reduce the centre of gravity of the neddies in the back as far as possible. The bad thing is that the swing arms can suffer damage from median strips in inexperienced hands.

What you should do is lift each side of the trailer chassis (in turn) so the swing-arms are off the ground and check the attachments of the torsion tubes to the trailer chassis and the swing-arms for looseness. If the swing arm rattles in the mounting tube it needs to be replaced. Also check alignment with a straight edge between each wheel on each side also draw an extended line on the ground, move the trailer out of the way and measure for differences between the alignments across the trailer. (Addit: I would probably mark the centre line of the tow ball with a plum bob, just to check that the trailer wheels were tracking in line with the tow vehicle. The distance from the tow ball to the centre of the axle/hub centre on both sides should be the same or very very close.)

My brother loaned his Tuza to some friends who in a single trip Nowra-Sydney and return trip, managed to bend one torsion bar to the extent that it had to be replaced. The symptoms were directional instability where the trailer wouldn't track straight.

That makes sense with the weight rating.
It's an imperial float - I gave them a ring this morning to ask about it, they weren't particularly helpful but they did say that all floats in 2007 had that suspension. Apparently Tuza and another brand (can't remember the name at the moment) also use the same suspension.

Is there a way to determine whether the rubber has perished without taking it to a mechanic? I'm not sure the seller would be keen on me driving it off to a mechanic!

I am not familiar with this suspension, but in my opinion, perished rubber is very unlikey - it is protected from UV, and the thick rubber is very unlikely to have been contaminated by oil except on the surface. I believe that problems with the suspension are more likely to be due to damage to the arm (as suggested above) or possibly a whole suspension unit is loose on the float. I would follow the suggestion above to jack up each wheel separately, and thoroughly examine the suspension, removing each wheel if necessary.

Or even better, find someone who is familiar with this suspension and pay them to check it.

John

Thanks everyone for the advice, I am happy with the type of suspension and I'm hoping that the sound was just because the float was unladen. I'll head out and have another look and take someone who knows a bit more about the suspension.
Lotz-A-Landies - do you know how much the replacement cost? I'm assuming that would be the worst case scenario and hence the most expensive.