Trailer Suspension
As I mentioned in an earlier article my Jarcat trailer was built to Ross’ plan including Al-Ko suspension. I did change the wheel size though, I don’t like those little 10” wheels. They’re expensive, the tyres are not cheap; also because the wheels are so small they spin very rapidly at highway speeds shortening bearing life and they fall into quite small pot holes.
I bought three 13” (ex Torana) alloy rims from a wrecker quite cheaply. Quite often in an accident one wheel will be damaged meaning the three left can be bought cheaply.
I also made a common mistake and bought three second hand tyres. Silly really as at that time the boat was worth more than the tow car! Buy decent tyres for the trailer, I learnt my lesson with two cheap tyres written off, luckily without any other damage.
Back to the suspension. The Al-Ko gives a nicely damped ride and sits the trailer low to the ground. However Jarcat owners from places in the far north advised me that they failed regularly in hot conditions on rough roads.
Spring slipper mounting.
We did a few trips to the Gippsland Lakes in the cooler parts of the year and the suspension worked beautifully. Our next long run was in summer up to visit Mike K in Gosford. Shortly after arriving I kept feeling jerks from the trailer on small bumps. Inspection showed the left tyre was rubbing on the underside of the guard. Dropped the boat in the water and went and had a couple of 20mm thick alloy spacers cut and drilled and fitted. The problem re-occurred a few years later. This time I was near home and made up spacers from 50mm heavy gauge RHS. I should have replaced the suspension then as it had now sagged down a good 40mm from original.
In January we were invited to enter the Milang to Goolwa race in South Australia. Almost half way there we pulled over to find a place to stay and as we slowed we became aware of a strange noise linked to road speed. A sort swoosh-click. On checking the suspension had collapsed to the stage where we’d completely worn the tread off the trailer tyre and had gone right through the wire cords in one spot (the click)! Also generated enough heat to de-galvanise the guard and burn my hand when I bent down to inspect the tyre! Noticed at this time that the swing arm was canted in at the top – the other side as well but not so badly. Arranged to leave boat and trailer at the caravan park in Kaniva. In hindsight I should have dropped the boat off the trailer and brought the trailer home.
Underslung spring – extra plate to take locating pin on spring.
Decided to do as suggested by other Jarcateers and replace the complete assembly (after all 18 years is not a bad life). The Spartan single leaf spring kit was a good fit according to those that have fitted them. Had to wait a while to get a long enough axle made up plus work out how I was to attach the mounts to the axle without a welder on site (or a power point within 40m of the boat.) At home I welded up mounts to bolt on and gal sprayed them.
When all ready I took all the bits and tools I though I might need and drove back to the boat.
The springs mounted perfectly with the wheels located exactly where they had been.) I had to drill two holes through the front mudguard support for the front bolts on the eye plates. That was it. Paid my debts to the lovely folk at Kaniva (the very helpful owner of the local bus depot for the loan of axle stands and trolley jack and the management of the pool and park) and hit the road.
Spring eye mounting.
Due to the uncertainty in my mind as to just how well it all would hold up I sat on about 80km/hr and pulled over frequently to crawl under and check everything. (No problems). One moron tailgated me sitting less than 2m from the back of the boat and would NOT pass (so close I could see him under the hulls). I eventually pulled over and stopped to allow him pass. Caught up with him later doing the same thing behind a B-double.
On getting home trouble free I found the rig was too tall to fit under the carport. Checked with Spartan and they said no problems underslinging the springs so I went and bought a couple more adaptor plates and longer U bolts and did just that. Now it’s about the same ride height as original and tows just fine. As the U-bolts that hold the axle to the spring are now in tension all the time I didn’t tighten them as much as I would normally (about 45nm) but fitted stainless Nylocs and used Wickin Locktite on the threads. (A spare set of U-bolts and nuts will be part of the travelling kit in the future just in case, along with the globes, wiring plug and a spare bearing assembly I usually carry).
