The best mechanical changes you can do to keep your van reliable on tour.
While it’s true that a caravan doesn’t have mechanical components – there is no engine or transmission – there are parts that can fail if you don’t keep them updated.
A caravan’s running gear is very basic, yet the number of things that can and do go wrong might surprise you. Usually it is a lack of maintenance. The trap that is easy to fall into is to focus too much on the tug’s maintenance and worn parts replacement and to ignore the caravan. A caravan’s running gear will wear out too.
Whether you tow your caravan on good paved roads only or you like to explore outback dirt roads, the moving parts do wear and are prone to failure. Even if you’re not using your van often, you might find that components still deteriorate. Replacing them is cheap insurance.
If it has been a few years since they were fitted, fresh, top quality, greased wheel bearings are a good starting point. This is one part that is often the first to let caravan owners down. Bearings should at least be regreased and adjusted before any big tour, and it is always a good idea to carry a new spare and split pin.
Get some good quality bearings like Timkin rather than a cheap Chinese brand, and make sure that the axle spindles are not damaged with score marks when you’re replacing the bearings. You should have greased all through the bearing and not just the outer surface. The correct tension
needs to be applied to the axle nut. If you’re unsure, get the job done professionally.
An early warning sign of bearing failure is that they get noisy. They can also let go altogether and the whole wheel and hub assembly can detach from the axle. As you can imagine if that happens on the road, it is not a pretty sight.
SUSPENSION & BRAKES
While at the wheels you can inspect the suspension springs, bushes, spring hangers and dampers (if fitted) for damage, and make sure the suspension is properly greased if required.
After bearing issues, one of the more common problems out on the road is the brakes. You should adjust the brakes so the vehicle and the van are sharing the load. Be aware that this adjustment might be different for around town versus trips out on the open road.
The problem is if you rely too much on the van brakes they can overheat and cause the brake shoes to score and crack or glaze. If the brakes heat up the hub sufficiently, the wheel bearing can boil out and then you have a second problem – a dry bearing, which will eventually seize or fall apart.
A good pre-trip inspection will also check the remaining brake pad or brake shoe material thickness. You also need to make sure the brake drums have not scored and there is no oil or grease on the linings. Replace the pads or shoes if there is any doubt they might not last the distance of your tour, and get drums replaced or machined if they are scored. The same applies to brake magnets. While usually reasonably long lasting, they are relatively cheap to replace if there’s any doubt about their serviceability. One test is to check the magnets’ wires with a voltmeter. They should show 12V with the tow vehicle engine running and the electric brake controller slide applied on full. If there is little or no c\voltage, there is a problem with the controller, magnets or wiring that needs to be fixed.
When tightening the wheel nuts, make sure the threads are not worn or damaged. It might be a point of contention, but I suggest you do not oil or grease the threads. Just make sure they are clear of grime and grit. Always check the tension of the wheel nuts when on tour. It’s a good idea to do a shakedown run on a local stretch of highway before the big trip, so that you can check all your good work (or your mechanic’s) won’t be undone.
Another potential problem is the caravan’s park brake. You want this adjusted enough to hold the caravan when parked, but not too tight. About 20mm of slack in the park brake cable is about right, depending on the run of cable. Always check the wheels as well, as no cable park brake operating on drums is overly effective.
Greasing the coupling is a good idea to stop noise and reduce friction and heat build-up, but you can have problems with securing the coupling if too much grease is applied. You may think it’s secure, but the excess grease will mean the locking pin hasn’t engaged and the coupling will detach from the ball when on the move. Use the grease sparingly or better still, use some dry-lube on the ball each time you’re hitching up for a long trip. Don’t forget to also lubricate the friction points of the load-levelling hitch, if you use one.