The equipment needed is; -
A 1 meter long spirit level,
2 off 350 mm magnetic spirit levels;
A torque wrench able to pull over 200 Nm
A Socket set
Three or four axle stands.
Various shims , ( 3-8 mm thickness worked for me )
A trolley jack.
A tyre lever.
A small magnet attached to a short length of light string with a small weight ( I used a 6 mm nut ) on the end of the string
Okay park the trailer on a flat hard area and relieve all the wheel nuts. Put the meter long spirit level across the "A" frame to gauge the lateral level.
Jack up the trailer fitting the axle stands on the chassis rails both sides and using the jack and the shims between the chassis rails and the stands ensure that the trailer is level left to right (lateral).
Remove the wheels and put the magnetic levels on the wheel drums (or discs) with the horizontal bubble uppermost.
Okay, to adjust the camber angle, that is the degrees that the wheel(s) lean in or out. They should be perfectly vertical = 0 degrees.
To adjust this, if adjustment is necessary, loosen the outer "cam" bolt on the suspension "A" frame and turn it so that the bubble(s) are showing that the drum/disc is perfectly vertical ( 0 degrees ) re-tighten the nut to specification, on my trailer that is 140 Nm but some trailers call for up to 160 Nm.
Toe-in. This is adjusted by the inner of the two bolts on the "A" frame. Again this should be zero millimeters.
To measure this again use the magnetic spirit levels only this time turn the drum/discs so that the level is horizontal and measure from it to the chassis rail, both the front and rear measurements should be identical.
My drums are 12" so to carry out this measurement I had to slide the magnetic level across the face of the drums to take measurements from the front of the drum to the chassis and then to the rear.
If the measurements are equal there is no need to do anything else. If the measurements are different and by this 1 mm is enough to cause considerable tyre wear on bitumen loosen the inner bolt / nut on the "A" frame and using the tyre lever lever the "A" frame at the trunion bush so that they are equal, then re-tighten the bolt and nut gradually constantly checking that the measurements are the same and that the toe-in hasn't changed, again tighten to the specified torque.
My "trick" for this is the magnet and string. I put the magnet on the chassis rail and drape the string and its small weight over the horizontal spirit level, ( ensure the string is taught, ) and I put a small paper tab marker on the string after the magnetic spirit level so that the slightest change in distance can be easily seen as the inner nut and bolt are re-torqued.
From past experience, and as we will be travelling on well over 4000 kms of dirt tracks on our return from WA, I'm expecting to be having to check these at least twice mid-tour.
To fail to check them regularly can lead to disaster as I found out as per my photo. This photo is of my drivers side cam-bolt - less the nut that sheared off !!!
- cambolt.JPG (514.74 KiB) Viewed 27 times
- cambolt.JPG (514.74 KiB) Viewed 27 times
As a relative newby to off-road camper trailing what I failed to appreciate is that on trailers such as mine with a GVM of 2350 kg each of the two wheels is loaded with more weight ( 1,175 kg each ) than any of the four wheels on the towing vehicle. My Wildtrak, with a upgraded GVM has a fully loaded weight, including the tow ball of 3460 kg so each wheel is only carrying 865 kg. ergo each of the trailer wheels are having to carry 310 kg more than those on my Wildtrak.