The Use of Stabilisers

Stabilisers are not intended to be a substitute for sound practice in loading and towing.  They are valuable, particularly with caravans and horse trailers, and other high-sided trailers. They will not, however, overcome problems created by poor loading or poor driving.

• Set up the trailer so that is level when coupled to the towing vehicle.
• Make sure the nose weight is between 50 and 100kg (unless trailer is very light.)
• Make sure the tyre pressures are correct.

It should be remembered that you must not travel in the right-hand lane of a motorway, with three lanes or more, if you are driving a vehicle drawing a trailer.

The main purpose of a stabiliser is to stop a trailer or caravan from becoming unstable and '"snaking" from side to side. They come in various forms and designs. The most popular types are the trailing arm leaf spring and the coupling head stabiliser.

"Snaking" is when the axles of the caravan/trailer move out of line from the towing vehicle.  When this happens, the trailer/caravan tries to move back into line and it goes too far. This action starts the cycle of "snaking" from side to side. Unless the snaking is stopped, it will increase and will cause the driver to lose control.

Snaking can be caused by a number of factors such as:

• Incorrectly placed loads (excessive loading to the rear of the axle(s))
• Very light or negative nose weight
• Side winds (when a large commercial vehicle or coach overtakes and causes the air to buffet the caravan/trailer, moving the axles out of alignment)
• Special purpose built trailers having awkward internal fixtures that may be not balanced, causing instability.
  

To stop snaking there are a few simple rules:

• Keep the vehicle steering in a straight line
• Change down a gear and take both feet off the pedals
• If the snaking starts whilst going down hill, change down a gear and very gently apply the brakes
• Do not try to accelerate out - this could end in disaster unless the vehicle is exceptionally powerful.
• Do not brake hard - this may cause the trailer to jack knife.
• Do not try to steer out - it is very difficult to read the snaking action and it can make it worse.

Stabiliser Checks:
(Each manufacturer will have their own servicing and checks guide, which should be contained within the handbook or fitting instructions.) Stabilisers must be checked at the start of each journey

• Check that the friction is apparent (if possible)
• Check that the stabiliser fits into its locating place properly

Stabiliser Servicing:
Stabilisers must be overhauled thoroughly at least once a year or after 20K miles towing. (whichever is sooner). The stabiliser must be dismantled and any pads or friction disks must be inspected for cracking or excessive wear. NB: Beware of servicing older stabilisers because the friction pads or disks may contain asbestos. These should be handled and disposed of carefully 

Problem	Cause	Remedy
Groaning noise when manoeuvring slowly	Friction material migrated onto adjoining metal parts	Dismantle and clean metal parts
Leaf spring jumps out of chassis shoe	Tension on disks too high	Check and reduce operating tension
	Incorrect position of chassis shoe. Leaf catching A-frame	Check for full articulation and move chassis shoe