Checkpoint® is a loose wheel nut indicator that is used extensively by the transport industry as an enhancement and development of fleet safety roadworthiness procedures, daily walk-round inspection and defect reporting and scheduled maintenance requirements. Its use allows accurate monitoring for loose wheel nuts and helps prevent wheel hub damage or the loss of a road wheel should a wheel nut loosen. An additional safety feature of the Checkpoint is its heat sensitivity, when higher than normal operational temperature are reached the Checkpoint is designed to melt indicating an imminent bearing failure or braking issues.

Application

The Checkpoint® is fixed to the wheel nut by gripping the six corners of the hexagon of the wheel nut. When the wheel is being fitted out the Checkpoint pointers should be aligned and set in a recognisable pattern. Should a wheel nut loosen off, the Checkpoint® has no option but to move with the nut and so break the recognisable pattern that was set, thus indicating the wheel nut has begun to rotate and therefore to loosen.

Sizes, Range & Colours

Checkpoint® is available in an extensive range of sizes and in two standard stock colours, yellow and red. Other colours are available to special order.

The current available sizes are:

The size refers to the 'across the flats' dimension of the wheel nut hexagon in millimetres.
A simple and accurate means of measuring the wheel nut size is to use an un-worn socket as it is important that the correct size of Checkpoint® is fitted to the wheel nut.

They should be a tight slide fit down to the washer of the wheel nut or wheel hub face leaving a small nominal (say 0.5 mm) air gap between the two surfaces.                     

Material Grade & Care

Checkpoint® is manufactured from Polyethylene. This special grade is suitable for heavy-duty applications such as high load urban duty cycle service or where full axle loading is the norm.

The material used is a virgin polymer and is UV stabilised. It is therefore dimensionally stable. The polymer does not degrade in sunlight. Checkpoint® can be cleaned using any of the available vehicle cleaning agents, detergent solutions or paraffins.

Checkpoint® are not attacked by road salts or petrochemicals. The pointer being large, it is highly visible even when coated with road or operational grime.

Fitting

It is recommended that the initial fitting out of the vehicle is done in the course of scheduled maintenance or during a roadworthiness inspection or when a wheel nut torque check is scheduled.

The wheel nuts must be torqued to the recommended value before the Checkpoints® are fitted.

The Checkpoint® should be a tight slide fit onto the wheel nut without the need for tools or any other assistance. This is also the case when there is a need to remove them.

Fit the Checkpoint® so that the raised rim of the collar is outermost from the wheel nut washer, or the profile of the wheel. This eases removal by giving a finger purchase on the collar rim of the Checkpoint® without damage.

The layout pattern used for the Checkpoint® on the wheel is of personal choice; it is often dictated by the wheel rim size and profile, and/or the PCD of the stud.

The most commonly used patterns are:

Any patterned configuration may be used so long as the movement away from the set pattern of one or more of the Checkpoint® will be clearly visible on inspection.

safe	unsafe

It is important to remember, when arranging the pattern you will use as the layout for the Checkpoint® on the wheel, that should a wheel nut loosen off, the Checkpoint® pointer needs room to move to indicate that the wheel nut has moved; this is normally anti clockwise. The length of the pointer should not therefore be aligned against the wheel rim profile, which could restrict movement.