The main function of the Spacer-Tech Bearing System is to fit between the inner taper bearings (cones) and to hold them at a set distance apart. This then allows the axle nut to be tightened and not 'backed-off', ensuring both inner bearings, races and spacer are held tight on the axle. The Spacer features an adjustment that involves the body being internally threaded at one end and the inner ring externally threaded. As the Spacer is adjustable, it can also be calibrated to micrometer accuracy - to 0.0015 of an inch! Each Spacer is engraved with the measurement procedure, part and patent numbers.

Our primary priority in designing the Spacer-Tech System was not to interfere with the axle or hub in its original form. Careful consideration was given to the weight of the spacer as it is considered unsprung weight, therefore we use high-grade steel for optimum strength to weight ratio.



We have been overwhelmed by the widespread, world-wide, interest in our Spacer-Tech adjustable bearing system. Fleet owners who initially purchased the system for one truck are now requesting their entire fleets be fitted!

Spacer-Tech's bearing spacer system must be completed with a heavy duty axle nut – either the Castle axle nut or the Stemco Pro-Torq axle nut. The torque settings for the axle nut is 600ft/lbs after the spacer has been set to give a .003" to .005" end float. The spacer can be used with either oil or grease lubrication to lubricate the axle bearings.



Many American and Australian made axles use a two-nut retaining system for bearing adjustment and hub retention. This nut type is only 8-10mm thick and is not considered adequate for the torque required to effectively assemble a hub with a spacer. Unfortunately though, there have been many failures with hubs and wheels actually coming off as a result of the locking arrangement used with the two-nut system.

The Castle Nut System are hardened nuts which incorporate a unique, patented locking system, allowing the fitter to generate enough pressure to obtain the 600ft/lbs needed to seat all the components together without fear of the axle nut tool slipping.