Arresting the shoe creep

One of the long-standing bugbears of heavy truck and trailer operators – the dreaded shoe creep – has been effectively stopped in its tracks by the innovative Tru-Shu product.

It’s the bane of many a truck operator, seeing up to 10mm, or even more, of the brake shoe on drum braked vehicles hanging out past the edge of the drum rim.

This phenomenon has dangerous consequences as it causes reduced braking performance due to the reduction in contact area between the lining and drum.

What’s worse is that it’s a self-generating issue. As the shoe rollers move out of line with the S-cam, more force is exerted on the inner side of the shoe, exacerbating the tapered lining wear which, in turn, reduces braking performance.

Given this, it’s little wonder that roadside transport inspectors are quick to slap a defect notice on vehicles displaying shoe creep.

Tru-Shu is widely used by TMC Australia, a manufacturer of special purpose trailer axles for the transport, mining and agricultural sectors. The business was founded in 2001 and has occupied the current workshop facility in Hallam, Victoria since 2004.

The range of axles TMC produces includes disc and drum braked models for 17.5”, 19.5” and 22.5” wheels and because they are mostly locally built, they can be made to suit any application and at any required track length.

In the majority of cases, the axles are supplied as a package with either leaf spring or airbag suspension. In the case of the air suspension offering, the company specialises in low-profile set-ups for 17.5” and 19.5” wheels with a fair amount of customisation for quad-axle combinations and to suit rear self-steering axles.

Speaking about the Tru-Shu product, TMC Australia Operations Manager, Alex Law, explains that Tru-Shu is fitted directly onto the existing brake shoes, physically eliminating any opportunity for outward movement.

“Tru-Shu keeps brake components including shoes, camshafts, rollers and return springs better aligned and eliminates the problem of brake shoes ‘walking’ out of the drums due to heat and expansion over time,” Alex says.

“It facilitates even brake lining wear, which ensures longer service intervals and lower maintenance requirements, therefore reducing downtime.

As a result, Alex explains, Tru-Shu equipped brakes retain optimum performance over their entire service life.

The result for truck operators is increased brake component life and reduced brake defects, as the product prevents camshafts from hitting the drum in the event of a camshaft circlip or brake spring failure.

Other benefits of Tru-Shu are that it keeps brake shoes in good condition for relining and prevents anchor pin ends from taking undue point loading due to brake shoe misalignment.

In terms of which equipment can be fitted with the Tru-Shu brake shoe alignment system, Alex says the company tends to concentrate on special-purpose axles in the capacity range of nine to 20 tonnes, with the product often custom built to suit heavy-duty, off-road and arduous applications.

“Tru-Shu brake shoe alignment devices fit directly onto our existing brake shoes ‘Q’ or ‘P’ brake – with 420 x 180, 335 x 210 or 420 x 220 brake sizes,” Alex explains.

“Because Tru-Shu brake shoe devices are designed and manufactured in Australia, parts and support are easily accessible, while the device allows for minimal parts to be used and ease of installation.

“In various types of rugged terrains, whether to and from a mine site or in the outback, the Tru-Shu addition significantly enhances brake integrity and service life,” he says.

“In fact, positive feedback we have received from fleets, service centres and end users suggests Tru-Shu saves transport operators thousands of dollars in replacement costs. “This product has the potential to significantly increase the service life of brake linings in most applications, including harsh outback terrain.”

One company that swears by Tru-Shu is All Size Equipment Transport (ASET), a South Australian based company that specialises in the haulage of over-dimensional equipment and machinery, and was, in fact, the inventor of the Tru-Shu device.

Since 2006 TMC has partnered with ASET in the development and testing of braking technology products.

“We have been working with ASET for more than 14 years, says Alex. “The ASET transport operation uses many of our TMC 19.5” axles, mostly equipped with our nine-tonne LMV low-profile airbag suspension. The relationship is mutually beneficial. On several occasions we have co-operated with ASET on product design improvements, which were put on trial with ASET before we released them to the rest of the market.”

Emphasising industry acceptance of the innovative system, Alex says TMC recently equipped a complete fleet involving 120 wheel ends with the Tru-Shu componentry.

“The feedback has been most encouraging,” he concludes.

Fast Fact
Australian trailer axle manufacturer TMC says the Tru-Shu system maintains the correct alignment of brake shoes which prevents them from ‘creeping’ out of the drum. The company claims this can significantly increase the life of the brake linings.