Precise Measurements

Now more than ever, components such as differentials are being tailored for specific applications. Collins Transport has found Meritor’s pumpless MT23-165G drive axle to be a winner in its Kenworth linehaul prime mover fleet.

Over the years, the development of truck differentials eventually led to the inclusion of a lube pump in the interests of providing superior lubrication of the inter-axle differential (IAD) located at the top of the front diff housing in tandem drive assemblies.

This was deemed desirable for trucks in vocational applications where lower speeds mean less splash lubrication reaches the IAD compared to highway operation, potentially reducing its lifespan.

It was also assumed, apparently with something of a one-size-fits-all mindset, that this system would indeed improve the lubrication and lifespan of diffs in on-highway trucks, but subsequent operator experiences have proven this to not be the case.

What they discovered is that the extra friction caused by the forced-feed circulation of the oil heats it to a higher temperature during long haul trips.

This combined with high ambient temperatures can be detrimental to the life of the oil and, in turn, the internal components of the differential assembly.

In other words, when a truck is travelling consistently at highway speeds, splash lubrication of the IAD is more than adequate and a lube pump is not required.

Based at the Adelaide suburb of Wingfield, Collins Transport is a family-owned and operated concern founded in 1965 by John Collins.

John started with a Dodge five-tonne tray truck that he drove himself, carrying produce between Adelaide and Melbourne.

From that time forward John and the company he spawned have been committed to a philosophy of treating customers’ businesses as their own: Providing a consistently high level of service by using the most suitable equipment and employing professionals with equally high standards and work ethics.

Today the company specialises in the temperature-controlled transport and storage of a full range of perishable products of every temperature variation including ambient, chilled and frozen.

Meritor MT23-165G pumpless drive axle.

With John’s sons Neil and Craig now at the helm, the company maintains an efficient and safe linehaul service primarily between the capital cities of Adelaide, Melbourne and Sydney.

John remains actively involved in the business and is often found behind the wheel of a truck, picking up or delivering a local load or performing a change-over.

One of Collins Transport’s valued employees is Carl Hamilton, National Workshop Manager based at the Adelaide head office, working alongside of Ryan Collins, whom has become a wealth of knowledge of the Meritor product.

Together they run a professional workshop with well suited technicians.

Carl has been in this role since 2020 and has extensive experience in similar roles with other large transport companies dating back more than 20 years.

His modus operandi, in synch with that of the company’s, is to get the absolute best performance, efficiency and longevity from every piece of equipment.

It’s for this reason that he’s been specifying Meritor MT23-165G pumpless drive axles in every new Kenworth the company has bought over the last 12 months or so. And he says this practice will continue for the foreseeable future.

Carl explains that the diffs are factory-filled by Kenworth with Castrol Dynadrive which is a long-drain synthetically fortified 80W-90 oil with 200,000km drain intervals.

Importantly, this eliminates the requirement for the standard 10,000km first drain of the diff oil.


“We have been using the MT23-165G for some time now and probably the biggest difference we have noticed between it and the Meritor RT46-160 carriers on our older trucks is much lower operating temperatures on linehaul B-double and B-triple work,” Carl states.

While he accepts that in theory the new pumpless carrier should provide a small fuel saving, he says this is very hard to quantify due to variable factors such as load and prevailing climatic conditions.

“On average our Kenworth prime movers do around 400,000km per annum, but I could not say that we have noticed any improvement in fuel efficiency to date,” he says.

On the topic of longevity of the new carriers, Carl says there has been one small hiccup, but only with one diff which tends to suggest it may be an isolated quality control issue.

“We utilise scheduled oil sampling for all oils in the trucks and this picked up high metal content in the oil of one diff carrier at 300,000km,” Carl says.

“Meritor was very proactive and quickly organised for a new unit to be installed under warranty. Upon tearing down the diff it was found to have excessive wear of the thrust washer on the pinion.

“We’re not sure at this stage whether or not it’s a one-off occurrence because the others haven’t done enough kilometres yet, but we are confident that Meritor can sort it out because the company has always done its utmost to look after us,” he says.

Scheduled maintenance work being performed on a Kenworth.

Oil sampling is a bit like a benchmark for the company as it provides an early warning system to help avert the catastrophic failures that can occur in components if an issue goes unaddressed explains Carl.

“We store all the results on file for each vehicle and if we discover anything out of the ordinary driveline wise, we pull it out and take a look,” he says.

“We are huge on preventative maintenance and huge on full utilisation so if we pick up a problem through oil sampling we bring the vehicle into the workshop, remove the suspect component and replace it with an identical item we have in stock to get it back on the road as soon as possible.”

The company holds around $1 million dollars-worth of spare parts in stock to ensure continuity and efficiency in the servicing of the fleet.

The workshop operates around the clock, with a lot of the work done between midnight and 6.00am.

“At those times we can’t source spare parts so we need to ensure we have whatever parts we might need in stock, and these are then replenished later in the day when the suppliers are open,” Carl says.

The company has a full-time crew of highly skilled mechanics that carry out the maintenance and repairs, including rebuilding the components such as gearboxes and diffs which are then put into stock, ready for the next time they are needed.

“This is a necessary strategy that enables the prime movers to average around 400,000km per annum, giving us the maximum utilisation required by the business,” Carl says, adding that the company has around 140 linehaul and a further 40 or so local units.

An important factor in the company’s performance, according to Carl, is the brand of prime mover which in the linehaul fleet is almost entirely Kenworth.

Most of the fleet comprises K200 cab overs, although there are still a number of K108s and K104Bs kicking on, some with over four million clicks on the clock.

The company also runs a handful of T909 and T610SAR conventional models.

In the local fleet, DAF – also part of the PACCAR portfolio along with Kenworth – dominates and Carl has good things to say about the Dutch marque that is now assembled at PACCAR’s Bayswater (Vic) manufacturing plant.

“We’ve been steadily increasing the number of DAFs in our local fleet over the past few years and we have them in a mix of eight-wheel rigids and prime movers,” he says. “The DAFs are proving to be excellent local trucks and in my estimation are an ideal truck for our short haul and regional operations.”

In wrapping up, Carl says he cannot stress enough the importance of strong relationships with key personnel at the various suppliers, including Meritor, that manufacture the components that keep the wheels turning in the Collins Transport operations.

“Meritor as a company is excellent to deal with and our Territory Manager, Renzo Barone, has been super helpful, particularly with any issues we’ve encountered like the previously mentioned premature thrust washer wear in one of the new carriers,” Carl says.

“I also revealed earlier that there are two mottos that we live by in this business – preventative maintenance and maximum utilisation.

“With the aid of Meritor and our other valued equipment suppliers, we are able to keep both of these factors at peak levels to ensure the most efficient and profitable operation of Collins Transport.”

The Collins Transport workshop in Adelaide.