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Quick answer: Six 30-ton customized steel track undercarriages were delivered for a rotary drilling rig OEM in Saudi Arabia, using a sealed sprocket, pre-lubricated bushings and a constant-pressure hydraulic tensioner. Field results over 12 months: drive sprocket bearing life more than doubled and tension adjustments fell by over 90 percent.
Between 2024 and 2025, a rotary drilling rig OEM based in the Gulf approached MAGEON with a problem that is common in that region and uncommon anywhere else: their existing chassis supplier could meet the specification on paper, but the machines were consistently failing in service, and the failures were concentrated in the drive unit and the track chain.
The customer's position
The OEM builds rotary drilling rigs for water well drilling and mineral exploration across the Middle East, North Africa and Central Asia. They were experiencing three related failures on machines operating in desert and coastal environments:
- Drive sprocket bearing failures at 2,000 to 3,500 operating hours, consistently with sand and grit ingress
- Premature corrosion of the track chain pin and bushing interfaces, with the bushing bores measurably oval within a single season
- Repeated track tension loss requiring adjustment roughly every 40 operating hours
Critically, the customer was not able to change the machine design. Their customers bought the machine on the basis of an existing specification, and the machine had to keep working with the same chassis geometry. The problem had to be solved within a fixed envelope.
What the failure analysis showed
We reviewed failure records from three machines over an 18-month period, plus teardown reports from two returned chassis. The findings were consistent and unsurprising once quantified:
On the drive unit: the sprocket used an open bearing arrangement with an external labyrinth seal only. In a sand environment, the seal path was the weak link. We calculated the ingress rate required to produce the observed bearing contamination, and it matched the observed particle concentration in the working environment within a reasonable margin.
On the track chain: the bushings were a plain pressed-fit design with a single grease fitting. The pin and bushing interface is a sliding contact operating in a hostile environment. Without a seal, grit and moisture enter the sliding zone, and the bushing bore wears oval. Once oval, the pin takes a non-uniform load, the joint works loose, and the tensioner loses its authority.
On the tensioner: the spring type selected had a characteristic load-versus-deflection curve that dropped sharply as the track was extended. In a high-dust environment the track length grew faster than in a clean one, and the tension fell off a cliff as a result.
The solution
We proposed a revised chassis configuration within the existing envelope, keeping the machine's mounting interface and overall dimensions unchanged.
| Item | Original specification | Revised specification |
|---|---|---|
| Drive sprocket | Open bearing, single labyrinth seal | Sealed and factory-lubricated bearing arrangement, double labyrinth plus face seal, IP6X rated |
| Track chain | Plain bushing, single grease nipple | Sealed and pre-lubricated bushings, sealed pin and bushing interfaces, 3,000-hour re-lubrication interval |
| Tensioner | Spring type, progressive characteristic | Hydraulic tensioner with constant-pressure characteristic across the full stroke, plus integrated wear indicator |
| Seal protection | None | Additional labyrinth protection and sealed roller bearings on the idler and track roller trains |
| Track chain material | Standard alloy | Upgraded pin and bushing alloy with improved corrosion resistance, retained elastomer seal |
The critical engineering point
The most important decision was the tensioner, and it is worth explaining why, because it was not the most obvious choice.
A spring tensioner with a progressive characteristic has a natural equilibrium: as the track stretches, the spring force drops, and the track lengthens further, which drops the force again. The system is stable, but its equilibrium position is highly sensitive to conditions. A hydraulic tensioner holds a near-constant pressure regardless of chain length, so the track is always held at the same preload whether it is new or worn.
We also added a simple mechanical wear indicator to the tensioner body, so the service technician can check chain elongation visually rather than measuring every time. On a fleet spread across remote job sites, that is a meaningful reduction in inspection time and, more importantly, it means the tension is never left to chance between scheduled visits.
Results after 12 months of field operation
MAGEON supplied six chassis in the first production run. The customer's field data at twelve months, compared with the previous supplier's data on the same machine model, showed:
| Metric | Previous supplier | MAGEON chassis | Change |
|---|---|---|---|
| Drive sprocket bearing life | 2,000–3,500 hours | Over 6,000 hours | At least doubled |
| Track tension adjustments required | Every 40 hours | Every 500 hours | Over 90% reduction |
| Corrosion-related chain replacement | Within 1 season | None reported | Eliminated |
| Unplanned undercarriage downtime | Baseline | Down 70% | Significant |
Two of the six chassis completed a full 6,000-hour drilling campaign in a single abrasive formation without a single undercarriage-related failure, which the customer's own maintenance manager described as the first time in a decade that had happened with a rotary drilling rig in this region.
What the customer took away
From the customer's perspective the value was not the individual components. It was that the failures had been treated as environmental bad luck for years, and the question had never been systematically asked: which of these components are actually exposed, and by how much?
Once the exposure was quantified, the specification changes were straightforward and the cost impact was well below the value of the downtime avoided.
MAGEON's approach to this class of problem
Every project like this starts the same way: with the customer's failure data rather than with our catalogue. We ask for the failure history, the environment, and the maintenance records before we propose anything, because the correct specification for a chassis operating in a desert, on a coastal site, and in a temperate quarry are three different specifications — even when the machine is nominally the same.
If your fleet has an undercarriage problem that keeps recurring, the analysis is usually available, and it is usually worth doing. MAGEON's engineering team can work from your failure records and operating environment to identify which components are actually exposed and by how much.
MAGEON product lines and how they map to this topic
The engineering principles in this article apply across the full MAGEON product range. Each custom undercarriage order starts from one of four chassis families, and the selection logic above determines which one fits your machine.
| MAGEON product line | Typical tonnage | Best suited to |
|---|---|---|
| Customized steel track chassis | 3-60 T | Quarry, mining, crushing, demolition, heavy lifting and drilling rigs, where abrasive rock and impact loading drive the wear pattern |
| Customized rubber track chassis | 0.5-30 T | Urban construction, utility trenching, landscaping, agriculture and any finished-surface work where noise, surface protection and low ground pressure matter |
| Customized steel track undercarriage | 5-120 T | Continuous-duty mining and screening plant, large crawler cranes and heavy equipment carriers running extended shifts in abrasive conditions |
| Customized rubber track undercarriage | 1-20 T | Compact and mini excavators, tracked dumpers, harvesters and municipal plant, where a custom undercarriage is specified to meet ground pressure and noise requirements on the same machine |
Whether you are specifying a custom undercarriage from first principles, comparing a customized steel track chassis against a customized rubber track chassis, or reviewing the service life of a customized steel track undercarriage in abrasive service, MAGEON can size, engineer and support the build. Every crawler undercarriage project begins with your machine's weight distribution, working conditions and interface drawing, and the quotation is backed by a written calculation. Contact our engineering team with your host model, working conditions and mounting interface, and we will respond with a configuration recommendation within one working day.