Differential & Axle Overhaul (Hub-Reduction & Single-Reduction)

Cora Amyra
4 days ago
3 min read

Axle & Differential Overhaul for European Heavy Vehicles

The gearbox can only do its job if the drive axles and differentials are healthy. For heavy European applications – city buses, tippers, mixers, prime movers and mining support trucks – operators in Singapore commonly use hub-reduction or heavy single-reduction axles from Scania, Volvo, MAN and others

Scantruck provides complete overhaul services for:

Tandem drive axles on 6×4 and 8×4 trucks
Rear axles on buses and coaches
Hub-reduction axles in construction and mining support vehicles

Scania R660 / RB662 Hub-Reduction Axles

A common configuration in modern Scania trucks is the RB662 + R660 tandem gear, a tandem-driven single-reduction or hub-reduction assembly rated for gross vehicle and train weights up to 80 tonnes, with gear ratios from 2.92 to 4.88 depending on spec.

Key characteristics:

High-capacity differential unit (R660) with selectable diff-lock, designed for long-haul and construction duties.
Optional hub reduction on some variants to lower torque in the axle shafts while increasing ground clearance and durability in heavy-haul applications.

Typical failure points:

Pitting or spalling on crown wheel and pinion from contamination or incorrect preload.
Worn differential locks and dog clutches causing incomplete engagement and sudden failures under load.
Bearing failures in hub-reduction planetary sets due to lubricant degradation or overloading.

Scantruck’s overhaul programme includes:

Full strip-down of the differential carrier (e.g. R660) and hub units.
Gear tooth contact pattern checks, backlash and preload set-up to factory specifications.
Replacement of bearings, seals and locking devices using OE-equivalent parts.
Inspection of axle housings for fatigue or misalignment, which can otherwise destroy a freshly overhauled diff.

Volvo, MAN and Other European Axles

While model codes vary (e.g. different Volvo hub-reduction and MAN tandem axles), the technical themes are similar:

Single reduction vs hub reduction – balancing efficiency for highway work versus durability and ground clearance for construction/mining.
Planetary hub sets – correct bearing preloads and gear backlash are critical; cheap partial repairs often ignore internal wear.
Diff-lock and cross-lock systems – actuators and dog clutches must engage cleanly; rounded teeth and poor air supply cause failures.

Scantruck’s axle work typically accompanies engine and gearbox overhauls so that the entire driveline (engine–clutch–gearbox–prop-shaft–axles) is brought back to a known condition.

Why Overhaul Axles With an Engine/Gearbox Job?

For a European CV operator, there are strong technical reasons to synchronise these jobs:

Matched ratios – when swapping differentials or final drive ratios (e.g. moving from a 4.88 to 3.27 R660), gearbox and engine calibration must be checked to maintain performance and fuel consumption.
Shared contamination – when a differential or hub fails, metallic debris frequently travels through the oil into the brakes and bearings; similarly, failing U-joints can shock-load both gearbox and axle.
Downtime optimisation – most operators prefer a single planned downtime window where engine, gearbox and axles are all inspected, overhauled where necessary, and returned with a unified warranty.

How Scantruck Positions Itself in the Axle Overhaul Market

European only, by design – We focus on Scania, Volvo, Mercedes-Benz, MAN and DAF driveline packages, which allows us to invest in the correct tools, data and parts for these families.
Integration with our gearbox and engine work – We routinely see vehicles where a gearbox failure was caused by a dragging brake or a failing hub-reduction; treating the driveline as a system is what reduces repeat failures.
Support for demanding sectors – Public bus fleets, construction and mining support trucks, and logistics operators who need predictable uptime and clear documentation.

If you’re planning a major engine or gearbox overhaul on a European truck or bus in Singapore, talk to Scantruck about including a differential and axle inspection at the same time. It’s often the most cost-effective way to secure the entire driveline.