The drive unit — motor, reduction gear, and inverter — is the single most expensive mechanical assembly on your EV. nexdrive certified technicians service it with OEM-spec fluids, filters, and diagnostic tools built for the way each manufacturer actually engineers it.
An EV drive unit packages the electric motor, a single-speed reduction gear, and (on most modern EVs) the inverter into one sealed housing — some vehicles have a second drive unit for the rear or front axle on dual-motor AWD models. There's no engine oil, spark plugs, or multi-speed transmission, but the reduction gear still runs in a bath of gear oil that lubricates the gearset and carries heat away from the motor.
"Sealed" doesn't mean "forever." Heat cycling from normal driving and slow moisture ingress past the housing seals both degrade that fluid over years, even with zero leaks. Degraded fluid loses lubricity and can start carrying microscopic metal particles from normal gear wear — which then accelerates further wear if it's never changed.
Every manufacturer treats this differently — some publish a fluid change interval, some call it a lifetime fill, and Tesla is currently the only major brand building an actual filter into the drive unit. We service each vehicle to its actual specification, using OEM-spec fluid and, where applicable, the correct filter — not a generic substitute.
Book a Drive Unit InspectionA change in gear whine pitch or a new grinding note often points to worn or contaminated gear oil
A seal or housing leak needs attention before the fluid level drops enough to starve the gearset
Can indicate a motor, inverter, or gearset fault that a diagnostic scan can catch early
Often a worn drive unit mount rather than the motor itself — an easy, inexpensive fix if caught early
Modern EVs monitor motor and inverter health directly — a warning means it's time for a scan
OEM-spec reduction gear fluid service to manufacturer interval. For Tesla drive units built with a filter (2021 model year onward), we replace the correct filter alongside the fluid — Tesla is currently the only major brand using one.
Full scan of motor and inverter fault codes, performance data, and torque output to catch developing issues before they cause a breakdown.
Worn motor mounts cause vibration and clunks that are often mistaken for a motor fault. We inspect and replace mounts to restore a smooth, quiet drive.
We check drained fluid for metal particulate and discoloration — early signs of gear or bearing wear — and inspect the gearset itself when indicated.
Drive unit seals can weep over time. We identify the source of any leak and repair it before fluid loss starves the gearset of lubrication.
A complete visual and diagnostic check of the drive unit — mounts, seals, fluid condition, and motor/inverter fault history — included with every EV service visit.
Every manufacturer specifies drive unit service a little differently. We follow each brand's actual fluid, filter, and interval requirements rather than a generic schedule.
The drive unit is one of the most expensive components on any EV — often a bigger repair bill than the battery itself if it fails. We use manufacturer-specified gear fluid for every brand we service, and for Tesla, the correct OEM drive unit filter rather than a generic substitute.
Wrong-viscosity or off-spec fluid can accelerate wear on the exact components it's supposed to protect. On a part this expensive to replace, the fluid and filter aren't the place to save a few dollars — it's the cheapest insurance you can buy for your drive unit.