Over 40 Years of Expertise
What Gearbox & Transmission Repair Involves
Transmission repair covers the full range of work needed to get power moving correctly from your engine to your wheels. Depending on what our diagnostics uncover, this can mean a minor fix, a full internal rebuild, or a complete transmission replacement. We work across the full spread of transmission types on New Zealand roads, old and new:
- Automatic transmissions. Valve body issues, torque converter faults, band and clutch pack wear, and fluid-related failures are all common as automatics rack up the kilometres. We diagnose and repair or rebuild to get smooth, reliable shifting back.
- Manual gearboxes. Clutch-related faults, worn synchros, notchy or difficult gear selection, and bearing wear are our bread and butter. We repair and rebuild manual boxes across passenger vehicles, utes, and commercial fleets.
- CVT (Continuously Variable Transmission). CVTs use a belt or chain and pulley system rather than fixed gears, which makes them smooth to drive but sensitive to fluid condition and prone to specific belt, pulley, and torque converter faults. CVTs need the correct fluid type and specialised diagnostic knowledge, which is where our experience counts.
- DSG (Direct Shift Gearbox) transmissions, common in newer European vehicles, which combine the fast shifting of an automatic with the mechanical layout of a manual and require specialised knowledge to service correctly. We work on mechatronic units, dual-clutch packs, and the electronic controls specific to DSG systems.
- Classic car and hot rod transmissions. Older and custom-built vehicles often run gearboxes that are no longer in mainstream production, and parts availability and know-how matter as much as tools. Our team has the experience to diagnose, rebuild, and source parts for classic and hot rod transmissions, keeping heritage vehicles on the road without compromising on originality where it counts.
- Electric and hybrid vehicle transmissions. EVs and hybrids use simplified, often single-speed reduction gear transmissions, or in the case of hybrids, more complex power-split systems working alongside the internal combustion engine. These require a different diagnostic approach and specific technical knowledge of how the electric drive and transmission components interact. Our team keeps pace with this technology so EV and hybrid owners aren't left without specialist options.
Every job starts with electronic diagnostics to identify exactly what's wrong before any parts come apart. This means you're not paying to replace components that don't need replacing, and it means we can give you an accurate picture of the work required from the outset, whatever the transmission type.
What's Included
A typical transmission repair at Marshall Transmissions & Automotive includes:
- Full diagnostic scan using dealer-level electronic equipment to read fault codes and pinpoint the issue.
- Inspection of internal components, including clutch packs, bands, gears, bearings, and seals, to assess wear and damage.
- Fluid and filter assessment, since old, contaminated, or incorrect transmission fluid is one of the most common causes of premature wear.
- Repair or rebuild of the affected components, using quality parts suited to your make and model.
- Full replacement, when a transmission is too far gone to repair economically, sourced and fitted to the correct specification for your vehicle.
- Road testing after any work is completed, to confirm smooth shifting and correct operation before your vehicle is handed back.
Signs You Need Transmission Repair
Transmission problems rarely appear out of nowhere.
Watch for:
- Slipping gears, where the engine revs but the vehicle doesn't accelerate as expected.
- Delayed or hard shifting, particularly a noticeable clunk or hesitation when changing gears.
- Fluid leaks, often a reddish or brownish fluid pooling under the vehicle.
- Burning smell, which usually points to overheating transmission fluid.
- Unusual noises, including whining, humming, or clunking that changes with gear selection or speed.
- Warning lights, particularly a check engine light triggered by a transmission-related fault code.
- Difficulty selecting gears, common in manuals with a worn clutch or failing synchros, and in DSG vehicles experiencing mechatronic unit issues.
If you notice any of these, the sooner it's checked, the more likely it is to be a straightforward repair rather than a full rebuild or replacement.
Why It Matters
A transmission fault that's ignored doesn't stay small. Metal shavings from worn components circulate through the fluid and damage other parts. A slipping clutch pack overheats and accelerates its own failure. What starts as an intermittent shudder can become a transmission that won't engage at all, usually at the worst possible time.
There's also a safety element. A gearbox that hesitates or drops out of gear unexpectedly, particularly at speed or when overtaking, puts you and other road users at risk. Beyond safety, transmission repairs are among the more expensive jobs a vehicle owner will face, so catching a problem early genuinely protects your wallet as well as your car.
What to Expect From Our Team
When you bring your vehicle to Marshall Transmissions & Automotive, we start with a proper diagnosis rather than guesswork. We'll explain what our scan has found in plain terms, talk you through the repair options available, and give you a clear cost before any work begins.
Our team has hands-on experience across manual, automatic, and DSG transmissions, so whether you're driving a well-used ute or a late-model European car, we've got the equipment and expertise to handle it. We aim to get your vehicle back on the road running smoothly, with the work backed by our workmanship and a clear explanation of what was done and why.
