Car Gearbox Repairs

Almost all motorised vehicles have some form of gearbox, which is used to ensure that the engine power is transmitted to the driving wheels in the best and most efficient way.

Without a gearbox, a vehicle could only accelerate by increasing engine revs correspondingly, and at high road speeds that would mean dangerously high engine speeds. To ensure that a vehicle is able to drive efficiently in different situations, they are fitted with a gearbox.

A gearbox is a collection of meshed gears that have different ratios to allow for a variety of speeds. They are generally sealed units with an input from the engine – via the clutch – and an output to the driving wheels.   If treated properly gearbox is expected to last for the lifetime of a vehicle. Gearboxes usually run in thick oil and as long as this is changed at the correct intervals, and the whole units isn’t overstressed, it should perform without problem.

But sometimes gearboxes can go wrong and then they need to be investigated.

Common gearbox problems include

  • poor power transmission,
  • unexpected noises such as humming or grinding,
  • a loss of fluid, and
  • refusal to select a gear.
If any of these happen to your gearbox, it is recommended that you seek expert help from a trained mechanic. In that case, rather than attempt to fix the problem straight away – depending upon what it is – the mechanic is likely to source a refurbished gearbox as a replacement and then send yours away to be stripped and rebuilt for someone else to buy. To change a gearbox generally means the need for specialist equipment and the need to get the vehicle up on a hydraulic ramp, since most gearboxes are removed from the underside of the car. The fixing bolts are usually in difficult-to-reach areas so knowledge is paramount. An experienced mechanic will be able to remove and replace a gearbox within a few hours, and probably quicker.

Gearbox problems don’t all have to mean replacement and a noisy gearbox could mean something as simple as the need to replace or top up the oil, but it is always essential to get an expert view before doing any work yourself.