Transmission Diagnostic: Symptoms, Defect & Solution

Cars are complex machines which require well-versed engineers to monitor the production on large scale. The repair and maintenance of all-wheeled drive also require best of mechanics to troubleshoot and fix the problem.

The first diagnostic run by mechanics is on car transmission system. It is the most integral and interconnected system in a vehicle. It provides engine power from piston through transmission component to driveshaft. A typical transmission consists of gear box, pump, valves, torque convertor, transmission fluid, clutches and band. The vulnerability caused by transmission error can get severe if left untreated.

Just like a doctor, a mechanic may want to know the details of your car’s first sign of trouble. So, in a curious way, one must always note down the symptoms signaled before a problem. The car may shake, jump or come to halt at acceleration. It may bring out screeching sound or whistle during the run. A visible leak of transmission fluid or darkening of fluid may be noted. In case, a burning or pungent odor is observed, it is due to overheating or adulteration of transmission fluid.

What are the possible transmission default and its solution?

  • Transmission Fluid — Leakage, Viscous, Contaminated

Transmission fluid is a working fluid that is responsible for friction-less working of shaft and gear box. It also takes away torque-induced excessive heat. In the process, the fluid may get contaminated by pollutants or become viscous. This may cause over-heating resulting in burning smell coming out of the car. A leakage is easiest defect to diagnose. It is necessary to run a check on tank if the fluid level is low for any leakages if not visible.

SOLUTION: The mechanic may flush out the old fluid and refuel it with new. If leakage is confirmed, change of transfer case services may be provided.

  • Clutch Failure — Dragging, Not shifting gear

A clutch failure could make the driving hectic as it makes shifting from one gear to another difficult or all most impossible. It happens when the clutch disk denies taking action from the gear stick when clutch plate is pressed as it doesn’t disengage the flywheel. This could be due to driver’s constant acceleration while pressing clutch plate or long-term use of clutch.

SOLUTION: Depending upon the problem, mechanic might just change the clutch plate. Else, check for defects in dog teeth, collar or sychros.

  • Gear Synchronizer

In manual transmission, the driver has to press the clutch plate and set the engine free from transmission before shifting the gear. Meanwhile, the synchronizer keeps the spin at same speed while shifting from the current gear to the changed gear position. This makes the experience of shifting gear smooth and free from jerks.

SOLUTION: Synchros or Synchronizer if gets defected, needs to be changed.

Vehicles are life-changing machines but must be maintained as they deal with energy generation and retardation. They possess harming potentials; hence, only experts of the field should handle the problems. Always, take your car to consult a professional mechanic.

Originally published at on May 17, 2017.