Used Car Buying - Drivetrain

Drivetrain failures to watch for when buying a used car

Common drivetrain failures for a used car would include wheel bearings which are old, corroded or squeaky. When you test drive the vehicle you should not hear any squeaking that relates to the spinning of the tires. If a wheel bearing is wearing out it will squeak somewhat regularly and even more so when cornering the vehicle.





Wheel bearings which are completely worn out will grind and growl more than squeak and some associated vibrations may be felt in the steering wheel while driving. wheel bearings are an integral steering component and must be replaced when first signs of wear develop. If a wheel bearing is allowed to progress until completely worn out this is a strong indication that the car has not been maintained properly.

How to inspect CV joints in front wheel drive cars

In front wheel drive cars you will find steering parts called CV joints. CV stands for constant velocity but essentially this is a steering component and one that is prone to wearing out. Underneath the front wheels you will find a conical shaped rubber boot, which often could have accordion like wrinkles in it, which serves to protect the mechanical joint underneath it from road dust.


This dust boot is sealed and packed with grease to protect the moving mechanical parts that make up the CV joint. It is very common to find CV joint boots which have become damaged or worn out, and where the packed grease has leaked out.





Our expert mechanic advises us that once a CV joint boot has ruptured and leaked out the CV joint will need to be replaced - it is now simply a matter of time.


The boot itself is a cheap rubber part that you can replace if the cars original boot becomes damaged. Unfortunately replacing the boot will not protect the CV joint once it has been exposed to dirt and debris. Even if you replace the boot and repack the grease, in many cases the damage has already been done and it is a matter of time before dirt and debris degrade the condition of the CV joint itself.


The CV joint is a much more expensive repair as the replacement part requires replacement of the entire CV joint shaft. Both sides of the car have a CV joint and generally one is more expensive to repair than the other due to the length of the CV joint shaft.


The following section deals with one of the more common problems encountered when buying a used car - the electrical system.