I use this trick when checking out a used car. Since you can not climb under a car and check how much material is left on the clutch disc, you can only guess the condition. Using the following tips you can get closer to an educated guess and hopefully make a good decision.
1. Operate the clutch and observe where the clutch grabs. It should grab about 2″ from the floor. The motion of the pedal should be smooth and even. Make sure you have the emergency brake on when doing any of these tests.
2. Listen for any chatter or squealing when operating the clutch. Is there a grinding noise when the clutch is depressed? This indicates a worn throwout bearing, and will require the transmission to be removed to replace it. You can assume if the throwout bearing is bad, the clutch is not in the best condition.
3. Put the car in 2nd or third gear and let the clutch out slowly. (make sure the car’s emergency brake is on, and you have your foot on the brake) Does the engine RPM decrease and almost stall? If it does, the clutch still has some life in it, and is doing it’s job. If the clutch slips, and the engine does not sound like it’s going to stall, there is a good chance the clutch needs to be replaced.
4. While on a road test, does the transmission shift smoothly? Is there any crunching when changing gears? A crunching noise when shifting usually indicated bad sychnonizers in the transmission, but can sometime just be the clutch cable being out of adjustment.
Keep these tips in mind the next time you are inspecting a used car, or trying to diagnose your own car. A manual transmission car can be a blast to drive, and offer better fuel economy, but presents unique issues when trying to evaluate it’s health.
More information on your Car’s driveline
While I know a lot about cars, I don't know a lot about YOUR CAR! If you are looking for vehicle specific instructions, an online repair manual is the ticket. I recommend Alldata or Mitchell1, but also have some tips to get a free repair manual which while not as complete, can work in a pinch.
Learn more with our Autoshop101 courses.
Posted: 6th February 2006 | Author: Kevin Schappell | Category: Drivetrain