Now, (with caution – safety first!), shift the transmission lever into neutral. Apply the parking brake. With the engine idling, press the clutch pedal all the way, hold it down, and listen for noises. Then release the pedal and listen for noises again. There should be no loud noises at either positions.
The next step is the test drive.
Try to drive the vehicle at different speeds in all gears, one by one. Every gear should shift smoothly and easily without any noises or jerks. While driving at the second or third gear, try to press down sharply on the accelerator pedal for an instance. The clutch should not slip.
If you feel any slipping (e.g. the engine rpm increases but the speed remains the same), the clutch most likely has to be replaced.
Try to drive with acceleration and deceleration – there should be no grinding, whining or humming noise under any condition. All the gears should shift easily and noiselessly.

Check the CV joints

Broken CV joint boot

A Constant Velocity joint or CV joint is an important component of the drive train. The CV joint is packed with grease and protected by the rubber or plastic boot. Most common problem with the CV joints is when the protective boot gets damaged. Once this happens, the grease comes out and the moisture and dirt come in, eventually causing the CV joint to fail due to lack of lubrication and corrosion. In worst case, the CV joint may disjoin causing the vehicle to stop running. You can check the condition of the CV joint boots visually. You can see them with the front wheel turned outside, looking down from the front of a car. None of them should be damaged. Look at the photos. The CV-joint boot in upper image is damaged, in the lower image it looks OK. If a boot is damaged, it has to be replaced as soon as possible. If continue driving with broken boot, the CV joint or a whole drive shaft will need to be replaced. While drive test, If you hear clicking or popping noise when turning, the CV joint is probably already defective.

One of the indications of a transmission problem is delayed engagement, when there is a long delay between the moment you shift the shifter into “D” (Drive) or “R” (Reverse) and the moment the transmission kicks in.
It’s easier to note delayed engagement after a car was sitting for a while: With the transmission in “P” (Park) start the engine, and wait until the engine rpm has reduced to normal level (650 – 850 rpm).
With your foot holding down the brake pedal, shift to the “D” (Drive) position. Almost immediately the transmission should engage – it feels like the car wants to creep forward. This should happen very smoothly, without a strong jerk or clunk.
Shift to “N” (Neutral), and the transmission should disengage. Now, still holding the brakes, shift to the “R” (Reverse) position. Again, the transmission kicks in almost immediately – you will feel the car wants to creep backward. This also should be very smooth, without a jerk or clunk.
Now, still holding the brake pedal down, try to shift from D to R and back. There should be no strong jerk or clunk.
If there is a notable long delay (more than 1 seconds) between the moment you shift and the moment the transmission kicks in, such a transmission might be either too worn or has some problem, avoid this car.
If you feel a strong jerk or clunk while shifting, the car may have a transmission problem, avoid such a car.

Now it’s time to test drive the car.
With the shifter in “D” (Drive) position drive gently, with smooth and gradual acceleration. Until the vehicle reaches a speed of 30-37 mph (50-60 km/h) or you should feel the gears shifting at least twice (from first to second, and from second to third gear).
All shifts should be done very smoothly, without jerks or slipping.
You should be able to feel when the transmission shifts by the slight change in the engine tone or change in engine rpm. If the transmission is extremely worn it may shift with quite a strong jerk, shudder or a delay (especially from first to second gear).
Driving at a speed of 25-30 mph (40-50 km/h) if you press down the accelerator pedal for a few seconds, you should feel downshifting to the lower gear, if the automatic transmission works properly.
The next step: check overdrive.
While driving at 60-70 km/h or 35-45 mph on a level road, without using the accelerator, switch overdrive ON. You should feel an upshifting to the next speed. Switch it to “OFF,” and you should feel a downshifting.
Another thing that may indicate the transmission problem is the slipping. When the transmission is excessively worn it may slip – which means you press the accelerator, the engine rpm increases but the speed remains the same.

If during the drive test you feel any problem such as transmission seems to slipping or shifts with a jerk or shudder or if the transmission got stuck in some gear, or has trouble shifting into a particular gear (for example, from second to third), avoid buying such a car.
Test-drive the car as long as possible. Often the transmission may work well when it’s cold but when it’s warmed up it starts giving troubles or visa versa. So, it’s better to spend more time checking the transmission than later fixing it endlessly. Normally there should be no shudder, no noises or any kind of strong jerks at any speed and at any engine temperatures while any shifting. If the salesperson tells you that the jerks or shudder or any other abnormal transmission behavior is “normal” for this car or it’s just because the car is cold or anything alike, don’t trust them. If the “check engine” and/or a flashing overdrive light comes on while driving, have the problem assessed with your mechanic before buying a car.