Worn motor and/or tranny mount.
A clunking noise, when you put your car into gear, is most likely caused by a bad u-joint. A problem in the transmission can also cause the noise.
The engine also jumps when changing to Neutral and Drive. Should I have transmission fluid change? A/C was not on.
Mazda Proteges are known for their sway bar links to go bad around 80,000. They make a terrible clunking noise, but if intact (in most cases) the car is still safe to drive.
check the u-joints in the drive shaft first
ball joint, sway bar links tie rods have it checked out
chiken
probably your rearend
tie rod
You need struts
Bad shocks
A car that is in good running condition should not make a clunking noise. If a person pushes the gas and brake pedal at the same time causing a car to make a clunking noise, that is an indication of stain on the motor.
If there is a clunking noise on a 1991 Firebird Formula 5.0 when going below 30 mph, and the clunking noise does not happen when the clutch is depressed, it is probably a problem with the flywheel. The flywheel moves freely when the clutch is depressed. When the clutch is not depressed, it could be that something is rubbing on the flywheel, like the clutch plate.