A slipping transmission is a common problem, especially for older cars with automatic transmission. However, the problem may appear in new cars, and may affect manual transmissions too. The causes for this may vary, from very used transmission sprockets, to inadequate transmission fluid, low fluid pressure or other issues. Detecting a transmission slipping problem can be done in a matter of minutes.
Put your transmission in the parking position and start the engine.
Hold down the brake and put the shifter in the drive position. Almost instantly, the transmission should engage. If there is a delay of more than one or two seconds before the transmission engages, it may be slipping.
Release the brake and start driving around. Push the gas paddle slowly and pay attention when your car switches gears.
When the car switches to a superior gear, the RPM indicator should drop a bit, but should rise again once you step on the gas.
If the indicator does rise and you hear the engine accelerating but the speed of the car does not increase then that is the sign of a slipping transmission.
Put the shifter out of gear and start the engine.
Hold down the clutch and move the gear shifter into various gears.
Pay attention for a click-life feel when a shifter enters a gear. If there's no click or the shifter seems to just move loose, the transmission may be slipping.
Start driving around and, while moving, push the clutch all the way down, wait a bit for the car to slow down and slowly release the clutch. The car should smoothly gain some speed. If it suddenly shakes before accelerating, that may be a sign of a slipping transmission.
