How Can I Tell If My Transmission Is Slipping?

Transmission work is among the most expensive auto-repair jobs. Because a transmission repair can cost thousands of dollars, many drivers are reluctant to take their car in when signs of trouble first appear. Unfortunately, this delay only results in higher repair bills for most drivers. Because transmissions become progressively more damaged, they should be taken to a mechanic at the first signs of slipping. With some basic automotive knowledge, you'll find the symptoms of a slipping transmission easy to identify.

Car Hesitates Before Accelerating

  • When working properly, your car's automatic transmission will shift into first gear when the vehicle is stopped. This ensures that the vehicle is ready to move quickly. As the transmission begins to fail, though, it may not properly shift into first gear when the car is idling. When you press the accelerator, the unengaged transmission must attempt to shift into gear, causing a slight delay before the car starts moving. You may also notice high engine revolutions or a high reading on the tachometer before the transmission engages, and your car may lurch or squeal its tires when the transmission finally drops into gear.

Hesitation Between Gears

  • Even if the automatic transmission does not slip when you accelerate from a stop, other symptoms may appear as the car shifts through its higher gears. Under normal conditions, an automatic transmission should shift smoothly between each gear, sometimes so smoothly that the shift is almost indiscernible as the vehicle accelerates. A slipping transmission may shift more slowly while changing gears, however, causing the vehicle to briefly pause during its acceleration. When the shift finally occurs, you may feel the transmission slowly settle into gear as the vehicle gradually regains acceleration. During the shift, too, you may also notice that the engine revolutions increase or tachometer readings edge higher; the revolutions and tachometer readings should return to normal after the transmission shift is complete.

Higher Than Normal Engine Revolutions

  • Many drivers with slipping transmissions notice higher than normal engine revolutions under initial acceleration or between gears. In extreme cases, slipping transmissions may allow engine revolutions to edge higher even when the transmission is not actively shifting. Because slipping transmissions fail to fully engage as the damage advances, some of the engine's power may be wasted rather than effectively transferred to the car's drive shaft. If your car has a tachometer, you may notice that your engine is spinning at higher revolutions than previously required at the same speed. Some engines can be heard audibly revving higher. When these symptoms appear, visit a transmission repair shop immediately to avoid further damage or a complete transmission failure.