The Transmission is the part that moves your car through the gears as it increases and decreases in speed. Transmissions generally come in two types Manual and Automatic. (We’ll leave semi-automatic to the real car buffs.)

Manual

Cars with manual transmissions (clutch/stick shift) usually cost less at purchase than automatic transmission. They also use less fuel, are less expensive to maintain, have better acceleration times, and make better use of the engine’s power (which can be especially helpful for smaller engine cars).  Makes you wonder why so many of us drive automatics, doesn’t it? The downside of manuals is that they require more effort to learn, more work to drive and can be downright maddening in stop and go traffic.

Automatic

Many drivers who want to be able to drink coffee on the way to work or do other multi-tasking couldn’t live without the freedom that the automatic provides since the right hand and left foot are free during driving. The manual requires the left foot to press the clutch and right hand to operate the gear shift. The automatic also scores a higher when compared to an improperly driven manual that can place undue stress on the engine and drive train.

Recognizing problems

Typical symptoms of transmission problems are:

• Leaking Fluid: Park your car in a clear, clean area for 24 hours. Then move the car and check for any evidence of liquid: drips or puddles. Red fluid is typically transmission fluid and may mean that you have a leak. Transmission fluid cools and lubricates the parts as they move. Low fluid can cause the trans to overheat and/or parts to wear down.  (NOTE: Green may be antifreeze very poisonous to pets and children, and black fluid is usually motor oil.) 
• Check Engine Light:  The check engine light tells you that the car’s internal computer detects a problem in one of the operating systems. It could be the transmission, or it could be the engine, or exhaust, etc. Better safe than sorry on this one. Get it in to a professional with the proper diagnostic equipment. 
• Something feels wrong: Grinding and shaking as you increase or decrease speed or shift gears can be a symptom of a serious transmission problem.  
• Makes funny sounds:   A transmission that is operating properly will not make noises. If you hear whining or humming, it’s a problem. Get it checked out. Note that the noises may only happen intermittently at first but will happen more and more frequently over time. 
• Won’t go into gear: When an automatic transmission hesitates or has issues engaging "Park" or "Drive" instead of shifting quickly into gear there's likely an issue with the transmission.