About your transmission:

Think of the engine as the “heart” of your vehicle and the transmission as the “muscles.” While the engine generates the power, the transmission decides how to use that power effectively.

Transmissions Manage “Rotational Speed” (RPM)

Car engines have a limit on how fast they can spin (measured in Revolutions Per Minute, or RPM).

The transmission uses gear ratios to allow the engine to stay in a comfortable, safe RPM range (usually 1,500–3,000 RPM) while the wheels spin at widely varying speeds, from 0 to 100+ mph.

Trade Speed for Strength (Torque)

Engines produce power, but they don’t always produce the “leverage” needed to move a heavy object from a standstill.

Starting (Low Gears): To get a 4,000-lb car moving from a stop light, you need massive twisting force (torque), not speed. The transmission selects a “low gear” to multiply the engine’s force. This is like using a long lever to lift a heavy rock.

Cruising (High Gears): Once the car is moving on the highway, you don’t need as much force to keep it going; you need speed. The transmission shifts to “high gears” (overdrive), allowing the wheels to spin faster than the engine.

Disconnects the Power (Neutral & Idle)

Ideally, you want the engine to keep running even when the car is stopped (like at a red light).  

The transmission (via a torque converter in automatics or a clutch in manuals) allows the engine to spin independently of the wheels.

Without this ability to “slip” or disconnect, the engine would instantly stall and die the moment you hit the brakes to stop.

Transmission Problems?

Figuring out if your transmission needs attention usually comes down to using your senses—how the car feels, sounds, and looks.

The distinction between “service” (maintenance like a fluid change) and “repair” (fixing broken parts, rebuild or replacement) often depends on how early you catch these signs. If the driving experience changes negatively, the transmission is often the culprit.

Slipping: The engine revs up (RPMs go high), but the car doesn’t speed up accordingly. It feels like driving on ice or that the car has lost traction.

Rough Shifting: You feel a noticeable “clunk,” jerk, or shudder when the car changes gears, rather than a smooth transition.

Delayed Engagement: When you shift from “P” to “D,” there is a long pause (more than a second) before you feel the gear catch and the car is ready to move.

Transmission “Sound”

Transmissions are generally quiet; new noises are a major red flag.

Whining or Humming: A low whine that gets louder as you accelerate is a classic sign of transmission trouble (often low fluid or a worn pump).

Grinding: Metal-on-metal grinding usually indicates physical damage to gears. If you have a manual car, this often happens when you try to shift.

Clunking: Hearing a loud clunk when you are coasting or slowing down can indicate loose or worn internal parts.

“Look” Test (Fluid Inspection)

This is the most accurate way to tell if you need a simple service or a major repair.

Check the ground: Look for reddish puddles under your car. Transmission fluid is typically bright red. If it’s leaking, you need a repair to stop the leak, but the internal damage might be minimal if caught fast.

We check your transmission fluid during normal initial service testing.

Burning Smell: If you smell something acrid or like burning rubber, your transmission fluid might be overheating. Old, dirty fluid cannot cool the system down, leading to friction and heat.

We are experts in repairing Mercedes transmissions, so call us to get started on your car or SUV soon!

817-732-4888