Reasons Why Transmission Won't Shift Into Gear - Service Information at Capitol Chevrolet

The transmission is a mystery to many, and for good reason. It's a complex part of your vehicle made from many components, and it usually requires minimal interaction. You'll probably think about it much more if you drive a vehicle with a manual transmission, but it can become second nature so quickly that you may not pay it much mind. That is, until it doesn't work. There are many reasons a transmission may not shift into gear, and we've listed five common ones on this page. We'll start by taking a look at an issue that can affect both manual and automatic transmissions before going into more depth on common problems for both kinds.

Close-up of a gear shift knob

1. Degraded Transmission Fluid

Transmission fluid is vital to the proper functioning of your transmission, whether you drive an automatic or a manual. The fluid lubricates the moving parts inside the transmission, keeping them from producing excessive friction. Over time, this fluid can become degraded and contaminated. If contaminated fluid stays in your transmission for too long, it can make it much harder to shift. In addition, bad or expired fluid can damage your transmission, so it's best to have it inspected and dealt with immediately.

Worn clutch disc

2. Faulty Clutch Master Cylinder (Manual Transmission)

If you're driving a modern car with a manual transmission, it probably has a clutch master cylinder and a clutch slave cylinder. They're part of a sophisticated hydraulic system responsible for operating the clutch assembly. Just like your vehicle's hydraulic brake system, the fluid is key for the clutch to work properly. Any air or water in this system can cause problems, which is why it's important to keep up with recommended maintenance that includes the replacement of this hydraulic fluid.

3. Worn Clutch (Manual Transmission)

Though the clutch is a long-lasting part, it still gets worn over after time. A worn clutch can quickly result in an inability to change gears. Though a clutch replacement is a common maintenance procedure for manual transmissions, there are some steps you can take to avoid wearing it down prematurely. Don't ride the clutch, put your car in neutral when you stop for more than a second or so, and try to be gentle on the clutch when passing that cellphone drive who's going 15 under the speed limit.

Torque converter cutaway

4. Bad Torque Converter (Automatic Transmission)

Earlier, we mentioned that the clutch master cylinder engages and disengages the transmission from the engine in vehicles with manual transmissions. The torque converter serves the same purpose in an automatic transmission. In general, the torque converter includes components like a pump, a stator, and a turbine. Any one of these could become faulty, which can cause slipping when your transmission shifts gears. It can also keep the transmission from successfully shifting at all.

5. Damaged Shift Interlock Solenoid (Automatic Transmission)

Vehicles with automatic transmissions usually include a shift lock feature that keeps you from accidentally shifting out of Park when your vehicle is parked. You've probably noticed this already: you can't move into Reverse or Neutral unless you first step on the brakes. But if this solenoid is damaged, it may not recognize that you're stepping on the brakes. As such, you may be unable to shift out of Park at any time. This is a repair that is typically quick and affordable at our authorized Chevrolet service center in Salem, OR.