Several current and late-model vehicles use cables to connect the shift lever to the transmission. Vehicles with automatic transmission typically have one transmission cable, while vehicles equipped with manual transmissions typically have two shift cables. The concept of what the gear lever cable does is the same regardless of the type of transmission your vehicle is equipped with; the symptoms, on the other hand, are completely different.
What the shift cable does
Automatic transmissions have a single shift lever that is linked to the manual valve on the transmission valve body. This lever is pushed and pulled in a single plane in several different positions as you move the gear lever within your vehicle. Manual transmissions have two shift levers: one for vertical movement and one for horizontal movement of the shift lever assembly in the transmission. The horizontal lever is pushed or pulled by a cable, moving along a single plane with three positions. The second lever, or vertical, generally moves the shift lever assembly in the transmission up and down. When you move the shift lever towards the front or rear of the vehicle, the shift lever cable moves the lever horizontally. Moving the shift lever left or right pushes or pulls the other cable, moving the shift lever assembly up and down. If you have a six-speed manual transmission, your vehicle may have a third shift cable that moves a lock lever. This cable is only used when you press a button or push down on the gear lever to engage reverse.
Why the cables fail
The most common reason for a shift cable failure is stretching. It’s more common on manual transmission vehicles because you move the gear stick more often; You don’t just set it and forget it like you do with an automatic transmission. Cables have also been known to break or, in some circumstances, bend, preventing them from moving the transmission shift lever to the correct position for the selected gear. Overdriving any type of transmission or hitting the gears on a manual transmission will cause accelerated wear on a shift cable.
Symptoms of a bad automatic transmission shift cable
If your vehicle’s gear position indicator is not electronic, you will notice that the pointer does not line up correctly with the gear you are actually in. As the cable stretches over the life of your vehicle, you may notice that the needle will point in reverse while parked, or go between reverse and neutral when in reverse. Sometimes you will have a little play in the gear stick, even though the transmission is already in gear. When the cable is stretched too far, you may not be able to park properly or manually select first gear. When the cable is stretched this far, it can also prevent you from turning the ignition off completely or removing the ignition key. Because all automatic transmissions are equipped with a neutral park safety switch, a stretched cable can prevent the engine from starting in park and neutral or allow it to start spinning while the transmission is in any other gear.
If your car doesn’t seem to want to put a gear at all, it may not be a faulty transmission, it could just be a broken gear stick cable. If the cable is broken, you will be able to move the shifter to any position, but the transmission will stay in the same gear. This can get you stuck in gear or even parking depending on when the cable broke. There is a quick test you can take. If the vehicle does not go into gear, shift the transmission to neutral and try to push the vehicle a couple of feet. If you can only move the vehicle, but its indicator says neutral, the cable is probably broken.
Some auto shift cables can be adjusted. If the cable is out of adjustment, you will experience the same symptoms as if it were stretched out.
If the transmission is stuck in any gear except neutral or park, and is equipped with a neutral park safety switch on the inside shift lever assembly, the vehicle will throw forward or backward if you attempt to start the engine .
Parking with a broken auto gear cable
When a gear lever cable breaks, you’re very lucky if it breaks …