One of the most annoying things that can happen to a vehicle is when it jerks shifting gears. There are a few things that can cause the problem. They aren’t necessarily related to the transmission itself. One of the side effects of a car jerking is motor mount or crossmember damage. You’ll want to fix it sooner rather than later.
Automatic Transmission Jerking When Shifting Causes
Transmission Fluid Level– A great place to start looking is the transmission fluid. Transmission fluid that is at the wrong fill level will cause the transmission to behave differently. If the fluid gets too low, than the car won’t move at all. See: Low Transmission Fluid Signs
Bad Fluid– If the transmission fluid has worn out, the transmission will behave differently. It does more than just lubricating the transmission parts.
Transmission fluid is also responsible for the temperature control. If the transmission overheated for any reason, that can be enough to necessitate a change. The color of the fluid can tell you a lot. For more check out: What Color is Transmission Fluid?
If the transmission fluid starts to lose some of its lubrication properties, it can cause rougher shifts to happen. This is due to the clutch packs jerking when engaging between shifts.
Outside Air Temperature– The temperature outside, especially when it is cold can change the characteristics of the transmission shifts. This should work itself out when the vehicle warms up. Be aware that it takes a longer amount of time for an automatic transmission to warm up than the engine itself.
Shift Solenoids– Shift solenoids control the engagement of gears. When they go bad they cause all sorts of problems. If one of them has a delay in engagement, it can the transmission to buck and jerk until the solenoid can engage all of the way.
Clutch Packs– It’s more likely that when a clutch pack wears out it will slip, and not grab and jerk. But, if they have been exposed to excessive heat in them it can cause them to wear unevenly. When this is the case they can cause the vehicle to chatter and jerk in-between shifts.
Final Thoughts on a Jerking Between Shifts
The ideas listed above apply to transmission related issues. Keep in mind though that shifting causes a change in RPM. When a vehicle has ignition problems they typically manifest themselves at lower RPM under heavier loads.
It may be worth your time to make sure that you don’t have an ignition problem, such as a bad coil pack before servicing your transmission. If you are convinced your transmission is at fault, get it in before it fails you entirely. Good luck!