AMSOIL Tech Tips: Jerky Transmission

In this video, we show you what to do to fix a jerky transmission.

How to Fix a Jerky Transmission

If your transmission shifts erratically, jerks or hesitates, start with the easiest fix – your transmission fluid. The fluid level could be low, and low fluid can prevent the transmission from shifting properly. If that’s the problem, find out why the fluid is low and fix that issue. It could be a leaky seal or other mechanical defect. If you haven’t taken care of it, you haven’t fixed the real problem.

The Automatic Transmission Fluid (ATF) Could be Worn

It’s easy to overlook transmission maintenance, but your transmission fluid loses some of its frictional properties as it ages. When your vehicle’s computer tells the transmission to shift, hydraulic pressure provided by the fluid squeezes a series of plates together inside a clutch pack to connect the engine to the transmission and send power to the wheels. The fluid’s frictional properties play a vital role in ensuring the clutch plates bind together and properly shift the transmission. A fluid with degraded frictional properties can lead to jerky, inconsistent shifts. That means it’s time for a fluid change. How do you know the fluid is worn? Fluid analysis is really the only definitive way. But if it smells burned or looks dirty, it’s likely due for service. It’s best to do that before the fluid is completely worn out. Adaptive transmissions learn your driving habits and fluid characteristics to adjust shifts accordingly. As the fluid loses frictional properties, the computer compensates and adjusts. After a fluid change, the computer might think the fluid is still aged and it could cause some poor shift quality in the beginning.

Extreme Cold Can Cause Elongated Shifts

Cold, thick transmission fluid doesn’t flow readily at startup, especially in sub-zero weather. This can lead to elongated, sluggish shifts. In this case, switch to a synthetic ATF, like AMSOIL Signature Series Synthetic Automatic Transmission Fluid. It not only remains fluid in sub-zero cold for fast, crisp shifts, it maintains its frictional properties despite extreme heat and stress. To illustrate, look at the chart showing its frictional properties after more than 180,000 miles in a Las Vegas taxi. The frictional properties of used fluid (the light-blue line) are nearly identical to those of new fluid (the dark-blue line). This translates into excellent shift performance throughout the fluid’s service life. No ATF will fix a broken transmission, but using a high-quality synthetic fluid can help improve shift quality and maximize your transmission life.