What Causes Hard Shifting in an Automatic Transmission?

by Jen DavisUpdated August 08, 2023
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Transmission problems are one of the most serious and expensive vehicle issues to repair. Transmissions typically cost upwards of a thousand dollars to fix and, if not functioning properly, can render a vehicle completely immobile and unusable. When a transmission begins exhibiting signs of problems, it should be taken to a transmission expert and serviced as soon as possible to avoid incurring serious damage. In some cases, catching a transmission problem early can prevent transmission failure.

Transmission Fluid

Check your transmission fluid. If your transmission is low on fluid, or if the fluid is old and discolored, it could be to blame for the hard shifting. Hard shifting can occur due to a lack of lubrication in the transmission. Transmission fluid should be reddish in color and largely transparent.

Sensor Problems

Most modern vehicles are equipped with a wide assortment of sensors, including those that control how and when your car's transmission shifts. If the sensors are not receiving the correct signals and readings, it can lead to shifting problems. Hard shifting may be caused by a slow sensor or one that is transmitting the wrong signals from the engine. A faulty speed sensor may be to blame for reporting that vehicle is running more slowly or more quickly than it actually is.

Vacuum Problems

Problems with the vacuum lines on a transmission have been known to cause hard shifting. Clogged, bent or disconnected vacuum lines affect the pressure in the transmission and can cause rough shifting to occur.

Error Codes

The transmission control module on your car stores transmission error codes. If you are having a difficult time diagnosing why your transmission is shifting hard, you can take your vehicle to a transmission service mechanic and have these error codes read. These codes should give you a good idea as to why your transmission is shifting hard and how it can be repaired.


Helpful comments on this video:

  • My 2006 Dodge Charger SXT 3.5liter had 301,000 miles, when I changed the fluid. It had a lot of that dust built up on the bottom of the pan. I probably should have changed it when I bought the car, with 223,000 miles on it. I didn't know if the pervious owner ever changed it ir not. I don't think she ever had it changed. Especially since they try to claim that you never need to change it. The fluid lasts the lifetime of the transmission. Yeah, when it fails from not changing rhe fluid, that is the lifetime of the transmission. When I saw how bad it was, I changed the fluid in my 2011 Dodge Charger RT 5.7liter Hemi. It had 182,000 miles. That one was much cleaner. LOL Definitely change your fluid more often, even when they say it's lifetime fluid. The 2006 SXT is startimg to have a little engine noise when accelerating from a stop, as it warms up. It now has over 307,000 miles. Sounds like the rockers are wearing out. Could be the cam too. I'm sure it needs the transmission rebuilt. Shifting from reverse to drive, or drive to revers is a bit slow, waiting for the slack of worn out clutches to grab.
  • I just replaced my tcc and still shifts hard after the car warms up

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