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Q: My truck is shifting back and forth really hard

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Every time I get between 40-50 MPH, my truck will up shift and down shift almost continuously until I speed up or turn off the overdrive. It causes the truck to jerk and shudder. And once I turn the overdrive off, it will not up/down shift continuously anymore. So I usually drive it around town with the overdrive off. But when I get on the highway, I have to wait until I get it over 50 MPH before turning back on the overdrive. Do you have any idea what this may be? Is it an easy fix or do i need to run my truck into the river? :-( ... I need to find the least expensive way to repair this issue. I am mechanically inclined, so doing it myself (within my capabilities) isn't too much of an issue. I certainly cannot afford to replace the transmission...any help or advice would be greatly appreciated...Thank you in advance...

My car has 105000 miles.
My car has an automatic transmission.

A: Hi there, thank you for your question. I am...

Hi there, thank you for your question. I am going to try to help you but I can't promise anything. I had a truck do that once. I drove from Texas to Georgia towing a car, when I got to Atlanta, GA, when shifting into 2 or 3rd gear it would sounds like I hit something. Sounds like something that you could be going through.

My first suggestion is to change your transmission fluid and filter, which fixed the problem I was having. I would also look at your engine mounts and transmission mounts.

You may also look at the linkage to your transmission and make sure it's tight and properly connected. Also, you have a transmission input speed sensor and an output speed sensor, it sounds like one of these may be failing on your but you didn't mention any lights on in your truck which would indicate that they are faulty. If this doesn't work and you still find your transmission having the same problem, you may need to have your transmission rebuilt. Your best bet may to have a local professional diagnose the shifting problem firsthand and then proceed with proper repairs.

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