Shaking when accelerating around 35 to 50 mph

1998 CHEVROLET SUBURBAN
197,000 MILES • 6 CYL • 4WD • AUTOMATIC
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DYKEMANBLAIN
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Like the title says, it starts shaking or vibrating between 35 and 50 mph. Only when accelerating. I took it to Les Schwab and had everything balanced and aligned. Still shook. Had Midas replace both front axles and it still does it, but it does seem to be a bit less rough. Still testing. Any suggestions?
Apr 17, 2019 at 8:58 PM
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SCGRANTURISMO
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Hello,

This could be a problem with your U joints. Your vehicle's drive-line connects to the transmission and differential with U joints that allow the drive-line to move up and down snd still rotate and provide the rotational torque from the transmission to the differential where it is applied to the wheels, turning them. The U joints have needle bearing that need grease to work properly and when over time or lack of greasing wear out. When this happens it will cause that drive-line the be out of balance causing vibrations.
I have included a couple of links down below for you to go to:

https://www.2carpros.com/articles/jack-up-and-lift-your-car-safely
https://www.2carpros.com/articles/how-u-joints-work

Please go through these guides and get back to us with what you are able to find out, please.

Thanks,
Alex
2CarPros
Apr 17, 2019 at 10:46 PM
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DYKEMANBLAIN
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  • 3 POSTS
I had new U joints put in when they did the alignment. The only thing I can think of is that maybe either they was put in wrong or the new axle was. But don't want to bring it up if it might be something else.
Apr 18, 2019 at 12:03 AM
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SCGRANTURISMO
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Hello again,

It could also be a motor or transmission mount. It's pretty funny, I am tracking down a similar problem on my Mustang. Check them out and get back to us with what you find out, please.

Thanks,
Alex
2CarPros
Apr 18, 2019 at 12:15 AM