Vibration At 40-50 MPH And 75 MPH +

Justrynamakeit

New member
Jun 4, 2020
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2003 2500 SWB Running 35’s. For no apparent reason I developed this shake/vibration. Most noticeable in the seats, not steering wheel. During acceleration at 40-50 MPH and then above 75 MPH. Checked tires, running true (not out of round) and balanced. U-joints “appear” to be Ok as they are tight with zero slack. this vibration came from nowhere. No off-road. No mud. No towing. Just simply everyday driving. Is also very noticeable when at highway speed, simply take foot of accelerator, as truck slows, no vibration until 50 MPH through 40 MPH. Disappears as soon as truck slows below 40 MPH. What should I look at next? Vibration/shake is not noticeable at any other speeds. Thanks.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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4,863
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Phoenix Az
2003 2500 SWB Running 35’s. For no apparent reason I developed this shake/vibration. Most noticeable in the seats, not steering wheel. During acceleration at 40-50 MPH and then above 75 MPH. Checked tires, running true (not out of round) and balanced. U-joints “appear” to be Ok as they are tight with zero slack. this vibration came from nowhere. No off-road. No mud. No towing. Just simply everyday driving. Is also very noticeable when at highway speed, simply take foot of accelerator, as truck slows, no vibration until 50 MPH through 40 MPH. Disappears as soon as truck slows below 40 MPH. What should I look at next? Vibration/shake is not noticeable at any other speeds. Thanks.

means nothing, pull the driveshaft and actually twist them around. see if any are seizing up
 

Justrynamakeit

New member
Jun 4, 2020
2
0
1
Thanks for the prompt reply. Will inspect again. Hell, its a simple job. Will replace both u-joints and update this post.