07 Tahoe vibration

[smoose]

Have 07 Tahoe. 236,000 mls. New transmission, brakes, tires, motor and transmission mounts in last 9 months. Have vibration and humming over 30 mph. If take cruise off or let off gas pedal it stops. Any ideas what it could be?

[Jsdirt]

Sounds like you might need some new universal joints.

 

Get the rear wheels in the air, vehicle in neutral, and see if there is any play in the joint. Spin the shaft and check it in several different places on both the front and rear joints. Any play and it's done for. If that doesn't reveal anything, remove the driveshaft, then move the different sections - on the front just move the yoke in a circle, and up / down & left / right. On the rear you can spin 2 caps with your fingers, and the other 2 can be checked by moving the cross - this should reveal any issues. Everything should move smoothly, with no binding or roughness.