[HWYSTR455]

Originally Posted by Nicks67GTO

Heres a question for you vibration guys since we are on the topic. Could it be a slightly bent pulley? I have a bad vibration that comes in after 2500 RPM and gets much worse with vehicle speed but its never present before 2500rpm in any gear and it only shows up strong in 3rd 4th and 5th.....I think I have a crank pulley that has a small bend in the outer portion of the ring from when I put in in a tire to haul it. Its not messing with the fan belt but the bend is obvious. Im going to tap it back in place tomorrow and report back. I guess im thinking out loud since we are on the topic.

Nah, since it's gear related, my guess it's behind the trans. Do you have a spare slip yoke? If so, pull the shaft, slide the spare in, and see if it wiggles. First guess there is the tail housing bushing/bearing is bad.

With the car on the ground, how much remaining 'slip' area on the yoke is showing? Same question when it's on jack stands and the suspension is drooping?

When the shaft is out at this point, take a close up of the rear yoke and post it. Also, grab the rear yoke and wiggle it. A pinion bearing is also a possibility.

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