Driveline Vibration

[Mkelcy]

I've got an odd vibration in my '68 Camaro.

Basics are T56 transmission, Ford 9" rear, 4.11 gears.

I get a vibration as the car is transitioning from driven to coast - that is, there's no discernable vibration while I'm giving it throttle to maintain speed; when I let up there's a vibration; and then when it's fully coasting, there's no vibration again.

A little internet searching suggests that it's the rear universal, although the driveshaft has fewer than 5,000 mile on it from freshly rebuilt. I don't mind swapping the universal, but wondered if there was anything else I should check as well.

Thanks in advance for any suggestions.

[Reckn8]

You could fill pages and pages about this problem. Lot's of variables with this problem.

[WallaceMFG]

You could check the pinion yoke and gear backlash. Maybe something has come loose

[TheJDMan]

Is this something new or has it been vibrating for a while? If it just started it could be an indication that something is coming loose.

[chpr1972]

Did you check drive shaft angles. Tremec has a gauge app for your smart phone. It works real good. It takes the math out and gives you a green[ good] reading or a red[ bad] reading. It took me many tries with raising the rear of the trans to adjusting upper control arms to get a green lite.

[chpr1972]

That is rear upper control arms.

[andrewb70]

Mike,

Did you ever figure this out?

Andrew