Checking u joints

[66FBCharger]

What is the best way to check for bad u joints?

[Hard Charger]

get under the car and see there is play in the drive shaft, see if it wiggles. what happens is the grease drys out and the bearing get pulverized. look for dust or burnt marks around the cups.

I always found my bad u-joints by the vibration or squeak while driving.

[Cooter]

Remove drive shaft and rotate full motion. Only way to tell if rough spotted is by feel.
I've seen no play in shaft in car, but once removed, joints are dry and needle bearings worn into cups.

[66FBCharger]

Great! Thanks.
I will check them this weekend even though I think I found my vibration. The trans. mount was broken allowing the trans to move to the driverside of the tunnel.

[John_Kunkel]

I'm of the opinion that the only accurate way to check the condition of a u-joint is to disassemble it. Because the rubber seals can mask play, lots of joints that will feel tight on a "wiggle inspection" will show brinelling  on disassembly.