Wheel clunk on 76 coupe

[Nigel curry]

Hi all, here’s a strange one,I have the car up on stands (all four corners)and all wheels off and engine running now when I select drive the passenger side rear obviously turns but there is a visible jump and clunk at regular constant intervals (think going over a speed ramp)everything jumps looking right back to the diff.There is nothing on the drivers side and it turns smoothly I am hoping someone may have an Idea what this may be
Thanks in anticipation Nige

 

[Mad4slalom]

Hi all, here’s a strange one,I have the car up on stands (all four corners)and all wheels off and engine running now when I select drive the passenger side rear obviously turns but there is a visible jump and clunk at regular constant intervals (think going over a speed ramp)everything jumps looking right back to the diff.There is nothing on the drivers side and it turns smoothly I am hoping someone may have an Idea what this may be
Thanks in anticipation Nige

I think I would be checking propshaft and driveshaft uj’s first

 

[antijam]

With the wheels off I assume the rear suspension is at full droop. I wouldn't feel comfortable with the engine running in gear on four axle stands myself - much safer with the front wheels on the ground. However, at your own risk I'd - VERY CAREFULLY - jack the trailing arm to nearer it's loaded position, making sure that the car is not lifting off the rear axle stands, and see if the clunk diminishes or disappears. With the trailing arm fully drooped the drive shaft UJ's do not behave like CV joints.

 

[Roscobbc]

With the wheels off I assume the rear suspension is at full droop. I wouldn't feel comfortable with the engine running in gear on four axle stands myself - much safer with the front wheels on the ground. However, at your own risk I'd - VERY CAREFULLY - jack the trailing arm to nearer it's loaded position, making sure that the car is not lifting off the rear axle stands, and see if the clunk diminishes or disappears. With the trailing arm fully drooped the drive shaft UJ's do not behave like like CV joints.

/|\
What Antijam sez!
Valid remarks about UJ's vs CV joints.
Reminds me of my very first 'car' - a Berkeley T60. That was front wheel drive with a 328cc 2 stroke twin powering it. Drive shafts had UJ's at each end (much like a Vette). If you were unfortunate enough to pull out of a junction and turn hard right/left it would put the UJ knuckles at an extreme angle. The resulting drive shaft 'surge' as the 'knuckles' were being forced around would look really amusing to pedestrians and perform rather like driving a yank with a Detroit Locker........ presuming of course that the Berkeley's differential drive train didn't snap first due to the extreme resistance of the 'knuckles' being forced 'over centre'!

 

[Nigel curry]

Great advice/info thanks lads,in my defence the car wasn’t jacked up to investigate the clunk it was to check out a gearbox problem and it was only running a minute or so BUT I DO TAKE THE POINT thanks again
Regards nige