Hi all
looking for some practical experience please. Car had it's tires replaced after using the old ones for 18 years. Started to get bad flat spots that you could feel if driving 80kmh and over. So I took the car on the freeway 2 to 3 times just a small stretch to test everything driving at 110kmh. I picked up that when I am taking the off ramp and letting go of the accelerator pedal completely there is a soft funny noise or feeling like a very slight quick frequency vibration. When I give little gas it goes away. Can this be worn uni joints? At a constant cruising speed it is smooth with no issues.

Yes, a slight vibration when going at fast speeds (for me it was around 80kph, and then smoothed out by 100kph)

The other time the U-joints were bad, the symptom I notice was a clunk when going from First to Reverse


It is easy to check the U-joints:
* Block the front wheels
* Jack up the rear of the car and support with jackstands. This will allow you get under the car, *and* will help lesson the amount of oil that may leak when you pull the tailshaft out of the transmission
* Remove the four nuts that fasten the driveshaft to the differential
* Lower the rear of the driveshaft (do not pull it out of the tranmission)
* Flex the rear flange in all directions

If it flexes smoothly, all is good

If it flops around (no resistance), then it is worn

If it binds in any direction then it is bad


You can do the same for the front slip yoke U-joint by pulling it out of the transmisson and flexing the yoke

Thanks DD
There are no clunks at all. I will try your test method when it is a bit warmer as we currently have winter here.