it could be happen, that you have lack of grease / oil in the drive shaft joints.
Please try as following:
At the inner joint (Gearbox):
- press with two fingers around the collar, to put the grease into the joint
At the outer joint:
- try the same if it's filled with grease (not original, but frome time to time done)
- if it's filled with oil, check the collars for leaks
Any more questions, please ask.