Cardan shaft / drive shaft
That a cardan axle (= drive shaft)should have no play seems logical to me. Play on the universal joints can not only cause vibrations, but also cause front axle or gearbox bearings to break fairly quickly afterwards, and thus expensive to repair. Besides, when a driveshaft comes apart plane the damage is unforeseeable.
Universal joints are for sale, here on the site. Replacing them is really not difficult, if you have a semi-automatic ( MIG ) available.
I have 2 hand driveshafts & overhaul driveshafts in stock. Mail me for this.
BUT what few technicians know, the position crossheads of a cardan is not. Many think 90° to each other is the perfect solution, but Mercedes & Puch prescribe otherwise.
Cardan front 78° angular rotation
Cardan rear 120° angular rotation
Cardan from gearbox to intermediate gearbox 0°