Awal615

I dont knw if im under the right platform model but my son in law has a 2006 a4 2.0t. He just had a new head installed and that feels good now but his father said when he had the front end up on jacks he said when he spins the passenger tire that the driver tire wont spin with it. He thinks its a broken axle or rack and pinion. Anybody know why this happens im thinking with no pressure on tires is why its not activating the differential. Can anybody help me explain to his dad why this happens

turbo510

If it had a broken axle, it wouldn't drive at all. Rack and pinion has nothing to do with the differential either. Perhaps one wheel has some brake sticking due to rust, etc, and rather than the wheel turning, the transmission's output shaft (in Neutral) is what's moving.