Will a bad CV shaft cause the car to roll in park?

[lxpeery]

Sorry to start a new thread about the same car a day later, but diagnostics have continued and I'm now pretty confident that the issue is not the transmission.

Symptoms: Gearshift does nothing. No movement in drive or reverse. Car rolls in park as if it were in neutral.

Got under the car today to play with the driveshaft, as when I bought the car I was told that the issue was the guibo, which is rough, but not so bad that the transmission and driveshaft are disconnected. In park, the driveshaft is nice and locked down. Put it in drive, everything spins... except one rear wheel. Looking closer, the CV shaft spins, but the wheel does not. Spinning the wheel by hand has the opposite effect. So I started the car up on the lift, put it in drive, and sure enough, one rear wheel spins, and the one with the bad shaft sits still.

Drivetrain stuff has never been my forte, and I've never owned a car with an open differential. But by my understanding, the "no movement" issue makes perfect sense if the shaft is bad. Open differential -> wheel with least resistance spins -> since no connection between shaft and wheel, power never makes it to wheels and car no go. Does that explain the rolling in park thing too? Since the driveshaft is locked down in park, I know the issue there is somewhere between the rear wheels and the differential, but I'd think the same deal with the whole not moving situation would apply. Since there's a point in the system with no resistance where there should be, it allows the wheels to spin even when the driveshaft is not.

Does that sound moderately sane?

[moroza]

Yes, rolling in park and moving in gear are physically the same thing from different frames of reference. With an open differential, one disconnected axle will allow the other to spin even with the driveshaft locked.

[demetk]

With an open diff if you spin one wheel by hand the other should spin the other way. With limited slip diff both wheels will spin in the same direction. Maybe one of your half shafts is severed?