I’ve got a similar sound…like hitting a golf ball with a metal driver when selecting fwd and rev. Been troubleshooting it for a while and as part of other projects I have changed the rear driveshaft CV joint, all Guibos and the center bearing support. I added longer splines a few years ago too.

Nothing has worked unfortunately. I think it has to be either the rear driveshaft u joint, which seems very tight, but I can’t put hundreds of foot lbs on it. Or the transfer case. I’ve got a transfer case chain project on the horizon, so if that doesn’t work then I think it must be the u joint in the rear driveshaft.

Forgot the rear diff rebuild, that’s new too, with no change in the “ping”. I don’t think that u joint can be changed out or repaired, and new driveshafts are expensive.

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Current
Original owner 2002 E53 X5 4.4i to 4.6i swap
2026 G80 M3 6 spd
2025 G06 X5 50e
Former
1972 Audi Fox
1986 Saab 900S
1996 BMW Z3
1998 BMW E36 M3 Sedan
2004 BMW E46 M3
2006 Audi A3 Quatro
1993 Mopar 318 Jeep Grand Cherokee
2015 V6 Jeep Grand Cherokee