If I need to slow down quickly from highway speeds there is a substantial grinding noise that comes from the transmission area of my 99 GCL. You can hear it in the cab and feel it in the 4x4 shifter. I have no idea what it could be. Any ideas?
Old fart with a wrench
What T-case do you have? Is it an AWD model? Check your upper rear axle control arm mount. If it's broken, the axle will try to turn with the wheels under heavy braking, pulling on the driveshaft. This could also transmit noise by pulling the trans mount down to contact the frame. This is all I've got.