2001 suburban, started this AM, put it in drive, car wouldn't move.
Put it back in park, then reverse, still no go. After shutting off the ignition, the car then wouldn't turn over. Just grinded. Parking break not engaged, but car didn't seem to shift into gear.
Sounds like you have a shift linkage issue.
top off your trans fluid, let it sit then try again later, if it doesnt work have it towed and looked at deffinately sounds like the shift linkage.
Sounds low on transmission oil, but how did it get low? When you say grinding do you mean more of a clicking noise?
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