Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
did this happen out of the blue one day ?
is the check engine light on ?
when this happens i am sorry to say the 3rd gear clutches are burned out or the forward sprag gear clutch is not holding
those are the only things that will cause this problem
if the fluid is filled up i am sorry to say the transmission needs to come out and apart to inspect both to see which one is bad
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how are you making out ?