We tried to start our 8N this morning by pulling it, as we have done before after I let it sit too long. It rolls fine in neutral, and in gear with the clutch down. When I let off the clutch in 1st and also in 2nd gear, the rear wheels only skidded and would not turn. The brakes were not engaged. Is it possible that the transmission is stuck in reverse (?), although I can find no problem with how the gear shifter feels when I shift it; it feels tight and sounds engaged in each gear. Any thoughts on this would be most appreciated as I am stumped. I fear the worst, that the transmission or differential is locked down. Thank you.