Standard three speed trasmission stuck in first gear

[meathead42]

I have a 1973 454 Chevy k20 pickup that was stuck in first gear. I pulled out the shifter because I figured it was broken but it was fine. I then shifted the transfer case into 4H and the truck started shifting ok. Is this a coincidence and there is a real problem, or is there linkage from the transfer case that locks the tuck into first gear? I had a CD case stuffed in between the seat and 4WD shifter that could have moved it up a bit. This is the transmission that has the grandma gear and then three other gears.

The truck does not get driven much but when it does it pulls a trailer to the hills and I would hate to have that happen in the mountains. Any info on this transmission would be appreciated!

Thanks!