After some deep thought I have put together a list of some of the things I can think of that could cause your transmission to stick in second gear.
!. Clutch not releasing fully.
2. Burred or battered teeth on sliding sleeve.
3. Burred or battered transmission shaft.
4. Frozen synchronizing clutch.
5. Stuck shifter rail plunger.
6. Gear shift lever twisting and binding shifter rail.
7. Lack of lubrication.
8. Improper lubrication.
9. Corroded transmission parts.
10. Also, just in case,- Second speed transmission gear bearings locked will give same effect as gears stuck in second.

There are probably other reasons but my head now hurts from thinking (not used to that-LOL) and if I happen to think of other reasons I'll let you know. But, this should cover all of the more common reasons.
Good Luck!!!


Oly in Oregon

Rest in Peace

1945 GMC COE Victory Truck
1953 Willys CJ3B
1955 Chevy 1st series 3/4-ton
1958 WIFE Last series

Never say "Whoa" in a mud hole