I have an old, circa 1974 Hurthgearbox, HBW 15-21 ? (The plate has been painted over) Runs perfectly but the shift is very stiff. Any suggestions. Oil level is normal.
With the engine running, I can shift in forward and reverse without any problem. When the engine is off, I can not shift it into reverse, but forward and neutral are ok. I have a folding prop.
Any ideas what may be the problem?