Cat 922B starter problems

Sounds like time to replace the solenoid or solenoid contacts. They don't last forever.

some of those older solenoids you can remove the end cap and turn the positive posts 1/4 turn to get new contact points, but this one sounds like the motor is spinning ok, but not engaging, maybe your pull in winding is shot. regardless, clean all the connections on the solenoid as an initial test.

One possibility not mentioned is that the overrunning clutch on the starter drive may be bad. Normally if the solenoid "crank" terminal is energized, the starter motor will not try to run without the drive gear at least grinding against the teeth of the flywheel ring gear. If the solenoid is bypassed during testing by shorting between the two large terminals, the starter should spin without attempting to shift the pinion.

I haven't had a chance to check out the solenoid and contacts on the starter yet, but the other day when trying to start the engine the starter would engage the flywheel for just a second and crank the motor just a tiny bit then disengage and free spin within the housing. So it is trying to spin the flywheel but it won't stay engaged long enough to start the engine.

If its only used occasionally, is it possible the shaft is rusty not allowing full engagement?

I would like to thank everyone that replied to the thread, I was given a lot helpful information and a solid starting point that was helpful in diagnosing my particular starter problem, in the end it turned out the drive gear on the starter had almost completely sheared off all of the teeth and that was ultimately my issue. Thanks again for all of the helpful information.