95 F-150 Starter problem

Have a 95 F-150 with 300 6cyl. Put a new starter in 6months ago, recently have gone to start truck and it won't turn over just clicks like when the starter died, I'll roll the truck a little and it starts up. Is it just that the teeth aren't matched up? Odd thing is it usually only does it when I park on a incline with the bed end lower. Any ideas?

Well, I have a 94' f150 and my starter has constant power to it from the battery (big cable on the stud) with a switched power from the firewall relay to the solenoid ON the starter (little blade connector). So, when you start your vehicle really all that's happening is the little wire with the blade connector gets switched power from the firewall relay and activates the on-starter solenoid.

I'd assume you either have a bad connection somewhere or your starter is dying. Try tapping it with a hammer underneath the truck the next time it acts up and see if that fixes it, if it does you need a new starter. Just tonight I replaced the mini starter (with that onboard solenoid) with a bigger one that does not have an onboard solenoid. This new starter is bigger and cranks it over alot faster and easier. I'd buy one of those if I were you, although you might have to do a little modification to get it to work.