Starter not working

Electrical problem
1987 Ford F250 V8 Four Wheel Drive Manual

We have a 1987 Ford 460 with a T19 Transmission in it for our farm truck. The problem first started, I think, when we had a worker replace the clutch in it. When he put the transmission back on the engine he didnt put the plate that goes in between the bellhousing and the engine. The starter worked for a while after that but then went out. We replaced it and it lasted about a week. We replaced it a couple more times after that but the starter wouldnt last more than 2 weeks. Spring came and we didn't need it anymore so we just let it sit. Last week we brought it in our shop and I took out the transmission and just had the bellhousing mounted to the engine, and used some washers to space the starter away from the housing, which is what the plate did. I watched it engage a couple times while someone started the truck and it worked just fine. I put the transmission back in it and now it makes a terrible noise when it engages and sometimes it even gets stuck out and wont go back in. The threading on the bellhousing was bad so I just drilled a hole all the way through and put a bolt through with a nut on the end, thinking the starter wasn't tight enough against the bellhousing. Any ideas on how to fix it?

Thanks

Starter will not disengage when the key is turned off.I have changed the starter re-lay, the ignition switch on the steering column, and had the starter bench tested. The starter worked fine, and the starter solenoid worked good. The ignition switch was changed out and was working fine. One day it just started to have this problem. Could it be the new ignition key switch. Please help. Thank you.

My truck is the 7.3 idi diesel. When I put the key into the ignition and over to the start position all the interior lights come on so the battery isnt dead, but when I do so it doesnt start to turn on. Basically nothing happens. Ive replaced the starter solenoid, and the glow plug relay, could it be something to do with the starter switch? Thanks

1984 Ford F-250 V8 Two Wheel Drive Manual

I have an 84 diesel ford f250, Have replaced key switch ignition switch and starter but still have same problem. The starter wont shut off even after key is removed. Dosen't matter if engine starts or not. Is intermittent.