Truck- 1996 F150 XL 4x4,
Engine- 300 Inline 6
Transmission- 5 speed Manual

I bought this truck used early in the new year of 2023. A lot of issues were not disclosed at all. The latest issue is I needed a new starter. Old one packed it in, or so I thought. The problem being, and from my understanding, the 1996 300I6 was the last year of this motor being manufactured. Fiding parts can be a gongshow. Yet starters are available. However, it appears they are not exactly a perfect 100% match.

Lately the starter has been acting up. Or it's the flywheel....or both. at least 70% of the time the starter gear sounds like its just grazing the flywheel or spinning freely.. On inspection both starter gear and flywheels teeth are smoothed down and rounded off at the points. The flywheel as well does have a few missing teeth. Not many, like 4 at single points around the whole wheel.. Sometimes after re and reing the starter, i've noticed the flywheel stopping at the starter right where a tooth is mission. I know it needs replacing. yet I also know I have a clutch job coming up and only wanna rip it all apert once.

Looking at the starter during a bench test eyeballing it strate on, I noticed the gears do not come out past the starter bell housing very far. It actually looks like only 25% of the gear itself is visible past the housing. Should it not be at least twice that when engaged. To me it looks as plain as day. the gear in the starter is to small. with that being said, is it possable to install a bigger gear. All I think I need is another 1/4 inch and the flywheel would be engaged all the time.

Good thing I have a 5 speed manual cause now im always parking on a hill.

 

if there are teeth missing from the flywheel ring gear, ant the remaining teeth are rounded tips, the ring gear is shot and needs replacing.
my bet is that you are using store bought rebuilt starters too. most of the "rebuilding" services only replace what is visible bad. and they usually do not look at the gear, or bendix. replace brushes, clean it up, test for spin with no heavy current draw and send it out as "rebuilt"
i only deal with a local rebuilder. he knows his name is on each unit that goes out of his shop, and as such he goes over each unit with a fine tooth comb. and they are usually cheaper than store bought junk too.

 

Another possibility is that even though you bought a starter for a manual transmission, you could have received one for an automatic transmission which is why it doesn’t properly engage the flywheel.

 

Replace both the ring gear, and the starter (again)