Hey, how's it going guys?

1989 jeep cherokee 2wd 4.0L

I really need some help on this one. I've been all over internet forums and everything, still unable to find anyone that has a problem just like this.

Whenever I attempt to start the jeep it makes a knocking grinding noise down in the bellhousing area. It only does this when starting.

I just had the flexplate replaced yesterday. The starter was also replaced yesterday. It was still making the grinding noise when starting.

I'm trying to figure out what could cause this...
the flexplate came from Autozone :FRA-333
the starter is also from Autozone: 16848

The CPS sensor is also new. I even cross referenced a couple different sites to see if there were starters with a couple different specs, but they all seem to be 10 gear starters.

I'm on the verge of taking it to a jeep specialist here in new jersey, because I need to be able to take the vehicle down to NC next week.