speaker size

what size speakers fit in the back tailgate? 6" x 9"
and in the door panels? I think the doors are 6" dia..

Those are just the covers. Inside they're 5 1/4 inch. At least, they are on my '88.

The ones in the doors are 1-way. There is a small high freq speaker located in the lower dash.

The rear are 2-way.

Yea they are 5 1/4 all the way around on older models, but on newer Cherokee’s you can (supposedly) get 6 1/2’s in
the front. I however had a problem with depth in the front of my ‘99 because the magnets on the speakers were too
big and they were interfering with my window rolling down so keep that in mind when you choose your speakers.

I read you could get 6x9's in the gate if you cut some of the fiberglass out. That was easy, just take off the plastic cover and use snips or a saw.
The pain comes if you don't check the depth first. Some speakers are deeper than others, the specs are always on the box. I actually ended up cutting a square out of the plastic cover to fit a wooden mount in for the speakers. I only needed about 1/2 inch and it worked. It was ugly till I dressed it up and anchoring to the fiberglass can be tricky. Make sure before you drill, fiberglass isn't very forgiving.

Worth it but won't ever try again.

P.S. Front doors are 5 1/4, I did the back because I felt brave after making bigger holes in front for 5 1/2, very easy

I read you could get 6x9's in the gate if you cut some of the fiberglass out. That was easy, just take off the plastic cover and use snips or a saw.
The pain comes if you don't check the depth first. Some speakers are deeper than others, the specs are always on the box. I actually ended up cutting a square out of the plastic cover to fit a wooden mount in for the speakers. I only needed about 1/2 inch and it worked. It was ugly till I dressed it up and anchoring to the fiberglass can be tricky. Make sure before you drill, fiberglass isn't very forgiving.

Worth it but won't ever try again.

P.S. Front doors are 5 1/4, I did the back because I felt brave after making bigger holes in front for 5 1/2, very easy

On my 97 Cherokee Sport with premium sound package the rear speakers are in a separte "sound bar" on the roof which you can get from Chrysler Jeep. Just take the speaker wires out from the tail gate where the flex part of the harness goes to the tail gate. You can also get aftermarket enclosures at Best Buy electronics. Just a suggestion.