When I was in the hunt mode for a Cherokee, I noticed the door locks were somewhat hard to use. (sticky, gummy, stiff???)
I finally just bought a '99 Sport and it is pretty much the same. They all work, both by power and manually but in my mind they seem a little stiff.
Is this normal?
Should I get in there and hit 'em up with contact cleaner like CRC?

 

I would say it's worth getting in there and lubing everything you can to make the actuators job easier. It's a pretty simple system. Everything is connected by rods with little plastic elbow connectors. The actuators are not serviceable and once they fail you have to replace them. I have two failed ones on my '98. They make noise but do not move the rod. I was quite surprised at the replacement cost. I grabbed a complete replacement set from a grand cherokee last time I was at the pickapart. If you don't want to take the door apart, you can just lube the exposed lock mechanism to make it move as easily as possible.

 

I like it simple. I can start there and if needed, then I'll go inside.
Thanks.

 

I'm doing some work on my '98 today. I still haven't put in the two replacement actuators. If I get to that today, I'll snap a pic. It doesn't take that much to get the door cards off. the back is a lot easier than the front. I have to replace the drivers and the rear passenger side.

 

I finally got around to swapping out the two bad actuators today. It was the drivers door and rear passenger door. I had gotten a complete set of actuators from a Grand Cherokee since they looked the same. Turns out the drivers door is slightly different, but I was able to swap the little gear and it worked great. Here are some pics if you are interested. I did not have any lightweight grease handy so I did not lube them. If I get really motivated, I'll take them back out and clean/lube wherever I can.
First pic is the part that faces inside the door where all the rods attach. Second is with the cover plate removed. You can see the plastic gears that do the work. That's a good place for some lightweight grease. I had to swap the black piece above the white gear. The Cherokee one has a clip there, the Grand Cherokee one does not. I was able to just lift it out and swap it. The pic with the springs is the other side with the back plate removed. There is some light lube there. The large circular piece is what moves against the anchor on the door. You can shoot some WD-40 in there or some lithium grease. Last pic is what goes on top of the springs.
The only weird part was that locking would not work unless I had the door panel screwed in. Not sure if there is some ground connection that it completes. Just makes testing harder.
All my locks work now, but I know I should go back in and lube them.

 

Forgot to check in on my thread...
Thanks for the pictures. No wonder the locks feel like they're swimming in wet cement. That's a lot of goo in there that needs to be cleaned and reapplied with modern day lightweight stuff.

Guess this goes on the list of things to do when the weather gets better.

 

Just be careful when you take the plate off. The curved spring in that channel will want to pop out. It's pretty easy to pop it back in. A clean/relube should make them move a little smoother. The plastic gears have some white (what appears to be lithium) grease on them.