Timing belt or chain.?

I have a 99 Grand cherokee. I am not sure if it has a timing chain or a belt. Is it easy to change and how do I do it please?Timing belt or chain.?
For the record its a timing chain.

If you're thinking about belt replacement you probably mean the serpentine belt. It turns accessory drive (starter, alternator etc). These can be replaced in your driveway with the proper tools, if your timing chain is bad you should take it to a shop like the others have suggested.Timing belt or chain.?
You take it to a garage and ask them to do it. If you don't even know if it's a belt or a chain, you really shouldn't be playing with it.Timing belt or chain.?
Unless you are good with cars, get a professional to fix it. You have to remove the water pump, as well as several other major parts. You will also have to set the timing, set the tensioner, reseal the water pump, and put everything else back on.Timing belt or chain.?
It should be a belt. but i would get it changed by a mechanic. you need the right size belt plus it needs to be tightly put on there or it would slipTiming belt or chain.?
You have a chain. Why would you change it? They, with oil changes, should last as long as the engine,,Yes, they will stretch, but unless you have so much wear that it is hitting your cover, you will not know it is there.

IF..and I say IF.. you are competent with mechanic work, and you have the four liter.....SHORT VERSION. Pull the fan and clutch, shroud, water pump...you CANNOT RESEAL THIS AS SUGGESTED,,but good time to change it any way, pull the serpentine belt ,using a puller, pull the crank harmonic dampener, pull the timing cover off, note the marks on the crank sproket and cam sprocket and line up NOW. Pull the center bolt holding the cam sprocket and slide the two sprokets off together. You WERE planning on replacing the two sprockets too, weren't you?? DO it as a set or chain wear will be accerlerated. Clean all gasket material off and lossen the first12 bolts of the oil pan..If you damage the gasket on the oil pan, you will have to pull it too and replace the gasket..be careful. Line up the timing marks on the crank and cam sprockets and slide, with the chain, back into place.

Oil the chain with 30 w engine oil and reverse the above procedure..Note, use a harmonic INSTALLER, never the bolt on the crank to pull it on..Yes, it MIGHT work, but damage the crank threads....DON't even think of it..These pullers and installers can be borrowed from larger auto stores.

If you are NOT useing cork gaskets,,you can use RTV sealer on the various gaskets.

This is the SHORT version, but gives you and idea how to do. Time,,depending upon Murphey's Law around four hours..If you have to pull the pan..add two more hours..minimum.

Good Luck,Timing belt or chain.?
Timing Chain. Goto your parts store and pickup a repair manual. It does require removing most of the accessories on the front of the engine including the fan assembly.