been wanting a xj for awhile now and I finally got a chance to pick one up from a friend, when im on dirt roads around town In like 1st gear if I give it gas it makes a tick it sounds like a loose flex plate bolt hitting tin. it doesn't make it all the time only happened a couple time out on the trail under a load. and then I have a squeal that I thought was a tensioner pulley, I replaced it and the noise is still there it sounds like a chirp chirp chirp

 

It's easy to check the flex plate. They have been known to crack, or if you're lucky, the bolts come loose.

Pull the small plate at the bottom of the bell housing and check it out. If it's loose, you may just need to tighten it up. If it's cracked, better to find out now than when it completely gives out.