I have a recently acquired 1993 4.0 liter YJ with a 4 inch lift and 33x12.50's. It has approximately 210K miles (actual is unknown as the speedo/odo apparently haven't worked since it had 115K). We just took it on vacation with us to Chincoteague, Va. (About 175 miles one way). I wasn't driving it as I was hauling the travel trailer, but the wife said it drove fine except for a tapping noise she was hearing. I thought it was probably a noisy timing chain she was describing and didn't think anything of it until I drove it.
I am definitely hearing a metallic tapping sound coming from underneath that sounds more like it is coming from the passenger side middle of the tub area. It is regular and changes speed with the speed of the vehicle, pushing in the clutch has no effect at all. I haven't messed with the transfer case yet because I don't want to start any issues with getting it stuck in 4wheel drive at least until I get it home. It sounds almost like maybe some slack in a u-joint maybe to me, at least that is what jumped in my somewhat limited mind anyway. Now we just replaced the passenger side u-joint on the front wheel a few weeks ago as well as the long steering arm that I would describe as the tie rod end except it is about 3 feet long, but I don't know what it is really called, (this is my first actual jeep so bear with me guys, I am trying to get up to speed
)I also just put a used exhaust from the cat back including a Dynomax muffler and tailpipe on it right before the trip, but I used new exhaust clamps and isolators and it doesn't sound like the exhaust banging at all.
I was speaking with a mechanic with 20+ years experience, that was camping behind me and he is a Jeep guy and said most likely it was the transfer case chain. He said that was fairly common and not a big issue until we were doing some decent wheeling. I didn't get a chance to take him for a ride before he left to get a "confirmation" of that.
I realize it is very hard to diagnose these things over the internet, but is that at least probable? I have driven it maybe 50 miles around the island over the last week and other than the noise, it is running great. The steering is tight and feels good. I ask, because the wife and kids are still down the beach, I needed to come home and work for a few days. I am hoping to avoid it being an issue on the ride back this weekend.
Sorry for the long post but I want to get an action plan together if need be. Thank you guys, for any and all input.