I have a 98 4door LT with 3-button switch on dash. When in 4wd (hi or lo) every few revolutions of the tires theres this loud crashing sound coming from the differential area (quieter on pavement/ louder on mud), also the front wheels stop pulling for a split second right before the crashing sound. obviously the 4-wheel drive is slipping, but i just did thrust washers, both front axles, both front hub bearings, new vacuum switch, and checked the diaphragm under the battery and all was good....any suggestions?

 

Dont drive it like this in 4x4 obviously, this happened to me it seemed like it only happened with the wheels turned to either side, but I didnt keep it in 4x4 long enough to find out, I had to replace the transfer case was $100 with extended warrenty and my cousin put it in for $200 I did u-joints at the same time since the driveshafts need to come off. Good idea if thats what it is. Let us know!