Ok recently purchased a 1994 Grand Cherokee with the V8 with the NP249 transfer case with 100K on it. Runs great aside when turning in parking lots, driveways etc. its the front right side seems to want to hop and sounds like it's the viscous coupler from everything I've read. But looking at the tires three tires are michelin 235/75R15, the front right tire is a 225/75R15 Goodyear with horrible cupping on it. Could the problem be just the tire size difference? Or as I fear the coupler is smoked?
Yes, your problem is the different size tire, and most likely it has burned the VC. With the 249 you MUST have same size tires, and adjust the PSI so that the actual diameter is very close the same between front and rear.
Either replace the coupler or case. A bad coupler will just start wearing out the new tires. Besides, if you replace the coupler you will need 5 new tires all the same. The 93-95 249 is more picky about that. If you have mismatched tires or tires with more tread than the others then it will wear out the VC faster. It's power is split 50/50. Later years like 96+ are like 10/90. Basically RWD until the tires slip.
If you have limited funds, if you can find a 242 at a jy and are handy that will be a 1 expense. You do risk damage to your front diff if you continue on 2 different sized tires. Depending on where you are you can find cheap used tires. Hell I have 4 sitting in my garage I can't find someone to buy.
Ummmm....im confused. Correct me if im wrong, but only the 96-98 249's have VC's. And the 93-96 have more like a clutch pack. So if you are experiencing wheel hop/bind start with the tire and also check the u-joint/CV-joint on that side.