Transmission Fluid Leak

I have a 1996 jeep cherokee 2wd that has leaked trans fluid since I bought it new in 1996. Actually it didn't start leaking until I had driven it about 15,000 miles. The dealer replaced the tail-piece seal and it quit leaking for about 10,000 more miles, then began leaking again. I have had transmission shops tell me I needed a bushing and seal, which I have had replaced two times. One transmission shop told me the stock bushing was rubber and they were going to replace with a bronze bushing and that would completely solve the problem. I don't know what they did but it began leaking again after about 10,000 miles. I have replaced the seal the last two times, but 10,000 miles is the most I get from a seal change. What is causing this? One guy told me that some of the tail pieces were defective and I needed to replace that. It now has 113,000 miles and is leaking a lot (probably been 20,000 miles) What should I do? Just plan to replace the seal frequently? Is there any benefit to changing the bushing as well? If so, what is the procedure for replacing the bushing?

You have replaced the seal numerious times, but have you ever looked at the input side of the DS that goes into the tranny? Most of the time the seal will get ate up by the slightest burr on the DS. Look were the seal "rides" on the shaft and see if there is any rust or damage to it. Rust can usually get taken off with a lite emory cloth or the green scrub pads. The surface MUST be clean an free of any defect for the seal to last. I have the same problem on my 88 XJ, the pinion shaft has rust on it, eventually tearing up the seal.

The last time I replaced the seal, I did look at the drive shaft and it looked clean and smooth. It's been a while, so I will check it again. Did you change just the seal or both seal and bushing?

I had the front axle pinion seal changed at the dealer, they just replaced the seal, never cleaned up the yoke, so it leaked eventually.