Update. I had 2 leaks on my T Case: The front output seal, and the O-Ring on the actuator. The front output seal was much more work than the O-Ring.
I ordered 3 of these Shaft Oil Seals TC15x23x7 in the event it is still leaking after just replacing the O-Ring, but so far so good in that regard.
To get the actuator off the shaft, I followed the instructions in this thread and turned it counter clockwise and gently pulled it off. No popping or breaking noises were heard, but it didn't just slide off, it took some wiggling and gentle pressure. Putting it on was a bit more work. I tried holding the shift pin out of the Tcase as far as I could, then gently pushed the actuator back on. It took about 5 frustrating minutes, putting the spring back on the seal twice, before it finally went back on. Again, no popping or breaking sounds, just gentle wiggling and pushing.
I bolted everything back together and took it for a test drive. The CDL activated just as it had in the past, and I still have High and Low range.
Reading through the threads, I decided the risk of about $6 in parts ($2 for the seal which I haven't installed, and $4 for the O-Ring) was worth trying. If I screwed up the actuator, I can go without CDL for a while and it would be more than $1k if I took it to a shop for them to drop the case and replace the seal as stated in the repair manual. So the risk to me was worth it to try. Worst case I would be looking for a used Tcase or looking at upgrades.
I ordered 3 of these Shaft Oil Seals TC15x23x7 in the event it is still leaking after just replacing the O-Ring, but so far so good in that regard.
To get the actuator off the shaft, I followed the instructions in this thread and turned it counter clockwise and gently pulled it off. No popping or breaking noises were heard, but it didn't just slide off, it took some wiggling and gentle pressure. Putting it on was a bit more work. I tried holding the shift pin out of the Tcase as far as I could, then gently pushed the actuator back on. It took about 5 frustrating minutes, putting the spring back on the seal twice, before it finally went back on. Again, no popping or breaking sounds, just gentle wiggling and pushing.
I bolted everything back together and took it for a test drive. The CDL activated just as it had in the past, and I still have High and Low range.
Reading through the threads, I decided the risk of about $6 in parts ($2 for the seal which I haven't installed, and $4 for the O-Ring) was worth trying. If I screwed up the actuator, I can go without CDL for a while and it would be more than $1k if I took it to a shop for them to drop the case and replace the seal as stated in the repair manual. So the risk to me was worth it to try. Worst case I would be looking for a used Tcase or looking at upgrades.