Ryanwehr14

Pretty much zero rust on the truck, the frame is super clean. Non-snowy area of California for its whole life. They didn't mention JB weld specifically, just a silicone style seal.

A while back, my truck (2018 GMC Sierra 1500 5.3) went in for an o2 sensor and routine service. The tech identified that my rear output seal on my transfer case was leaking, and recommended I have them replace it. At the time I didn't think anything of it, and had them do the repair. Less than a month later, I noticed that the recently repaired seal was leaking again. I called the shop that did the repair and they warrantied the repair and replaced the same seal again. A few months later, I noticed that once again the same seal leak had come back. It wasn't a great time to bring it in and I ended up just living with it for 6 months or so, noticing small (smaller than a baseball) size oil stains below the truck when it would sit for a while, as well as oil spray on the frame (to the point where it actually took the underbody coating off in that one spot). Finally got around to brining it in again, but this time I took it to a dealership service center since I am in a different part of the state for school. They identified the same output seal leaks and recommended they replace them. They also said there was no scoring on the inside of the transfer case, so it didn't need to be replaced. They chalked up the original repair failures to non oem seals and a job that wasn't done correctly. Now they called and said the seals are holding after driving/sitting for a while, but they found a very small leak in the middle, that they recommended they seal with some kind of silicone/jb weld (not sure what they are using). I haven't picked up the truck yet, but I have been reluctant about this whole repair process because I feel like they are just fixing the same thing that keeps coming back, and I am concerned there could be another root cause for the seal failing. Has anybody else experienced anything like this, or have any ideas on other things that could be the root cause?