Good to know. You seem like someone who actually knows what they are talking about in regard to this issue. I do have to say that I have gathered from your previous posts that there is not a lot of warning of impending failure though. Things like you won't see small cracks, you are going to see grease flung about and an actual hole in the boot. I am worried that I maybe stop at a gas station, check the boot and it looks fine, and 200 miles later driving at 83 mph this thing grenades. Maybe I have misunderstood some of your previous posts. Thank you
Boot failure and catastrophic failure are two different things. There are two failure modes to be concerned about, boot failure and clip failure. I have had both on my truck. Boot failure ultimately ends in potential fire. And clip failure can possibly end with mechanical damage to transfer case or transmission.
Boot failure is the predominant failure, it starts with a tear in the boot, then grease leaves the chat. At that point you are on borrowed time as the joint starts cooking itself if you keep operating at high speeds. But if you are driving say sub 50mph then the joint may last forever in relative terms. I would confidently and have for that matter driven on a torn boot for hundreds of miles at lower non highways speeds. I would not consider highway unless it was a short exit to exit run.
A clip failure is virtually impossible to spot pre failure. You can only feel for this or tear down the joint to inspect. You would have to fairly aggressively putt on the back half of the shaft trying to pull the shaft out of the joint. If it gives at all your clip failed. But this assumes full failure. I personally had a partial failure that would not have shown without tearing down the joint.
To prevent a clip failure your only solution is to change the clip prior to setting off regardless of mileage on the clip.
To prevent a boot failure you should change the boot or whole joint about every 7-10k miles. So if you're taking off on a 2k mi journey and you have 5k miles on your current joint/boot I would highly consider swapping the boot and joint. You can keep the part you replaced as an emergency spare, it's still good.
Hopefully that all makes sense, neither would keep me from taking a trip, I would just check the assembly at every fueling stop and be vigilant about any tone changes or minor vibrations that don't feel normal.