Thanks for welcome and the feedback folks.
My RTV has a curved metal shield bolted to the front of the A-arm. You can see it in the picture. My boot didn't get ripped by a stick, it failed, after 10 years and 1,977 hours, in what looks like a perfectly circumferential fatigue failure at the point of maximum flex stress when the wheels are turned. If the wheel is straight you can't tell it's damaged. It just pulls apart when the wheel is turned.
I put my fingers into the grease that's exposed in the picture. It has no grit in it. No evidence of dirt, so hopefully I've dodged a bullet.
The plan is to replace both boots on both front CV joints (drive shafts?).
There is no way I'd use that split boot. This repair is easy enough that I can't see any reason not to do the very best job possible. That split boot just doesn't look as good to me as the one piece that's lasted 10 years - this time anyway.
I cleared out the wood shop to make room, backed in and put it up with 4x4 under the rear wheels and jack stands under the frame.
I'll take it apart tomorrow and get things ready for when the boot kits arrive.
I'll drain and replace the oil in the knuckles and front differential while I'm at it.
Fitch
oooh Greenwannabe I guess we got what we asked for. 
collie
