Mine doesn’t have a boot either. I keep a good supply of grease there. It’s been a few years now, and the slip joint is still tight and we all know what kind of slop I subject my rig to. I’d say unnecessary if you do basic maintenance
I really appreciate it and thanks for confirming! They do have a small seal there but not the boot. I'll run the boot on the front. I am hopeful this thing will be driving tonight or tomorrow.