I've done my homework on replacing boots on these units with a Non zipper type. My question is i'm looking to maybe purchase a truck 200+ away. 2 of them are leaking. Do i need to worry about the bearings running dry? I'm a slow driver anyway so speed won't be a factor. Just didn't know if i needed to prepare with lots of duct tape and garbage bags and tubes of grease. Or does most of the grease stay in and the real concern is H2O and contaminants getting in ? I'm not even gonna attempt to use the zipper style from what i've read.