When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Bull....if shifting on the fly would mess up your 4WD system then Ford would not recommend it...think about what you are saying.
ford recomends alot of things when ther cars and trucks are new, then they get driven, a ton of a warranty work get paid for by them, and then they alter service procedures. just because it's in a 10 yr old owner's manual don't mean it's right.
I heard the same thing from a ford dealership, switching to 4hi at 50mph or less a lot will wear out and mess up the front diff a lot faster. Only switch at a roll if you absolutely have to..
did you mean 50 or more?? the biggest thing that will cause wear is if you throw that switch when you have a foot full of throttle