I have a 2004 dually and a 14,000 lb fifth wheel camper and 4 low is the perfect speed for backing up smoothly! But when I'm on pavement, I cant use it. I remember reading in past issues about a 4 wheel drive low switch. Some way to put truck in 4 low and electrically keep hubs from locking in. But after some investigation, I cant do that on this year. Is this correct? I found some lock out hub assemblies from Dynatrac Engineering and waiting on pricing. Anybody have any information, referrals, or ideas for this dilemma?