Towed for the first time with the truck and noticed when I manually shifted it from 2nd to 3rd I noticed a 500 rpm increase in between shifts. Didn't feel like trans was slipping because I felt it when it hit third. So on my way to work I tried the same thing from 2nd - 3rd and got the same thing. I did try this with the OD off. The truck was at normal operation temp. and it shift fine when you leave it in drive. This only occurs when manually shifting. Has anyone else had this occur? Do you think it is anything to worry about? My problem is I will be tt in the maintain allot and will probably need to be manually shifting once and a while. Thanks in advance for your in put.