2008 GV Drivetrain question (Issues)

[gvedmonton]

I have had this GV for about 25k klm right now, when it was at about 10k i started to complain about a vibration or "bumpy" feeling to it even while driving on very smooth roads, they did the alignment thing for me and then proceeded to tell me that it was all in my head and maybe i was to sensitive to the road feedback through the steering wheel. The viration always seemed to start at around 60kph all the way up, one trip when placing it in passing gear it shook like crazy, yet they continue to say it was all about me, nothing wrong. This past weekend i was hauling my boat (about 1000 lbs) out of the lake on an older boat launch, it got wet and groovy so for the first time i placed it in 4L Lock, and thankfully it pulled that sucker right out, when i was done i did the neutral and brake on to place it back up into 4H i hear the piston (or whatever it is) disengage and off i went. Now here i notice a difference, while driving it the truck had easier get up, did not "engine break" like it did before and is much smoother , the vibration seems to but gone and so has the bumping. Is it possible that this thing was locked in a gear somewhere for 15,000 klm? can the vehicle drive at hi-way speeds without revving the crap out of it while in a lower 4 wheel gear? something is odd about this, i am afraid there is something wrong somewhere but unless "I" can figure it out no one seems to want to listen at the dealership, they would not even put on a hoist or anything. I have a call into Suzuki Canada (4 days ago) and still no call back from them. If anyone has any insight at all that might hell me out i would really appreciate it.

Mike