Hi Scotty, I personally owns a 2005 Honda Odyssey doing 170000 km on it and owned it just about 2 years now. I alway had a shudder/vibration at highway speed sometimes more than others. I have taken it to a mechanic that did road force wheel balancing, did Front brakes and rotors,struts/springs (front) and everything they said are fine in front and the vibration is still the same. Now they said the only thing left that can cause this is the axles ! Can you please advise me on this and have you came across this with these vehicles before. Thank You and much appreciate your expertise .

more often it's internal transmission damage causing that , a known flaw on that model. Have a tranny man check that, and if so, get rid or it or spend countless thousands rebuilding it