Possible passenger side axle problem. See if the shop you've been dealing with for the other parts replacement will put it on a lift and watch the axles if the symptom is able to be duplicated on the lift then you'll have it figured out.I would suggest have the tech who will be in it on the lift , go out and test drive with you to know how to duplicate the vibration on the lift. If it needs to be under slight load then he'll have to ride the brakes carefully to duplicate. If it's strictly speed sensitve then hit 65MPH on the lift and you will have your answer.
My local garage tried to duplicate the problem on the lift, but couldn't. They put the car in gear and ran it while it was on the lift. They didn't see anything wrong with the axle shafts. The tech said that since the suspension was drooping down (not supporting weight of the car) that it wasn't the best way to check for the problem, but it was worth a try. Everyone seems convinced that vibration is coming from the front end...
New information: I replaced the front engine mount because I knew it was bad (others look OK). The vibration is now better, but it's still there. Now vibration starts at about 68 MPH (was 60 mph).
Due to process of elimination, I now strongly suspect a bad CV shaft, but they both appear OK. No clicking noise when turning and no noticible issues when moving them in and out towards transmission.
Sounds like they are trying ! Just for info. sake , inboard joints typically do not make noises , especially not the 'knuckle popping' sound the outboards make when bad. Inboards can be difficult to prove. I work at a honda dealership now , and the cases Ive seen that match your description have been on the Odyssey and pilot model , both have a two piece shaft on the pass. side. Yours is similar , that is why I'm leaning towards that one in particular. Just curious , do you know if they applied the brakes & at the same time maintain speed to duplicate the 'load' condition while on the road. That can be tricky and some would be hesitant for fear of over-heating the brakes , so it has to be quick.If I think of anything else I'll reply again. Good luck.
New development- The other day I accelerated (pedal to the floor) up a long steep hill on the highway. Once I got up to speed, I noticed the vibration was gone! However, after I got off the highway and stopped, the vibration returned when I got up to ~ 65 MPH.
Poss. re-check all mounts for correct positioning. Question not asked before....has vehicle had ANY type of collision repairs done to it? Just a thought , as far as proper 'powertrain' alignment goes.Hard accelleration up a steep hill? See if you get the same result (albeit temporary) twice and definitely inform the shop.