A rough idle and harsh transmission shift can be caused by a broken front engine mount. Replacing the broken mount will address these issues.
Car Problem Reports
Honda Odyssey Rough Idle/Harsh Shifting Due to Broken Front Engine Mount
Honda Odyssey Problem
Engine Affected: 3.5L V6
Average Mileage: 129,000 mi (67,000 mi - 180,000 mi)
Needed all mounts replaced.
my front motor mount is stretched lot of movement i thought noise was coming from wheels goint to have replaced
Visitor, 2004 Honda Odyssey, 3.5L V6, 108,000 mi
mildly rough idle. routine check during an oil change at the dealers, brought the broken engine mounts to our attention.
Visitor, 2003 Honda Odyssey, 3.5L V6, 130,000 mi
Had to replace rear and side engine mounts
Visitor, 2004 Honda Odyssey, 3.5L V6, 104,000 mi
Replace the right motor mount and that fix the problem.
Visitor, 2003 Honda Odyssey, 3.5L V6, 67,000 mi
Car kept clunking it got worse so I took it to the dealer and they said it was a broken engine mount. Got it fixed and now it is just fine.
Car idles and starts rough after front engine mount replaced.
Visitor, 2004 Honda Odyssey, 3.5L V6, 148,000 mi
had to have my front motor mount replaced. shifts much better, but now it idles rough. can never win!