Hi, this is Sweet. I had my brother change the front motor mount on my 99 accord 4 door 3.0 V-6. The car needed it because shifting was making so much vibration, on both drive and reverse. We first changed the top one on the passenger side, which is easy to replace and SOOOOO worn out. I checked out the car. Now when I put it in reverse she is SOOOOO smooth. But when I put it in drive it still has this harsh push or jump. I looked at the front by the radiator, it looks Ok, How can I tell if it's the back one?

 

A quick way to test is to try and push/pull on the engine to see if there is any excessive movement coming from that rear mount. Also look to see if there is play in the transmission mount.

 

Have some one power braking the engine in either direction and you look for engine lift.