My wife drives a 1997 CR-V, 4WD, 96K miles. I drove it last week and noticed that the tranny does not seem to be locking up in 4th gear. Usually, after the reannny shifts into 4th, revs drop once again when the torque converter locks up. Lataely, this has become a problem in that sometimes it locks up, sometimes it just won't. Anyone have this problem, and what to do?