2006 Honda CR-V shaking in 4, 5th gear at lower rpms

I’m the sole owner of this 2006 Honda CR-V manual transmission. Over the past year or so I’ve noticed a problem that is gradually increasing in severity. In 4th and 5th gear, I can get a lateral shake in the vehicle during acceleration under lower rpm acceleration (or trying to keep speed going up hills) I don’t notice it in 1st or 2nd but my wife notices it in 3rd. She was the main driver until 1 1/2 years ago. We mostly drove it in our small town, some 25 mi commutes through rural 55 mph roads and long distance vacation drives. I use it almost exclusively for the commute now. In it’s first few months in 2006 the front tires would bind up while turning into a parking spot. Kind of like a 4WD truck on dry pavement. The dealer said there was notice out to replace the trans oil to fix the problem. Apparently there were shavings in the trans oil?? At any rate it fixed the problem. That is the only issue/work done outside of regularly schedule maint. The shaking is getting worse over time and will almost shake water out of a glass in the console if I put the pedal to the floor at 55 mph 2700 rpm in 5th gear. The steering wheel does not shake and I could take my hands off of it and the car would track straight. But I would never take my hands off the wheel, or at least admit it ; ) If I accelerate from 55-65 ever so gradually I can do it without the car shaking. The larger the torque in this rpm and speed range the more severe the shake. In 4th gear it’s the same rpms and slightly different speeds to get the same results. A mechanic told me a couple months ago that it was an axle in the rear and it was safe to drive. Let the problem get worse to make sure it’s an axle or bearing and then we can identify the problem was his advice. Any thoughts? I’m worried it’s a trans issue. I’ve had a bad bearing on VW and cv joint on a Honda before. This doesn’t act like that. Plus, this is essentially a front wheel drive car with rear engaging only when front wheels continuously slip. I did have a Isuzu Trooper that needed a front right axle after a mechanic failed to secure the pins to engage 4WD after a brake pad job and it chewed up the axle. Could it be something like that? Puzzled.

How could it be an axle in the rear, as your mechanic said? The rear axles are not being driven except when the front wheels are slipping and the AWD is kicking in automatically.

It sounds to me like a bad front axle, since you say you can make the shaking more severe by torquing the drivetrain.

Some friends suggested that a rear axle/end problem presents in a lateral shaking of the car, or an in the seat type of shake and a front end issue would be noticed in the steering column. I have the in seat shake and the steering column is fine. Is there anything credible to that argument? I totally agree tho, how can a rear axle that is not engaged in the drive train even cause a rattle/shake?

I don’t believe it’s a rear axle because you’ve proven you can change the nature of the vibration depending on how hard you torque the engine, which is driving only the front axles and wheels (when AWD is not engaging).

Yes, you can have a front axle vibration that is not felt in the steering.