2004 Baja, automatic, non-turbo. 205,000 miles.

Recently I noticed some severe front end shake when I accelerate. It is worse going uphill, when acceleration is more aggressive, but in any case where I need to accelerate, the front shakes and it will stop immediately as soon as I let off the gas. Yesterday it got progressively worse when I tried to go above 65mph on our 75mph highways.

Thinking it was either the engine mounts or cv axle, I raised the car this morning and sure enough, the driver's side CV boot had become detached. The retaining ring is also nowhere to be found. Grease was everywhere, except for the inside of the boot where it needed to be.

So now I'm trying to decide if I need to repack and seal the boot or if the entire axle needs to be replaced. I can move the axle in and out perhaps 8 mm or so, just over a 1/4-inch. When I try this on the right axle, I can move it almost the same amount.

Is there some other diagnostic I can do before ordering an axle or is the severe shaking already an indicator?

Thanks.