I changed out several things in my 1999 Honda Accord a few weeks ago. 

- the water pump, timing belt, balancing belt. 
- left front axle (CV boot torn)

- left lower ball joint. 

Everything seems to work fine. But there is a slight vibration I can feel in the steering wheel. Very very slight. It’s ever so slight, maybe it was there before and I didn’t notice it.  Or maybe this repair caused it. 

It only appears during higher freeway cruising speeds. But it’s not consistent. 

Not sure if it is true same problem, but I also hear a rotational pulsing sound also at freeway cruising speeds. Also not consistent. 

I don’t think it is the engine, water pump, timing belts, balancing belt, because when I engage the clutch to disengage the engine, the sound still continues. 

I highly doubt it is the ball joint. 

Could it be a bad axle?  I got a Cardone branded refurb.

Or maybe a bad alignment job?

Or could it be something else?  What else could cause the vibration and pulsating sound, respectively.