After 20 years and 13k hours on the -400 I noticed that the after take-off autobrake system failed to operate on many occasions. This was evidenced by the vibration mentioned being felt even on the flight deck. My solution was a short application of the toe brakes which stopped it (and therefore the wheel rotation) within a couple of seconds. I always wrote the snag up on arrival at the next station for rectification. I don't know if this was an approved solution but it worked for me - if left to spin down unaided the ever diminishing vibration could last for a couple of minutes or so and caused some passengers alarm. If it was the nose wheel snubbers that were out of alignment then there was nothing to be done and you just had to sit and suffer until the wheels spun down.
To my amazement very few other pilots remarked on or even noticed the problem, which brings me to my bête-noir, those who stick so closely to the centre-line that they hit every centre-line light, on a 50 second take-off run this equates to hundreds of bangs, shakes and rattles. A foot or so either side and all is peaceful and quiet!