Center bearing

Is any 'play' acceptable in the center bearing. If I push up on the drive shaft of my 1999 Prerunner, it moves about 1/8th to 1/4". Is this acceptable?
I am hearing a noise when coasting and it disappears if I accelerate.
I've greased all the U joints but still get the noise. Rear end has been serviced and checked by a dealer. I didn't notice the center bearing play until now.

My 2004 shop manual doesn't specify how much play is acceptable. It reads,"Check that the bearing turns freely. If the bearing is damaged, worn, or does not turn freely, replace it."

With 1/8" to 1/4" play I would consider the bearing is worn and should be replaced. Otherwise your driveshaft and it's components will eventually be damaged because the worn center bearing allows it vibrate and whip.

Clifton

If the specs say that it should turn freely and not be damaged or worn, then I agree that it should be replaced. Bearings in general have very tight tolerances. Your clearances in the bearing are much greater than normal. When you replace it, you will see how much less play you have in the new bearing.

Here is a solution for the center bearing you may want to think about. I understand replacement bearings are expensive. A good driveline shop can build driveshafts to your specification.
http://www.4x4wire.com/toyota/tech/driveshaft/

You also may want to read this Driveline basics article, the angles of the driveshaft in relation to the transmission and differential are critical for reducing vibration and wear. If your vehicle has been lifted the angles should be checked and adjusted as needed.
http://www.4x4wire.com/toyota/tech/driveline/

Clifton