B2200 Long Bed Driveshaft Issue

Members: My 1989 B2200 Long Bed has a squeal coming from the driveshaft. It generally only occurs while the the vehicle is coasting or while in reverse - if you are on the gas, there is no noise - let off the throttle and the noise starts -except while in reverse, where it seems to always squeal. My problem is that it is coming from the area of the carrier bearing and universal joint in the middle of the drive shaft and I can't seem to determine which is the source of the noise. Any advise would be appreciated.

On a related note, why is the center u-joint on my truck not staked, while the ones at both ends are staked? Is this normal? Thanks in advance.

In my 1991 longbed I had a similar problem I just went to the salvage yard and got a complete assembly for 75.00. Problem solved.

The U-joints on the ends are staked because mazda didn't want them to be replaceable. To make them replacable pretty much you press them out, cut the stakes out, then find a replacable u-joint that fits. Most of your driveshaft shops do this very often.

The center U-joint is locked together with clips on the back side of the bearing cups. This one Mazda had to make replacable otherwise you could not take appart the driveshaft.

My guess would be the squeel is your carrier bearing, if it was the u-joint you would probably feel more of a vibration on acceleration or decel. To check mine I just unbolt it lower it down a little and spin it a few times to feel and hear how it sounds.