57 Merc w bravo 1

"I have a 2002 5.7 with B1 dri

"I have a 2002 5.7 with B1 drive. Total hours 165. Bought the boat last year and toward the end of the season noticed that when running at idle in neutral there is a random knocking noise eminating from the engine coupler/top of drive area. I do know that the boat was driven in shallow water with the drive up, sometimes up far enough to have it in "trailer" mode. I also have read that this is not a good practice at all. At any rate, the noise is less pronounced when in drive. What is the easiest way to assess what needs to be replaced. My guess is the universals and potentially the coupler have been damaged? Gimbal??"

"right track, u-joints, gimbal

"right track, u-joints, gimbal, yea the coupler can get damaged if run unchecked."

"okay, now I am trying to deci

"okay, now I am trying to decide how to narrow things down, rather than doing all three and not knowing if they are all necessary. Would the easiest and most likely place to start be the u-joint replacment? I have the manual from bondo's post and that looks to be fairly straight forward?"

Once you pull the OD the gimba

Once you pull the OD the gimbal bearing can be inspected along with the coupler and then U-joints. Turn the bearing with your fingers; it should be smooth and quiet. The splines on the coupler should look like the reverse of the OD drive shaft. If they are rounded or pointed then the coupler needs replaced. Uneven wear indicates the engine is out of alignment. U-joints should be tight and smooth feeling when turned. Grease them if they have fittings w/white lithium grease and look for rusty or gritty fluid.

"Thanks for the feedback Guy.

"Thanks for the feedback Guy. Kind of a bummer that I have to pull the OD to grease/check the universals? Seems like a lot of work for something that should be faily routine maintenance. Not debating it, just venting."

Yours may be unserviceable; se

Yours may be unserviceable; sealed.

"Yeah I kinda figured that fro

"Yeah I kinda figured that from what I have read. That doesn't bother me because if I go through the hassle of pulling the drive, they are getting replaced--cheap insurance in my mind. What I haven't been able to find is how to inspect/test the gimbal for issues?"