bravo two outdrive knocking sound help

[bolo78910]

hello guys, yesterday i notice a knocking sound coming from my bravo 2 drive when gear , i can hear it up to about 2500 rmp, above that the engine noise overcome the knock. if i hit the trim button up or down the noise will stop antil i let go off the swich. i lost no power the boat still runs great. could it be a gear knock ,or a u joint knock. thanks god bles.

 

[tpenfield]

I would check the gimbal bearing as a first choice, then u-joints.

 

[bolo78910]

thanks much . gimbal bearing was new four month ago , maybe it the u joint bec when i bought the boat the lower unit had hit an underwater object