Rumbling Noise 1999 2100 SR 5.0L Alpha 1 - Maxum Boat Owners Club

azmax · 03-09-2008, 01:48 AM

Well after the prop mixup, we went back out to the lake on Friday, and the boat performed well. Good hole, shot, RPM's right where they should be. Ran for about 20 minutes at about 3000 RPM, with no problems. When I returned to idle I heard a rumbling noise from the engine compartment. I put the boat in forward and reverse, still same rumbling noise. I just had the impeller replaced and lower unit serviced. Temp is fine, oil pressure fine, no alarms. Any ideas would be helpful. Cheaper one's are always welcome!

seapuppy · 03-09-2008, 03:07 AM

could be the coupler..or the u-joints......I'd think more on the u-joint side....

azmax · 03-10-2008, 04:30 AM

Thanks. Noise occurs in both neutral, forward and reverse. Do u joints rotate when in neutral. Sorry for dumb question. I am stern-drive illiterate.

seapuppy · 03-10-2008, 01:05 PM

yep....

Mad Max · 03-11-2008, 08:43 PM

Last season I had to replace the 'spindle' bearing and u-joint coupler (along with new seals and boot). Seems that the seals leaked water into the boot, allowing the bearing to rust. This created quite a 'rumble' and vibration. It 'revealed' itself at about 3000 rpm as I pulled away from the 'no wake' zone. After I limped back to the dock and re-trailered, took it to shop.

You can get parts yourself but I would recommend a good shop do the work (warranted).

Good luck.