dedbrk

Hi all,

I'm in need of some advice that will let me sleep decent through the night. I just bought a new boat (very nice to me) that has been in the water 2 times in 3 years. It has had very good maintenance and has 204 hours on it. After a good check of fluids and warm up procedure on the hose in the driveway (new impeller) I thought she was ready for a sea trial. Left the dock on a slow idle watching all of the gauges for 10 minutes or so. Throttled up on a plan and let her run at 30 MPH while continuing to watch the vitals. I didn't make it a 1/4 mile and I started to smell smoke similar to burnt rubber or grease. Throttled back off a plane, shifted it in neutral and raised the engine hatch. As the hatch was going up a large amount of smoke was coming out of the engine compartment. Shut the engine off and floated for a bit trying to determine the cause. Pretty sure I shed a few tears at this point too I could tell the smoke was from the back of the engine area and while the boat was off I could hear a crackling sound from the input shaft area. Similar to grease crackling on a hot object. Started it back up to head for home and noticed a vibration had accured from this point on. Never smoked again on the way back to the dock but the vibration/growling sound stayed with it in all gears and in neutral. I've looked at the coupler and it doesn't seem to have shredded rubber anywhere nor does it look like it got hot at any point and the splines look fine from the outside. We are going to pull the drive this weekend in hopes that it is the gimbal bearing. Has anyone ever heard of a gimbal bearing doing this? My main goal is to be somewhat certain that it's the gimbal and not the long process of pulling the engine should it be a coupler. It's a 502 Mag with Bravo One drive. I appreciate any advice given because I know there are many experienced people on this forum I can turn to and most of them have had their hearts drop when a similar situation has happened to them

Thanks,

Sunshadow

sounds like either the gimbal or a ujoint. sounds like it sat quite a bit. I've seen nearly new bearings go bad from sitting. a little water/condensation and a little time they can grow a little rust.

tms1155

Gimbal bearing or u-joints for the growling noise but neither of those will give you smoke. burnt smell and smoke is the coupler.engine may be out of alignment causing all of above.

dedbrk

Is there a chance that the gimbal froze up and got hot enough to cook all of the grease making the smoke described? There's just two things that don't add up to me. 1) The crackling sound (almost like a cooking bacon sound but slower crackles) coming from the input shaft area after the boat was off for a while. 2) No small rubber pieces in the hull or signs of coupler getting hot when looking at it. Another thought, I lost no propulsion when the smoke hit or when driving back to the dock. I've heard if you smoke a coupler it's similar to a transmission slip. I guess I'm just trying to live the pipe dream and hope it's not the coupler. I will keep you updated as we tear it further apart. I'm a glass full kind of guy so I still have hope since a few people think it could be the u-joint/gimbal. Thanks for the replys so far.

nards444

Well growling specially when you turn is probably the gimbal, needs grease or replaced, and sometimes they just growl. was the boat stored before you bought it because people store engines in a million different way, they fog the carbs, put a cap full of oil on top of pistons, WD-40 things to prevent rust, or just flat out lube the hell out of. Let it run in your driveway and watch it, double check all fluids and grease nipples. I mean if the boat sat for three years, its probably going to burn off some crap and vibrate and growl a little bit

nards444

Oh and grease the prop shaft and anything else that has a grease zook on the lower unit

dedbrk

It definitely growls when you turn it. When running on the hose in the driveway in neutral it growls the most with the outdrive straight forward. If you turn it hard to the left it goes away completely and hard to the right makes it growl about the same as straight forward. The growling goes from very noticeable to completely quiet depending on the outdrive direction. Haven't seen what it does tilted up or down because by this point I knew something bad was happening and didn't want to run it longer than absolutely needed in fear of making things worse.

dedbrk

OK I have another problem. Either the bearing is welded on the input shaft, rusted on the shaft or the coupler is binding it on. The outdrive will not break loose and pull out. Any suggestions?

jeff32

worst case: open up the top of the drive, loosen the nut so you can take the drive shaft out of the drive, pull the engine out with the drive shaft stuck in the coupler, and go from there...

that is only if it does not (the drive) pull out!

tms1155

Driveshaft will not pull out with engine, it will not pass gimbal bearing.