View Full Version : Terrible Vibrations

02-28-2008, 02:03 PM
I have an 2007 Outback with 18 hours on it. Was out yesterday and the boat began to vibrate really bad. I shut it down and started again. At 1800 RPM's is when it began to vibrate. So I limped into the marina. The dealer is coming out to figure out what is wrong. I am looking for your ideas before hand. Thanks.

02-28-2008, 02:48 PM
Could be a number of things. Let the dealer do his stuff, esp. if boat is still under warranty.

02-28-2008, 03:34 PM
Usually when a boat does that the prop hit something and is now out of balance! You can just bend the tip of one blade about 1/2 an inch and that is all it takes! Been there and done that a few times!!! Stupid stumps!!!!

02-28-2008, 07:48 PM
Same thing happened to us last summer in our 07 Outback. Was a bent prop all the way. These Nibral props don't like to even be looked at funny :D

02-28-2008, 10:08 PM
I had the same problem when I hit a stump last summer too. You could not even see the bend with the naked eye. Those things are sensitive. :shock:

02-28-2008, 10:50 PM
You got that right Seark

02-28-2008, 11:24 PM
I personally prefer the prop to be the weak link cuz it's the cheapest to replace. If you've got a rock solid prop then your shaft would be the weakest link. I'll take the bent prop anyday.

02-28-2008, 11:47 PM
You can isolate the problem a few ways. First, you say this happens at 1800 rpm. Have you put the boat is neutral and revved the engine to see if the vibes are still there. This can isolate an engine problem from a prop or shaft issue. If the motor is fine without the shaft engaged, then the problem is probably the prop (as state in other posts), maybe the shaft, or possibly the transmission.

02-29-2008, 12:01 AM
Thats a great way to diagnose the problem! Problem is the guy hasn't returned to the posts!

02-29-2008, 01:21 PM
Thanks eveyone for your imput. I did power only the engine and that seems to be fine. So we seem to have it isolated to the transmission, shaft, or prop. I met the mechanic out on the lake today and he has some ideas, but wont commit until he gets it back to the shop. I will post something once I have more info. Thanks again for the input. It has been very helpful.

03-10-2008, 01:01 PM
I got my boat back and wanted to thank everyone again for there feedback.

The cause of the problem was a loose bracket where the transmission and engine connect. Besides the vibrations it also caused the transmission seal to leak.

Thanks again.

03-10-2008, 01:08 PM
Hopefully, all is well now.
I have found boats have certain notorious areas that need watched and tightened periodically. Swim platform screws and mounts, tower mounts, cleats, hose clamps, just to name a few.
Part of my de-winterizing includes checking those and more.
Hope this helps

03-11-2008, 12:00 AM
I hope they really checked this problem out very well. A leaking transmission seal!? If the engine and transmission were not in alignment then you would have also put some undo wear in the input shaft bearing in the transmission! I kind of find it hard to believe that just one bracket could cause this to happen. There are several bolts that hold the transmission housing to the block, were they all loose too? The chances of that happening are close to nill unless the production worker who installed the transmission to the engine just happen to put the bolts in by hand and then took his lunch and forgot to tighten them when he returned. I could see where the engine and transmission were not secured to the boat would cause this problem. I would have to really question the dealer on what repairs were actually made on this one.

03-11-2008, 11:58 PM
Z has point there, although again I doubt we have the complete story as to the diagnoses and remedy.

Glad to hear your back on the water down time is never any fun 8)

Sorry about the spelling, kind of tired

03-14-2008, 04:25 PM
Thanks for the great advice. I am sitting down with the lead mechanic and service manager on Monday to get the full story.

04-24-2008, 10:55 AM
Do the Moombas bolt the motors down or lag screw...someone told me they screw down the mounts....seems unlikely.