Rattling noise from transom

[victorc1]

I have a 1995 Mercruiser 3.0 LX with an Alphaone Gen II, when I am driving if I turn all the steering wheel all the way to whatever side or when I take off there is a rattling noise and the boat vibrates. When I take off, I have to play with the trim button and lift it up so that the noise and vibration doesn't feel so bad. I figured it was the u joints so I changed both of them and also took the gimbal bearing out and check it, it was still good. The problem still continues. Can somebody help me please?

 

[RandyJ]

Re: Rattling noise from transom

Are you sure it's in the transom and not the motor making a rattling noise? Timing issues and firing can cause a motor/valves to rattle. Changing the pitch of the outdrive will change the load on the engine which may change the sounds from the engine.

 

[victorc1]

Re: Rattling noise from transom

I rebuilt the motor resently, I also took the cover off the motor to see if the noise was coming from the motor but its not, it sounds stronger at the back of the boat near the top of the transom.

 

[fishinpa]

Re: Rattling noise from transom

If the joints where properly replaced and you still have the noise and vibration it appears that you prob should have changed out the gimbal bearing while you where in there , a lot of what you describe indicates a worn gimbal bearing.

knocking that bearing out too check it and pounding it back in is an easy way to make it worse if it was the problem .

im sure others will chime in on your problem here ...


fish

 

[tractoman]

Re: Rattling noise from transom

x2 on the bearing.

 

[achris]

Re: Rattling noise from transom

Most likely the bearing, but I have seen this problem with worn 'O' rings. The 'O' rings on the yoke are there to stop the yoke making hard contact with the inner race of the bearing. If they are worn and not stopping that contact, you'll get a vibration and rattling noise whenever the drive is anything but straight to the engine (steer left or right, trim up or down).

Chris......

 

[Don S]

Re: Rattling noise from transom

When you rebuilt the engine, did you remove the outdrive??? Did you do an alignment check after reinstalling the engine?

 

[victorc1]

Re: Rattling noise from transom

Didnot remove the outdrive and installed the motor exactly where it was on the mounts.

 

[achris]

Re: Rattling noise from transom

Didnot remove the outdrive and installed the motor exactly where it was on the mounts.

Bad idea.... You have probably done some damage to something.... Pull the drive and align it PROPERLY!

Why do people do that? It takes all of 10 minutes to remove the drive and you don't run the risk of any damage. And you spend another 2 minutes checking the alignment before the 10 minutes to put the drive back on. Total of 22 minutes to ensure you don't destroy the coupler/gimbal bearing/unis.

Now you'll have to remove the drive and the engine to replace your damaged coupler. Very clever.... You saved 22 minutes and now it will cost you the time to R & R the engine, again, and the cost of the new parts. Maybe this time you'll do it right and take the damn drive off LIKE THE BOOK TOLD YOU TO IN THE FIRST PLACE!

Grrrrrrrrrrrrrrrrrrr!!!

 

[victorc1]

Re: Rattling noise from transom

Okay calm down, how do you do theb alignment check?

 

[achris]

Re: Rattling noise from transom

Do you have the service manual? If not, then download it HERE.... It's all in there (page 2A-11).

 

[RandyJ]

Re: Rattling noise from transom

Don't get too overly concerned but do check the alignment. It's easy. The pro's will tell you that you need an alignment tool. I made one out of a pipe that snuggly fit inside the coupler. I know guys who've been marine mechanics for lots of years who juld st eyeball it. The big trick is that the driveshaft should very easily slide into the coupler. You should feel a bump when the o'rings on the shaft meet the gimbal bearing... a little bump or shove and it goes right in. If you want to invest in an alignment tool that's a great idea too for extra insurance and peace of mind.

 

[victorc1]

Re: Rattling noise from transom

Okay thanks, I'll keep in touch to let you know how things went.

 

[victorc1]

Re: Rattling noise from transom

Okay so I went to align the motor and I found water in the bellow, the clamp was loose and water was seeping in, which by the way explains why I always was getting water in the bilge. I changed the gimbal grease seal, bearing and greased the u joints, which also had water in them. (I know I'm going to have to change them again). I also tighten the clamp and had the propeller fixed because a few times I had bottomed out on sand. I started the motor up with the hose connected to the ears and now there is a rattling noise coming from the middle or bottom of the drive. Its probably when I bottomed out. What do I need to fix in the drive now?

 

[dubs283]

Re: Rattling noise from transom

first off, start a new thread about the drive noise

then explain whats happening (in the new thread)

 

[EddiePetty]

Re: Rattling noise from transom

....."and now there is a rattling noise coming from the middle or bottom of the drive."

And before you start that new thread:

While the engine is running (on muffs) in neutral, place your hand on the bullet housing of the propeller shaft and see if you can feel the rattle. If so, briskly shift the drive to forward/neutral/reverse/neutral and see if the rattle either changes pitch or disappears. Your clutch dogs my not be disengaging completely. A minor cable adjustment, at least, and a lower shift cable replacement, at moderate most, should correct this.

 

[cr2k]

Re: Rattling noise from transom

Shortcuts only get you back together faster to find out there are things you should have done right to begin with.

 

[EddiePetty]

Re: Rattling noise from transom

Shortcuts only get you back together faster to find out there are things you should have done right to begin with.

So where is the shortcut??

The OP stated that he has replaced the gimble and accessories and now a new problem has arisen.

YOU ever hear of trouble shooting or problem isolation?