possible lower unit???

[JosephPC]

So I have a 5.0 mpi bravo 3 making noise. I thought it would be the gimbal bearing or u joints. You don't hear it at all when the motor is running turned in either direction but you do hear it when in gear. I know the shaft spins all the time and figured it needed a load in order to make noise so I replaced the bearing and u joints because the boat is 10 years old and I figured why not. The previous owner claimed he maintained it but by the looks of the wiring he did I kinda doubt it. I got the motor aligned until there were marks on all sides but the mounts are all the way up to the top up front and the marks were just a little harder to the bottom. The alignment tool went in fairly easy and turned OK but the drive was slightly more difficult to get in. I started it on the trailer and everything sounds good so I turned it side to side to see if it made noise. Still good so I put it in gear and I get noise. So I guess what I'm asking is could it be the lower unit making all that noise or should I take it to someone and see if they have better luck getting a better alignment. Thanks in advance for the help.

 

[Bondo]

Re: possible lower unit???

So I have a 5.0 mpi bravo 3 making noise. I thought it would be the gimbal bearing or u joints. You don't hear it at all when the motor is running turned in either direction but you do hear it when in gear. I know the shaft spins all the time and figured it needed a load in order to make noise so I replaced the bearing and u joints because the boat is 10 years old and I figured why not. The previous owner claimed he maintained it but by the looks of the wiring he did I kinda doubt it. I got the motor aligned until there were marks on all sides but the mounts are all the way up to the top up front and the marks were just a little harder to the bottom. The alignment tool went in fairly easy and turned OK but the drive was slightly more difficult to get in. I started it on the trailer and everything sounds good so I turned it side to side to see if it made noise. Still good so I put it in gear and I get noise. So I guess what I'm asking is could it be the lower unit making all that noise or should I take it to someone and see if they have better luck getting a better alignment. Thanks in advance for the help.

Ayuh,... Welcome Aboard,.... Did ya drain, 'n change the drive's oil,..??

Any metal particles in it,..??

 

[JosephPC]

Re: possible lower unit???

I have not. That is where I was going next. Do these things still use hypoid 90 or is that just outboards?

 

[MarkSee]

Re: possible lower unit???

You want to get some Mercury/Quicksilver High Performance Gear Lube for sterndrives.
Some guys use substitute lubes but might want to use the oem stuff. Many a Walmart carries the Quicksilver HPGL.

Mark

 

[JosephPC]

Re: possible lower unit???

OK thanks. I'll get some and change it tomorrow night when I get back to the boat and let you guys know what I find.

 

[JosephPC]

Re: possible lower unit???

OK. So I drained and replaced gear oil. Stuff looked just like the oil I replaced it with. 0 water 0 shavings or metal of any kind. Any suggestions on where I should look next? Thanks. Joe.

 

[Bondo]

Re: possible lower unit???

OK. So I drained and replaced gear oil. Stuff looked just like the oil I replaced it with. 0 water 0 shavings or metal of any kind. Any suggestions on where I should look next? Thanks. Joe.

Ayuh,.... What's the Noise yer chasin',..??

 

[JosephPC]

Re: possible lower unit???

INoounds kinda like a metal on metal click/clunk only way you can hear the actual noise the boat was on the trailer. You can feel a vibration when the out drive is all the way down or when you turn the drive all the way to each side. I thought it would be a gimbal bearing or u joints even though both looked great I replaced those with no improvement. I didn't remove the props yet but neither feels sloppy. That's the only thing I can think to do next.