How should lower unit sound when boat is running on muffs

[gwgautney]

I have a 3.0 mercruiser it is a pre alpha drive originally had an mr drive on it. My question is I just replaced all bellows gimbal bearing and fixing to change lower unit oil and water pump. I got it all back together today and had it running and heard a small roar from the outdrive. I owned one of these before but it has been years. Should I be hearing anything from the outdrive. I know the shaft is spinning. It doesnt sound horrible just wanting to know what I should be hearing and if this is normal. Everything shifts fine. Noise is coming from outdrive itself i thought it was u joints at first but it is from upper housing I believe.

 

[bspeth]

Re: How should lower unit sound when boat is running on muffs

I cant hear anything with mine.I think somethins notright.Can you describe the ruckus sir?

 

[gwgautney]

Re: How should lower unit sound when boat is running on muffs

Just a steady roar not to loud but its there. No clattering or clunking

 

[thumpar]

Re: How should lower unit sound when boat is running on muffs

I never heard anything from mine other than exhaust and a slight rubbing noise when my gimbal bearing was going. After the new bearing nothing except the cluck when shifting. Can you tell where it is coming from?

 

[gwgautney]

Re: How should lower unit sound when boat is running on muffs

upper housing i think i will check it again tomorrow after lu oil change and report my findings

 

[thumpar]

Re: How should lower unit sound when boat is running on muffs

You could pull the top cap and check the upper bearing. If it was ever low on oil the upper bearing and gears could wear.

 

[gwgautney]

Re: How should lower unit sound when boat is running on muffs

if it was low on oil would that cause it??

 

[Grub54891]

Re: How should lower unit sound when boat is running on muffs

if it was low on oil would that cause it??

Yes,the upper bearing in the cap needs all the oil it can get. If the oil was low it will eat that bearing.the unit should be full up to the ventscrew,or if it has a remote resivoir,even fuller.

 

[gwgautney]

Re: How should lower unit sound when boat is running on muffs

How hard is it to replace the upper bearing if that is my culprit.

 

[Bondo]

Re: How should lower unit sound when boat is running on muffs

upper housing i think i will check it again tomorrow after lu oil change and report my findings

Ayuh,.... Was there a bunch of metal in the drained oil,..??..??

Drives are Alot Louder when they're not under water, 'n ya got yer ear next to it,....

 

[gwgautney]

Re: How should lower unit sound when boat is running on muffs

No there was no metal in drained oil. Lol on the under water . I think its good the drive has been sitting in a shed for about three years just trying to make sure alls good and again it has been a while since I had on outdrive. Just trying to make sure I'm good.