growling noise coming from rear-end sounds like someone grinding gears in a car

[tray]

I have an omc 986037 drive connected to a 4.3 I believe it was replaced some years ago I'm tired of giving the marina money for repairs, any ideas what could be the problem? They just installed a new propeller in April

 

[Droid]

986037 does not turn up a search result. So what year & type of drive are you dealing with?
It's hard to believe anyone will even look at 30 + year old I/O

 

[racerone]

Check the gear oil.----Is propeller rubbing on the gearcase?

 

[AllDodge]

Droid brings up a good point, what year is the boat and what drive are your discussing. If it was a 40 yr old boat with a Merc drive that wouldn't be as much of an issue as a OMC

Racerone brings up another good point

 

[Droid]

I have a feeling it's an 80s vintage mechanical shift Fossildrive. There was no 4.3L in the electric shifts (225 odd fire yes, 3.8 & 4.3L no).

I'd also check the gear lube in the intermediate housing.