Strange noise coming from Outdrive

[bigdog]

I'm writing this Post for a friend of mine, and not a Forum member and not too computer saavy....

He has an issue (we think) coming from his Outdrive.
1988 Four Winns boat with OMC outdrive. Engine is either 150 or 175HP

Problem is when he turns steering wheel to the left, he hears a growling sound.. Someone told him the issue may be related to one of his exhaust bellows, but I don't know why that would cause any noise ?
When he steers to the right, there is no sound issue.

I'm thinking the issue possibly be related to the Gimbal bearing ? I was reading in marineengine.com the main symptom of 'Gimbal' issue is when running in gear in the water, you turn you steering almost all the way to either direction like making a turn and you will hear/feel a grumbling/growling sound/feeling.

Boat , when not in use, is on a mooring, he doesn't own a trailer. That said, he cannot take boat out of water to inspect, but would have to take to a marina $.

If it is the Gimbal bearing, what would be the approx cost to replace.
I suspect replacing the bellows would be a good time to replace, since they have to be removed to access the Gimbal.

Thoughts ?