U-joint growl?

gcundiff

Recruit
Joined
Jun 22, 2012
Messages
2
I recently acquired a 1999 Stingray CS 220 with a 5.0L EFI, ALPHA ONE and only 120 hours on it. It runs great and sounds fine until I make the slightest turn and then it sounds like the prop is cavitating with really loud growling. Can you experienced boat guys tell me what to look for in trying to diagnose the problem? What measurements do I need to take, settings on the lower unit, etc. I can take photos and post also. I look forward to your suggestions. Thanks.
 

H20Rat

Vice Admiral
Joined
Mar 8, 2009
Messages
5,199
Re: Cavitating or?

Re: Cavitating or?

sounds like you have either an alignment problem or a u-joint that is shot. I highly doubt it is the prop cavitating, or ventilating even.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,544
Re: Cavitating or?

Re: Cavitating or?

You need to determine if it is gears grumbling or excessive rpms. Usually a slight turn off centerline won't cause "ventilation" (sucking air in from above the prop) and resultant increase in rpms and loss of speed, but if if your CV joint is shot it can start immediately.....just as soon as you get the thrust off center. In that case, the farther you turn the helm the louder and more dangerous it gets. 120 hours seems short for such a massive problem however.

Mark
 

gcundiff

Recruit
Joined
Jun 22, 2012
Messages
2
Re: Cavitating or?

Re: Cavitating or?

Thanks guys. It does not seem to effect rpm or speed whatsoever. This boat was in the family so I know it only had 120 hours on it. Short of taking to shop, any suggestions on diagnosis?
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Cavitating or?

Re: Cavitating or?

If the boat was run a lot in shallow conditions with the outdrive raised to maximum operation limit it might cause premature
universal problems.
I'm no I/O expert but I believe if you turn sharp at no wake speed the universal will rattle or rumble.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: U-joint growl?

Yeah, and poor maintenance over those 13 years could make for a loud u-joint despite the low hours. Especially any problem with the bellows. I'm going to move this whole thread to the Merc I/O section. Does not sound like prop to me. Good luck, and welcome aboard!!!
 
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