knocking noise when turning

Texas Parrothead

Petty Officer 2nd Class
Joined
Sep 9, 2009
Messages
149
Hi all

I am newly registered to the forum but have been reading it as a guest for about 13 months. I want to thank everyone for the invaluable information I have been able to acquire from your posts over the last year.

I bought a '93 20 ft Chaparral with a 4.3L from a Marine Max dealer in September of 2008. The dealer checked it out from top to bottom and did some work to the outdrive before we took ownership. We have had no problems with the boat and have had it out about 8 times since we bought it.

Yesterday we had it out on the lake with the family and my 14 year old got up on his wake board for the first time. Water conditions were great and we had a fantastic day!

The problem is that I noticed that I am now getting a knocking sound from the outdrive when I turn the boat. The knocking does not exist when I am going straight but when I turn there it is. It is loudest when the wheel is hard over but still exists in any turn.

Any thoughts on what this could be and if I am now facing a large (costly) repair?

Thanks to all for your insight.
 

Rocky_Road

Lieutenant Commander
Joined
Oct 8, 2008
Messages
1,798
Re: knocking noise when turning

My first suspicion would be the u-joint...not to hard to find out!

Let's wait for some other suggestions....
 

a70eliminator

Captain
Joined
Sep 9, 2007
Messages
3,762
Re: knocking noise when turning

Right on, classic sign of a worn out u-joint repair ASAP if let go it can tear the bellows and sink your boat, that's what I've heard anyhow.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,133
Re: knocking noise when turning

Any thoughts on what this could be and if I am now facing a large (costly) repair?

Ayuh,... Who's/ What outdrive,..??
 

Texas Parrothead

Petty Officer 2nd Class
Joined
Sep 9, 2009
Messages
149
Re: knocking noise when turning

Sorry for not responding sooner.

The outdrive is an Alpha I. I just dropped it off at the marine shop for it to be looked at. I will post later with what they find and what they are quoting for repairs.

Thanks to all.
 

Bronc Rider

Petty Officer 1st Class
Joined
Sep 1, 2009
Messages
255
Re: knocking noise when turning

Sounds like u-joints, maybe a gimbal bearing as well.
If that is the case, its an easy fix.
 

Texas Parrothead

Petty Officer 2nd Class
Joined
Sep 9, 2009
Messages
149
Re: knocking noise when turning

Thanks master. The shop said the same thing, they will also check the alignment.
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: knocking noise when turning

I would let them talk me into a new drive bellows now too (since it is your money and all!).
 

Texas Parrothead

Petty Officer 2nd Class
Joined
Sep 9, 2009
Messages
149
Re: knocking noise when turning

Thanks. ;)

I am hoping the bellows is still good since it was replaced last September when I bought the boat.
 

Texas Parrothead

Petty Officer 2nd Class
Joined
Sep 9, 2009
Messages
149
Re: knocking noise when turning

Hey Maclin

You are in the town next to me. I live in Keller. I took the boat to Taylor marine on lake grapevine. Have you used them or heard anything about them? The work that was done on the boat before was done by Marine Max on Lewisville, but being a dealer they were too expensive for me.
 

Texas Parrothead

Petty Officer 2nd Class
Joined
Sep 9, 2009
Messages
149
Re: knocking noise when turning

ok, so here is what the service center found.

Nothing.

They pulled the outdrive and said the u joints and bearings looked new (they were just replaced September 08). They also reported that there was no water in the drive. They launched the boat and heard the knocking when the wheel was turned about 90% over. They brought it back in and pulled the drive again and had 2 other techs look at it. They all agreed everything looked new.

They then checked the motor allignment and said it was "ever so slightly" off alignment but was within tolerance. They are attempting to fine tune the alignment but are having an issue with the motor mount not wanting to adjust any further. They are attempting a couple of "tricks" to see if they can get the alignment perfect.

The service center said that most boats make a knocking noise when turning hard over and that I may just have a boat that is 10 - 15% loader then most.

My issue is that I had never heard the knocking as loud as it was last weekend, so this is a new noise or louder then before. We will see if the motor alignment helps.

Any feedback is appreciated. I am wondering if switching the prop to a 4 blade may help as i understand 4 blades tend to run smoother then 3 bladed props. I had wanted to go to a 4 blade with increase pitch anyway to get a better hole shot.

Thanks to all!
 

Dave1251

Petty Officer 2nd Class
Joined
May 18, 2009
Messages
151
Re: knocking noise when turning

Something does not sound right here. It is not normal for a knocking sound if everything is working right. The u-joints are stressed when at full lock, but knocking noise is telling you some part is damaging it self.

Take it to another shop and have it fixed right before you end up with a large repair bill.
 

Bronc Rider

Petty Officer 1st Class
Joined
Sep 1, 2009
Messages
255
Re: knocking noise when turning

Just about all the mercs I have run were old. I can honestly say every time I developed a knock or growl when turning a problem was found. I can?t see why it would be normal for a drive to make noises when turning.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,592
Re: knocking noise when turning

I would just replace the joints. Sometimes hard to tell by hand if they are bad. Very possible that when they were installed last Sept that they were installed incorrectly. If one needle bearing fell over when the caps got put on, you could have a problem that you wouldn't detect by feeling them by hand.
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: knocking noise when turning

I'd tell them to go ahead and replace the u-joints. Not really that expensive, and it eliminated them as a possibility. I don't know what "tricks" they can do to solve alignment other than adjusting the motor mounts, but whatever.
 

Texas Parrothead

Petty Officer 2nd Class
Joined
Sep 9, 2009
Messages
149
Re: knocking noise when turning

Thanks all.

What would be a fair "ballpark" price to have u Joints replaced on a Apha I?
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: knocking noise when turning

Hey Maclin

You are in the town next to me. I live in Keller. I took the boat to Taylor marine on lake grapevine. Have you used them or heard anything about them? The work that was done on the boat before was done by Marine Max on Lewisville, but being a dealer they were too expensive for me.

We just moved here, I keep the boat back in Kansas by the lake and go back there for camping and boating. I am not familiar with any dealers here. Yet...!
 

Texas Parrothead

Petty Officer 2nd Class
Joined
Sep 9, 2009
Messages
149
Re: knocking noise when turning

Very pleased to announce that by aligning the motor they were able to get the knocking noise to go away. I picked up the boat on Saturday and test drove it doing turns at all speeds and did not hear the knocking anymore.

Now thay my boat is fixed I am "Whole" again!
 

picklenjim

Chief Petty Officer
Joined
Mar 11, 2009
Messages
528
Re: knocking noise when turning

Any feedback is appreciated. I am wondering if switching the prop to a 4 blade may help as i understand 4 blades tend to run smoother then 3 bladed props. I had wanted to go to a 4 blade with increase pitch anyway to get a better hole shot.

Thanks to all!

If you want a better hole shot you would want to decrease the pitch.If you were to switch to a 4 blade you need to go one size lower in pitch just for starters beings you have more blade hookin up.It takes more power to turn a 4 blade.I would recommend with a 20' boat with v6 that you stay with a 3 blade and drop 1-2 sizes in pitch.
 
Top