Knocking sound

[thunder219]

I have a 94 G W Invader that I bought last year and it has a slight knocking/ thumping sound while under power coming from the outdrive. The guy I bought it from said he had a dealer check it in 95 and said some boats do this. He has ran the boat up until I bought it and I used it all last summer.
It has a 4.3 merc. I think I am going to take it off and check the U joint before the summer but I wanted to ask people that may another idea to what it might be.
I am mech. inclined and have a manual but wanted to see if this would be something to try or take to a dealer so I dont have to take him a basket case of parts.
Thanks for any help on this.

 

[ripped_78]

Re: Knocking sound

More than likely it is the u-joints. I had the same problem last summer and the shop charged me $500 to replace them, but it took care of the problem.

 

[Bondo]

Re: Knocking sound

If it's been since 1995,............

It's Way Overdue for a Major Inspection,.... If Nothing Else.......

As long as you've got a Manual,+ iboats' forums,......

It's a Reasonably Easy Task...........

 

[thunder219]

Re: Knocking sound

I dont know what he has done as far as service since 95, I just know that is when he said that he had a dealer look at that.
Looking in the manual it says that I will need a u- joint retainer tool. My question is, is this a tool that I need or is there something else that will work without damaging anything? Also, what about the shift cable stabalizer(do I need to buy one or make something up?
I appreciate any and all help given. I rebuilt an OMC outdrive last year but it was a pain and just dont want to get in over my head. Thanks again.

 

[thunder219]

Re: Knocking sound

If it's been since 1995,............

It's Way Overdue for a Major Inspection,.... If Nothing Else.......

As long as you've got a Manual,+ iboats' forums,......

[b]It's a Reasonably Easy Task...........

[/b]


Sorry, I didnt see your last statement before I typed my last post.

 

[Don S]

Re: Knocking sound

Looking in the manual it says that I will need a u- joint retainer tool.

What manual do you have. Lots of people say that but only have a Clymers or Seloc manual that just hints at how to do things.

Here is a link to an online OEM manual for the Alpha I Gen II drives.

http://www.boatfix.com/merc/Servmanl/14/14cover.pdf

 

[thunder219]

Re: Knocking sound

It is a service manual # 14 from merc.
I found that and man. 25 on ebay for 15 bucks for both. I bought (I think ) clmers for my old OMC and was not real impressed with it.