thud from motor or drive while in neutral (pics added)

[nailem]

86' sunrunner 5.0l merc. alpha 1 gen 1
went out to watch the fireworks last night, boat started fine and ran fine idle through the marina and a short 10min half throttle run. back to idle and floated for a few minutes to see if i wanted to stay were i was at the a started to hear a thud. it almost sounded like a slip then a thud ( i was in neutral) it did it a few more times and stopped. it was not a continuous thud thud thud but more of every few seconds then nothing then thud again.

shut it down check the engine (it was 10:00pm so did not see much). after fireworks started fine and ran back to marina. this time while idling back to my slip it did it a few more times but much softer and less harsh.

after i got back i thought maybe i could smell gear lube but i think my mind was just searching. also about 100 boats were all coming back at the same time so lots of different exhaust and motor smells hard to tell what was mine.


i do know the thud was not fireworks.

 

[mkast]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

started to hear a thud. it almost sounded like a slip then a thud ( i was in neutral)

A slip in neutral?

 

[nailem]

Re: thud from motor or drive while in neutral

Re: thud from motor or drive while in neutral

i know, it doesnt sound right but i was in neutral and it felt like a slip then a thud. almost like the hub on the prop is spun and it was slip and then catch. i made sure it was in neutral and not stuck in gear.

 

[urnmygto]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

Could it be a hub, or ujoints? Wa thier any vibs when you had it in neutral or when it went into gear>???

 

[nailem]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

no vibration going into and out of gear. itactually goes in and out real smooth but oncein gear maybe a little louder than normal.

i took it out today and while idling out of the marina it slipped once. then when i planed out i could hear the drive click, click ,click. backed off and headed in. it maybe slipped a couple more times. youcould smell gear lube in the boat. i pulled the boat out of the water and got it home. i had about 1oz ofwater in the gear lube and the rest as white. i only got about 1qt of lube out.

i just replace the bellows this spring. someone said it is my upper seal. but could it be my bellow leaking? i do not have any water in the boat.

if it is the upper seal and i relace my lube am i out of the woods? as the damage allready been done since it is slipping? thanks

 

[nailem]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

i guess i dont know what the upper seal is. is it the gasket and oring that goes in between the upper and the transum? i dont know if im saying the right terms.

 

[Bt Doctur]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

Could be a chipped tooth in the drive. Have you ever hit anything or damaged the prop at any time within the last 2 years?

 

[nailem]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

this is my second year with the boat. i have done pretty much a full tune up on it but out side the bellows and water impeller i have never gotten into the drive.

i took the top cove off and the gear that is horizonal has one missing tooth the vertical gear is missing 2 and 1 is chipped. it punched a hole in the inside looking down near the aft of the drive. there is no rust and it does not appear to be any heat marks. i feel the teeth broke first.

what would cause this? i have never hit anything hard. i have hit some soft muddy sand that just felt like it bogged the motor for a second but no impact.

am i better off buying an assemble upper or try putting an empty one together? how much am i looking at?

 

[urnmygto]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

About 500 if it's an alpha, I just looked at ones on line for 3yr warranty

 

[Bt Doctur]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

Glad that you looked, a chipped tooth is impact damage at some time.One cust. hit a plastic garbage bag and chipped a pinion gear in the lower.A soft "thump,thump" As long as the housing inside has not been damaged or the missing tooth ground into powder you might only have to do gears and seals..I`ve installed quite a few SEI drives, havent seen a problem.

 

[nailem]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

thanks guys but it looks like it did the damage when it broke. small hole punched through the aft side of the Boer down by the vertical gear. i think the tooth broke punched the hole and thats when i could smell the gear lube. i must have just happened last night because there is no rust at all inside. funny thing is i have been out 3 times since i hit the sand.

how do i flush the lower of the metal scrap? it is a alpha 1 gen 1.
urnmygto, can you tell me where you found those prices. so far $685 is the best i can find.

 

[Bt Doctur]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

$595.00 to your door

 

[nailem]

Re: thud from motor or drive while in nuetral

Re: thud from motor or drive while in nuetral

$595 from where?

i talked to a friend that said that i should be able to get this fix under my insurance. has anyone had any experience with that. if the damage was due to an impact i think i could get it covered. i know i need to call around tomorrow to See how my local shops are but if they are backed up i wounder if my insurance will let me do the work. i know these are not necessarily questions anyone can answer im just typing out load. thanks again.

 

[nailem]

Re: thud from motor or drive while in neutral

Re: thud from motor or drive while in neutral

how worried should i be about the lower, it still shifted and sounded ok but i hate to buy the upper just to do damage to my lower in a month.

 

[nailem]

Re: thud from motor or drive while in neutral (pics added)

called it into the insurance and a adjuster is coming out in 2 days. i found a marina that can get it in in a week. im sure he will look at the lower but what are your thoughts?

 

[Bt Doctur]

Re: thud from motor or drive while in nuetral (pics added)

Re: thud from motor or drive while in nuetral (pics added)

It starts like a long story
A long time ago i hit something, I didnt break or bend my new SS prop so I must still be ok.Ooops, theres another one. gee why cant I damage this SS prop, .look at all the money I saved on propellers.But wait, whats that thumping noise/whine/grumble/vibration/thump i hear??????????? Could it be unseen damage?????????????
Maybe I should have had an aluminum prop.
Yes you should have, they do bend and give up the ghost a lot sooner that SS.

 

[bigskiohio]

Re: thud from motor or drive while in nuetral (pics added)

Re: thud from motor or drive while in nuetral (pics added)

insurance will cover it and let mech do the work or get you new drive from
sei. merc drive would probably total boat and maybe buy it back and put sei drive on it yourself

 

[nailem]

Re: thud from motor or drive while in nuetral (pics added)

Re: thud from motor or drive while in nuetral (pics added)

is the top cover something that should be pulled off and checked during routine maintenance?

 

[Bondo]

Re: thud from motor or drive while in nuetral (pics added)

Re: thud from motor or drive while in nuetral (pics added)

is the top cover something that should be pulled off and checked during routine maintenance?

Nope..

 

[NickAndJena]

Re: thud from motor or drive while in neutral (pics added)

Wow, this story sounds very similar to a situation we found ourselves in last week. Boat was running fine, and then all of a sudden a knocking or banging noise ensued. We pulled off to the nearest beach and after I didn't find any apparent damage to the prop (aluminum) we started the engine again and the noise persisted. Well ok there was some damage to the prop, but the sound made us think a blade got ripped off or something. So we shut off the engine and asked the nice people camping nearby for a ride to the boat ramp so we could pull the trailer over to the location we hastily beached.

I haven't torn the stern drive apart (yet) but did notice the noise was coming from the upper portion, so I checked the gear oil. It was topped off just right but then I noticed A LOT of metal flakes in the oil. We have an '88 Alpha One (Gen I -- I think) and don't feel comfortable doing the rebuild myself (even after we just rebuilt the stringers just a couple weeks ago).

Anyway, we do have insurance on the boat. I didn't think about asking them for some help but I will now. Please let us know how it goes. This weekend I'm going to take the top cover off to inspect but I'm guessing I'll find some broken teeth too ....

My question for the group is... Are these SEI stern drives for real? Or should I pay the extra cash to replace the drive with a genuine Merc?

Thanks,
Nick