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86 omc400 clunk

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plane_crazy

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stern drive makes a clunk/smooth, clunk/smooth under power. same clunk at slow speed and fast. Bottom end gears and clutch dogs look like new, top end the same . Replaced ball gears. Ran all season with clunk and no visual internal damage.
What could it be. only slop in outdrive is the tru-course steering. Could this be the problem?
 
ok lets try this again. You have a stringer drive correct ? Must be cause you posted you have tru course steering.

The same drive i have, and know better then my wifes you know what that i am married to for 23+ years, and she tells me the 4 kids i am supporting are my kids.

So look at the little gear that drives the half moon gear that raises the drive.

Raise the drive say 3/4 of the way to see the gear clearly. See a plastick insert ?

Remove the insert, there is a allen head screw in the hole ?

Know what the screw does if you have one ?

It applies resistance to the drive so when you hit something it allows the drive to raise up so the drive doesn't get damaged. Understand ?

If to little resistance when you are powering thru waves the drive will raise up and slam down, Understand ?

Turn that allen head screw in a few turns and then put back on the plastick insert, and then run the boat, still slamming up and down ?

Then turn in the screw another few turns.

Understand ?

This is your problem in my humble opinion if what you posted about all else is ok with the internals of you drive.

Understand grasshopper ?
 
Chief..this is interesting reading. At the risk of hijacking the thread (though possibly related???), could this also be the issue when I sometimes hit the reverse too much and the outdrive pops up? I have an 84 OMC 800 on a 5.0L. Of course I never try and race out of the dock in reverse, but like I said, somtimes I don't know my own strength and give it a little too much juice!
 
edjunior said:
Chief..this is interesting reading. At the risk of hijacking the thread (though possibly related???), could this also be the issue when I sometimes hit the reverse too much and the outdrive pops up? I have an 84 OMC 800 on a 5.0L. Of course I never try and race out of the dock in reverse, but like I said, somtimes I don't know my own strength and give it a little too much juice!
Click to expand...

that is the exact symptom of a tilt clutch needing a tension adjustment, ed
 
chiefalen said:
ed yep Hy knows that the stringer has it's own quirks. and as Hy posted thats classic tilt clutch problem, needs adj.
Click to expand...


Thanks chiefalen. You were right on. 2 turns of the clutch adjust screw and no more clunk, just a lot of sooooth.

Thanks for the quick reply and help.
 
I still don't get that clunk think though.

I've ran down the lake with no quadrant gear, and nothing clunked....

weird,
but cool it fixed it!

way to go Chief
 
what happens is in the ocean with waves you come, up over a wave and for a second the bottom of the boat is lower then the drive the drive lifts and then the thrust of the prop slams it back down.

Don't ask me how i know this to be true, but most i post here has happened to me.
 
Outstanding. Thanks guys. I haven't even had time to pull my boat up and get it ready for the season yet, but that will be part of my spring prep for sure. Boy, never even thought to ask about it...sure glad I stick with reading these posts! Thanks also to Plane_Crazy!
 
My kid had the boat out and said all is good. I'll take his word for it untill I get a chance to try it. Of course he's said he's never hit anything and the marks on the stainless prop are from the water, Ya right.
 
plane_crazy said:
My kid had the boat out and said all is good. I'll take his word for it untill I get a chance to try it. Of course he's said he's never hit anything and the marks on the stainless prop are from the water, Ya right.
Click to expand...

haha....your kid and mine must have went to school together, I've heard the same story :D
 
if it were coming in and out of gear then i would say the dog was going. Your not hearing a clunk and the revs go up real quick then you feel it kicking in again the drive ?
 
chiefalen said:
if it were coming in and out of gear then i would say the dog was going. Your not hearing a clunk and the revs go up real quick then you feel it kicking in again the drive ?
Click to expand...

The internals of both upper and lower units look brand new. The clutch dog shows no wear. RPM's never changed during clunk. I even rotated the dog so the reverse side was driving the forward side, no difference.
 
OK. The neighbour and I went for a run tonight. The problem is stll there.
Idling down the canal it goes about 10 feet clunk, 10 feet clunk. Same thing at higher RPM. No RPM change when it clunks.
I'm lost. I'll service the tilt clutch, but I don't think thats it.
Like I said before, we ran the whole season last year with the clunk and no visible sign of wear.
 
ok you lower cable needs adjustment. and heres how.

help center omc

You need nominal neutral adjustment

There is a ton of info all those links are spot on, and i couldn't write it better myself.

Doo the adjustment quick like. Or your gonna be asking for more links on like gears and dogs.

May i ask a few questions?

You had the drive apart for a impeller change?

The water pump shafts splines look good? Greased good with spline grease ?

You ever have the ball gear main shaft out and looked at the splines that enter the coupler?

It's a one piece coupler. Not the rubber inner core one.

I'm asking for a reason. I don't want the splines to go on the coupler like it did for me and left me stranded.

The water pump shafts also went on me and left me stranded a few weeks after the coupler splines went.

Just asking don't get pissed at me i don't want you guys stranded is all.

I just replied to someone on how to get to the main ball shaft to remove, without pulling the cable. I can copy and pase here or you can go back a few threads and read it
 
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