Chattering in out drive

[SSTKO81]

Well its that time of year again. And no time like the present to find out what's going to fail this year... Luckily this time it showed its ugly face before I got on the water. While testing the motor for the first time on the muffs this season, it started and ran beautifully for about a minute. Then suddenly a loud CLANK from the lower unit. Sounds like it had suddenly been dropped into gear (which it hadn't). I could then hear the lower unit chattering in a rhythmic pattern. When i reached out and felt the housing I could feel an obvious vibration from inside. So I took the upper bearing housing off to check it out. To be totally honest I don't see anything crazy here. Maybe the bearing is a little looser than I'd expect, but still seemed to roll smoothly despite the material suspended in the oil. I'm not totally sure what to look for here. Thoughts?

 

[Scott Danforth]

if its clanking in the lower, you need to pull the lower apart.

 

[dubs283]

Was the drive trimmed up/out when running?

 

[Scott06]

Was the drive trimmed up/out when running?

this or is the shift mechanism hung up to where it is not fully in or out off gear? Engagement teeth of dog clutch could be grinding

 

[SSTKO81]

this or is the shift mechanism hung up to where it is not fully in or out off gear? Engagement teeth of dog clutch could be grinding

It was trimmed almost all the way down. No rotation or bouncing of the prop and it would free spin while the motor was running. I’ve run into the issue with the dog clutch bouncing like that before and that doesn’t seem to be the case here. Based on the photos I assume it has plenty of oil and there are no leaks, so if it’s the upper bearing and can’t understand why it would fail. That’s would be the 3rd one in the last 10 years…

 

[Scott06]

It was trimmed almost all the way down. No rotation or bouncing of the prop and it would free spin while the motor was running. I’ve run into the issue with the dog clutch bouncing like that before and that doesn’t seem to be the case here. Based on the photos I assume it has plenty of oil and there are no leaks, so if it’s the upper bearing and can’t understand why it would fail. That’s would be the 3rd one in the last 10 years…

Did you inspect u joints and gimbal bearing? Unless you had water in gear lube or ran it low those might be more likely sources.

The bearing you showed looks fine does it turn smoothly

 

[SSTKO81]

Did you inspect u joints and gimbal bearing? Unless you had water in gear lube or ran it low those might be more likely sources.

The bearing you showed looks fine does it turn smoothly

Turns really very smoothly. The oil level is just as shown in the picture which looks good. No signs of water. It’s been a couple years since the gimbal was changed or checked, so I suppose that’s possible. U joints were checked at that time as well and they were good. The shimmer in the oil is what has me worried. Something in there isn’t happy

 

[Bondo]

Turns really very smoothly. The oil level is just as shown in the picture which looks good. No signs of water. It’s been a couple years since the gimbal was changed or checked, so I suppose that’s possible. U joints were checked at that time as well and they were good. The shimmer in the oil is what has me worried. Something in there isn’t happy

Ayuh,...... Drain it, 'n look for metal,.....

 

[dubs283]

I'd pull the drive and inspect rotating components

If the drive hasn't been removed for service/inspection in two years, it's due

 

[SSTKO81]

Ayuh,...... Drain it, 'n look for metal,.....

As usual Bondo, I'm afraid i'm gonna have to agree with you. Fact is you just don't know what the damage is until you taker her apart and check it out. -guess I know what I'll be doing in my spare time this week.

 

[SSTKO81]

As usual Bondo, I'm afraid i'm gonna have to agree with you. Fact is you just don't know what the damage is until you taker her apart and check it out. -guess I know what I'll be doing in my spare time this week.

I'll add here, that my understanding is that the gears themselves are pretty damn tough, and its odd to have them damage themselves especially under light duty and good lubrication. I'm leaning toward some kind of bearing failure. I'll update here once i've got it figured out.

 

[nola mike]

It was trimmed almost all the way down. No rotation or bouncing of the prop and it would free spin while the motor was running.…

Please tell me you you didn't use your hands to do this.

 

[ROY WILLIAMS]

your water is in the outdrive .. then its a corrosion ,,, outdrive is taking it off and inspect all those gears and bearings ..
picture is a lot of corrosion inside of it ..

my outdrive is every year off that cap top and it is inspecting it in the winter .

 

[SSTKO81]

Please tell me you you didn't use your hands to do this.

I live life dangerously. LOL
Just an update here. I pulled the outdrive tonight and found everything to initially look good. Gimbal bearing is nice and smooth, no play. U joints are tight and well greased. No signs of water intrusion (corrosion) that would suggest the bellows were leaking or the gasket was bad. I DID do a little research and found that at some point an Alpha one upper cover/bearing cup had been placed on this pre-alpha drive. I don't know if that makes a difference. But it's another piece to the puzzle.

 

[dubs283]

at some point an Alpha one upper cover/bearing cup had been placed on this pre-alpha drive. I don't know if that makes a difference.

The upper driveshaft/bearings must be set to a specific preload prior to shimming the gear set.

If someone swapped out a top cap/bearing cup and didn't check the preload it's possible the shims under the cup are incorrect and the preload is too loose/tight causing the issue

 

[SSTKO81]

The upper driveshaft/bearings must be set to a specific preload prior to shimming the gear set.

If someone swapped out a top cap/bearing cup and didn't check the preload it's possible the shims under the cup are incorrect and the preload is too loose/tight causing the issue

Any crash course advise on how to check/set preload?

 

[dubs283]

You'll need a rolling dial torque wrench.

Need to set the shims to achieve 3 -7 lb/in rolling. Measurement is taken with the drive gear/bearing pack/u joint assy removed from the housing with drive/driven gear height/lash already set.

You're best off using the oem manual, bit too in depth to fully explain here. Manual #14 should be the one you need, guessing this is an older vintage gen 2

 

[SSTKO81]

You'll need a rolling dial torque wrench.

Need to set the shims to achieve 3 -7 lb/in rolling. Measurement is taken with the drive gear/bearing pack/u joint assy removed from the housing with drive/driven gear height/lash already set.

You're best off using the oem manual, bit too in depth to fully explain here. Manual #14 should be the one you need, guessing this is an older vintage gen 2

 

[SSTKO81]

I’ll invest in a dial toque wrench -good to have anyway… I have a manual as well so I’ll dig into it. This is actually, I believe a Pre-alpha 81-82 vintage

 

[dubs283]

Post a serial number of its still legible. Pictures help too

If it's early 80's vintage you'll need either manual #3 or #6