Gen II Alpha Growl, vibration when hot.

[Howard Sterndrive]

UPDATED 07/07/14 see last posts



I put a 116 upper on my Gen II V6 1.8? ratio last fall before storing the boat and noticed a bit of a growl, more pronounced after a longish run. Seems to almost disappear in neutral, noticeable at idle in gear and at slow plane. Didn't go away after break -in.
Still here this spring, Can't really detect at WOT due to other noise/ wind etc.

The front end of the upper felt hot to me when running back and feeling it just off plane. I added a drive shower just because I had one here.
Changed gear lube - looks fine. some "fur" on lower magnet - nothing serious considering break in of upper.

Last week I changed the gimbal bearing and checked the alignment. Alignment was off a touch, now perfect. Old gimbal bearing felt smooth, but I put a new one in anyway.
I noticed the paint crispy and flaky on the "nose" of the upper just behind the foam seal - heat?

First run- fairly silent. Second outing - there's the growl on slow cruise. it's back.

I took the lid off the upper expecting to find an issue, but gears and top bearing look great. I can, wobble the vertical shaft a fair bit, but figure this is normal without the support of the top cover bearing.

So my options now -
1. tear into the lower - although propshaft turns smooth as silk and lube always clear.

2. ignore it...

I was wondering if it's just new, tight U joints? and the "working" around of the driveshaft during drive removal might have been why the vibration went away temporarily.

Any suggestions how to proceed? About 25 hours on the upper now.

 

[alldodge]

Heat and noise would make me get further into it. Maybe check the preload on the drive shaft and shimming.

 

[Howard Sterndrive]

went for a run with another prop, same.
just pulled the drive back off - looked at the input shaft seal - it looks good - I think the flaky paint is just flaky paint. The U joints are not tight, but I greased them a bit. Greased the gimbal again and rechecked alignment. Pressure and vac tested the drive. Going for another spin....I just can't see any issue.
If it's in the lower, I suppose it'll get worse before it gets better.

 

[alldodge]

Mentioned the drive shaft preload because it would be the easiest to check just working on the top half. Easiest that is if you have the dial inch pound torque wrench.

Hope you get it figured out before to long.

 

[achris]

If the drive is still under warranty, send it back...

 

[Howard Sterndrive]

the upper is under warranty, the lower is not. Costs me about $250 in shipping to do a return from Canada. They don't cover int'l ship.

 

[achris]

the upper is under warranty, the lower is not. Costs me about $250 in shipping to do a return from Canada. They don't cover int'l ship.

Bugger! Ok, drain the upper, pull the cover off and have a look at the gear teeth faces. And look at the bearting surfaces of the bearing in the top cover too. That one is quite common to go bad just because it's not immersed in oil all the time. If that all looks ok, then pull the drive, slpit it and have a feel for a little bit of play/clearance between the drive and driven gear. You should be able to just rock it between drive and 'over drive', backlash... If that's ok, take the drive gear and bearing pack out and check the bearing pre-load. I've seen plenty of noisy drives, and it's usually a bad bearing. You may have to pull the input shaft bearing apart and do a visual on them too...

Good luck....

 

[Howard Sterndrive]

Update: I changed the lower unit - picked up an SEI lower so now my whole drive is under their warranty. Noise gone!

I still have a growl at no wake when steering full turn, must be ujoints as the gimbal is brand new. The U joints look and feel great and have only a hundred or so hours on them. I'm not going to worry about it. I read an old post from DonS. that said some u joints just make noise.

I took a long run yesterday. Ran great! yay!

 

[Bondo]

Update: I changed the lower unit - picked up an SEI lower so now my whole drive is under their warranty. Noise gone!

I still have a growl at no wake when steering full turn, must be ujoints as the gimbal is brand new. The U joints look and feel great and have only a hundred or so hours on them. I'm not going to worry about it. I read an old post from DonS. that said some u joints just make noise.

I took a long run yesterday. Ran great! yay!

Ayuh,.... Sounds Great,.....