New gimbal, input shaft and bellows - now it vibrates

[WorkingFromHome]

I had a VP certified mechanic pull my duoprop drive and replace the gimbal, input shaft and bellows. Now, I have a vibration that feels like something is out of balance between 800-1200 rpms and 2000 - 2400. It’s really noticeable and I can feel it through every surface of the boat. My bimini visibly shakes.

I told him and he cleaned the fuel regulator?! Seriously, WTF?

Obviously, since I’m posting that wasn’t it... Before lose my mind what do you all think it could be?

Is there anything I can check without having it hauled again?

 

[alldodge]

What I'm reading is

The boat had NO vibration what so ever until after the gimbal, input shaft and bellows.

Now it does have vibration

So the vibration was caused by the first repair, either U joints not correctly installed, or the U joints where not replaced and old ones where reused

Why was the input shaft replaced to begin with?

 

[WorkingFromHome]

He replaced the whole u-joint assembly (both yokes and the cross) because it was shot and had elongated the holes in the yokes. Apparently the bellows was leaking causing the bearings and joint to go bad. Sorry, I was calling that a input shaft...

But yes, the only vibration I had before was when turning or trimming the drive at anything other than neutral trim.

 

[alldodge]

Unless the engine coupler has an issue, then the upper drive was not put back together correctly.

The input shaft goes into the drive coupler, and if the older shaft damaged the coupler then the upper drive was not put back together correctly. There is no way the injectors were your issue as you know, and for the same Mech to say that might be the issue, you need another Mech

 

[Scott Danforth]

my guess is the center of the cardon joint is not centered on the u-joints.

agreed, you need a different mechanic.

 

[Sparkinator]

You asked if there was something you could check. I have an alignment tool and check my alignment annually. You can get them fairly cheaply off eBay. You have to pull your drive to do it. Your mechanic should have checked that as well when he completed all the repairs he made.

 

[GeorgeDes]

Why chase this yourself? Take the mechanic for a ride and tell him you paid him to fix an issue and he didn’t fix it!

 

[WorkingFromHome]

Why chase this yourself? Take the mechanic for a ride and tell him you paid him to fix an issue and he didn’t fix it!

Agree with you, and I am doing that, but I want as much information as possible. I'm speculating here, but I seriously doubt they want to haul it out again (on their dime) so I want to be ready. They're the only shop around with a sling lift.

my guess is the center of the cardon joint is not centered on the u-joints.

agreed, you need a different mechanic.

I usually do all my own work, but I needed the yard to haul the boat anyways and I got lazy. I guess I'm paying for my laziness now.

Unless the engine coupler has an issue, then the upper drive was not put back together correctly.

The input shaft goes into the drive coupler, and if the older shaft damaged the coupler then the upper drive was not put back together correctly. There is no way the injectors were your issue as you know, and for the same Mech to say that might be the issue, you need another Mech

This is what I'm afraid of. Either way the boat has to come out of the water and the drive has to come back off. If it's the coupler the engine needs to come out too, right? And if he messed it up once, do I really trust him to get it right?

 

[alldodge]

If it's the coupler the engine needs to come out too, right?

Yes

And if he messed it up once, do I really trust him to get it right?

I wouldn't, and you might be stuck, but your getting info to talk with an understanding of this issue, you are now in a better place

 

[dypcdiver]

I once had one of the needle rollers end up in the bottom of the "U" joint cup which pushed the crucifix off centre. I was amazed it all went back together, I thought there was not enough clearance but yes, luckily no damage was done to the 'U' joint.

 

[Saline Marina]

Some random thoughts...

I got a gimbal bearing sold as Sierra from Amazon (trying to get a greaseable bearing) and I wouldn't put that thing in my boat (!!) It was extremely "rough" and "notchy" feeling just when rolling it by hand, as compared to a hundred other rolling-element bearings I've had in my hands over the years that were perfectly smooth. There are a lot of generic bearings that will "fit" but did you get a "Genuine Penta" OEM part or one that "fit"...

Along those lines, if the proper tool was not used and the inner race was struck at any time from a hammer blow when installing it, no matter how nice of a bearing it was originally, its probably toast where the balls "brinnelled" one or both of the races.

My opinion on the drive alignment tool is that its just an aid to getting the axis of the gimbal lined up with the crankshaft, as opposed to the frustrating task of trying to align a splined bore and splined shaft that can't be seen. My opinion is that if the splines mate easily, the gimbal is aligned and cannot "misalign".

These are just some possibilities.

 

[Sparkinator]

Some random thoughts...

I got a gimbal bearing sold as Sierra from Amazon (trying to get a greaseable bearing) and I wouldn't put that thing in my boat (!!) It was extremely "rough" and "notchy" feeling just when rolling it by hand, as compared to a hundred other rolling-element bearings I've had in my hands over the years that were perfectly smooth. There are a lot of generic bearings that will "fit" but did you get a "Genuine Penta" OEM part or one that "fit"...

Along those lines, if the proper tool was not used and the inner race was struck at any time from a hammer blow when installing it, no matter how nice of a bearing it was originally, its probably toast where the balls "brinnelled" one or both of the races.

My opinion on the drive alignment tool is that its just an aid to getting the axis of the gimbal lined up with the crankshaft, as opposed to the frustrating task of trying to align a splined bore and splined shaft that can't be seen. My opinion is that if the splines mate easily, the gimbal is aligned and cannot "misalign".

These are just some possibilities.

The drive alignment tool also checks to make sure your engine is still in alignment with your drive. If transom is rotten or motor mounts loose then alignment could be causing the vibration. When we reinstalled my engine we had to pull it several times to get the engine bolted to the mounts correctly. Also had issues assembling the rear mounts correctly so we could torque them to spec.

 

[WorkingFromHome]

Well, whatever it was that caused the vibration, it's fixed.

I took the boat out over the weekend and the more I used it, the less vibration there was. Ended up going WOT for a bit and now, there's no vibration. It's smooth and quiet so I'll take it.

I did find out from the mechanic that he replaced the whole u-joint assembly. One of the yokes was loose and it was less expensive from a labor/part POV to replace the unit vs trying to rebuild.


Either way, thanks for all of your help in educating me.

 

[Thalasso]

Rebuilt mine for $50.00