Building a '93 Caravelle 1750 Classic Bowrider

[froggy1150]

Whe have been pushing 118+ deg here in vegas...

 

[Lou C]

Here are the OMC Cobra drive gear ratios from my 1988 Factory Shop Manual:
2.3 liter Ford 4 cyl: 2:1
3.0 liter GM 4 cyl: 1.71:1
4.3 liter GM V6: 1.68:1
5.0 liter GM V8: 1.50:1
5.7 liter GM V8: 1.41:1
7.5 liter Ford V8: 1.43:1
Not sure if they changed between 1988-1993 might have to find a later source than what I have

 

[Reserector_]

Here are all of the video clips from Wilson Lake.

 

[kcassells]

GreaT!

 

[1985 Century Mustang]

Here are all of the video clips from Wilson Lake.

That's a beautiful lake.

 

[Lou C]

Yes it is very pristine compared to my salt water harbor

 

[Lpgc]

Well done @Reserector_ , you earned your name! Great thread.

 

[Lou C]

Yep beautiful job & nice to see another boater besides myself still running an original dog clutch OMC Cobra!

 

[Reserector_]

OMC Cobra drive noise:

The wife and I were out on the lake yesterday for the first time this season.
We rode from the ramp to the ski area and opened it up a bit. I made a turn and continued, then decided to throttle back. When I did, I heard what sounded like a dry bearing all of a sudden. I may have heard a bit of a clunk or pop, as well. I continued to slow down and let it settle back to idle speed. The sound got quieter, but was still there.
We were in open water with no chance of running aground. I didn't see any debris. Prop was fine.
We continued, trying different conditions to narrow down what it could be.

I got back on plane and it was fairly quiet, but still there. High speed, low speed, straight or turning. It wasn't loud, like at first, but we could still hear a faint dry bearing sound. It sort of resonated through the hull. The engine compartment sounded normal.

The sound was not affected by steering.

When I tilted the drive up or down, it would get quiet until the angle change was complete. It only got quiet during the movement, as if the effect on the drive shaft was making the bearing behave.
It makes the noise in forward, reverse and neutral, so that (to me) narrows it down to the input shaft of the drive.

At this point, I am fairly convinced that it is the gimbal bearing going out.
I suspect that the bearing's internal cage failed, causing a bearing to wedge momentarily and go back in place, causing the pop noise followed by the dry bearing/scraping sound, caused by the bearing cage. After several seconds of dragging, the bad part of the cage likely polished in enough to get quieter.
Do I sound like I am on track, here?

 

[ScottinAZ]

OMC Cobra drive noise:

The wife and I were out on the lake yesterday for the first time this season.
We rode from the ramp to the ski area and opened it up a bit. I made a turn and continued, then decided to throttle back. When I did, I heard what sounded like a dry bearing all of a sudden. I may have heard a bit of a clunk or pop, as well. I continued to slow down and let it settle back to idle speed. The sound got quieter, but was still there.
We were in open water with no chance of running aground. I didn't see any debris. Prop was fine.
We continued, trying different conditions to narrow down what it could be.

I got back on plane and it was fairly quiet, but still there. High speed, low speed, straight or turning. It wasn't loud, like at first, but we could still hear a faint dry bearing sound. It sort of resonated through the hull. The engine compartment sounded normal.

The sound was not affected by steering.

When I tilted the drive up or down, it would get quiet until the angle change was complete. It only got quiet during the movement, as if the effect on the drive shaft was making the bearing behave.
It makes the noise in forward, reverse and neutral, so that (to me) narrows it down to the input shaft of the drive.

At this point, I am fairly convinced that it is the gimbal bearing going out.
I suspect that the bearing's internal cage failed, causing a bearing to wedge momentarily and go back in place, causing the pop noise followed by the dry bearing/scraping sound, caused by the bearing cage. After several seconds of dragging, the bad part of the cage likely polished in enough to get quieter.
Do I sound like I am on track, here?

I wouldnt say its completely off the wall, and at least its easy to check. Pulling the drive is quick and painless, and will tell you in 20 minutes if you have an easy fix, of if something inside the drive went, or is going belly up.

 

[Reserector_]

I should add that the bearing was part of an all-in-one kit from China. I should have bought quality parts from Iboats.com
The gimble bearing I got wass sealed; no grease hole to line up with the hole in the housing.
I still have the grease fitting in the hole, but someone told me that is a bad idea with a sealed bearing. You are supposed to replace the fitting with a plug to keep water out. Seems odd to me, but I guess it's a thing.
That said, I am going with a greasable bearing and OEM parts this time.

 

[Scott06]

I should add that the bearing was part of an all-in-one kit from China. I should have bought quality parts from Iboats.com
The gimble bearing I got wass sealed; no grease hole to line up with the hole in the housing.
I still have the grease fitting in the hole, but someone told me that is a bad idea with a sealed bearing. You are supposed to replace the fitting with a plug to keep water out. Seems odd to me, but I guess it's a thing.
That said, I am going with a greasable bearing and OEM parts this time.

you can leave the nipple in the hole wont bother anything if you are using a perma lube bearing. Pull the drive and see how it looks since moving it helps would think it is gimbal or ujoints

 

[bruceb58]

When was the last time you pulled the drive and checked for water in the bellows. bearing condition and drive alignment? You should be doing this annually or at least semi annually.

 

[Reserector_]

When was the last time you pulled the drive and checked for water in the bellows. bearing condition and drive alignment? You should be doing this annually or at least semi annually.

Honestly? I haven't pulled the drive since I finished the restoration back around 2021. I don't take the boat out much, or for very long at a time, so I have ignored that maintenance.
I usually only go out on the lake for an hour or so, two or three times a year, but the last time I used it was last July, when I was able to keep it at a dock and use it a few days in a row. Then I brought it home and it sat until it was time to drain it for the winter.
I highly suspect that some water got in while it was docked, and that water sat until now.

 

[ScottinAZ]

if you have a cheap chinesium bearing in there, that could well be the cause of the issue... the bellows and bearings in those kits are not the best... I use them when resurrecting a boat, as they will keep water out until the hull and driveline is proven, but beyond that, if you get a year or two out of them, you did beyond great...

there is no need to pull the nipple on the grease port... the nipple is self sealing (or should be) and isnt a water intrusion point. You likely just got a cheap bearing, that is doing cheap bearing things.... (likely short on grease when made, and since used, is under lubed and running loud)...

 

[Reserector_]

if you have a cheap chinesium bearing in there, that could well be the cause of the issue... the bellows and bearings in those kits are not the best... I use them when resurrecting a boat, as they will keep water out until the hull and driveline is proven, but beyond that, if you get a year or two out of them, you did beyond great...

there is no need to pull the nipple on the grease port... the nipple is self sealing (or should be) and isnt a water intrusion point. You likely just got a cheap bearing, that is doing cheap bearing things.... (likely short on grease when made, and since used, is under lubed and running loud)...

I hope that's all it is. I'm anxious to pull it apart, but I won't have parts and tools until later in the week. I don't want to block my driveway all week, so I will just get ready and wait until the stuff gets here.

I'm glad it failed during this "shakedown run" because we plan to take the boat four hours away to Lewis Smith Lake in Alabama during the first week in July. It would have sucked to have it fail after renting a house on the lake for four nights. Past the point of no return, now. Gotta' make it happen, Cap'n!