Rusty u joints bravo 3

[timharper89]

I have a 97 rinker 232 with a 7.4 bravo 3 merc. I bought it late in the season last year and being honest I was lazy and didn't pull the drive last year during winterizing. I only put about 10 hours on it this year. I had intermittent growling with sharp turns under heavy load a few times when pulling tubes and whipping them around.

When I pulled the drive today I found a decent amount of rust on the u joints. Gimbal is very smooth running and the u joints are also smooth, and everything is well greased. There is no water in the bellows but obviously there is rust, so water is coming from somewhere. The bellows appear to be in good shape with no obvious cracking, though it is admittedly difficult to inspect . There is no drive oil in the bellows. Just wondering what the possibilities for water intrusion are and what i need to fix. U joints and gimbal replaced? Is there supposed to be an o ring where the drive inserts into the housing around the bellows? There was not one when I removed the drive. My alpha one used to have one.

I also found three metal plates of some sort loose in the drive when I removed it. Anyone know what they are supposed to be for?

I will attach pictures

 

[alldodge]

had intermittent growling with sharp turns under heavy load

That's either gimbal or U joints.

Water has gotten in, look on the transom side to see if the seal is intact next to the gimbal. Looks like ITEM 11 is missing

If it's intact then one of the seals has been leaking

The plates are parts of the exhaust shutters

 

[timharper89]

That's either gimbal or U joints.

Water has gotten in, look on the transom side to see if the seal is intact next to the gimbal. Looks like ITEM 11 is missing

If it's intact then one of the seals has been leaking

The plates are parts of the exhaust shutters

Thanks for the response. Should I replace both since water has been in there? Do I need a full u joint assembly or is there some other way that is less expensive to replace them?

On the transom side. Does that mean on the outside or inside the boat? I don't know what you mean here.

Item 11 seems to be connected to the bellows, no? That would be behind/ inside the bell housing? I see what looks like that part in there.
Exhaust shutters? I don't see those in my manual. What do I do with them?

 

[alldodge]

The seal is ITEM 9 and only way to get water in from the transom side is if the bilge stays wet and gets sloshed around while under way

You can replace just the U joints ITEM 24 but not sure they are the problem, but they might be.

You said U joints feel good, and if it was mine I would replace the bellows and gimble bearing. Run it and see if the U joints are needed after. Could do them all and just run next year. Don't forget to grease the coupler

Exhaust shutters are ITEM 7 and are under the elbow

 

[Bondo]

Should I replace both since water has been in there? Do I need a full u joint assembly or is there some other way that is less expensive to replace them?

Ayuh,..... The u-joints can be replaced, without changing the entire assembly,..... You'll probably find tiny ridges on the crosses when you push 'em apart, regardless how smooth the feel when assembled,...

The shutters live at the top of the y-pipe, just after the risers,....

 

[Scott06]

Ayuh,..... The u-joints can be replaced, without changing the entire assembly,..... You'll probably find tiny ridges on the crosses when you push 'em apart, regardless how smooth the feel when assembled,...

The shutters live at the top of the y-pipe, just after the risers,....

Agreed I had pretty deep ridges on the u joints for my Alpha gen 2 but they felt smooth by hand.

To the OP you can usually cross those U joints with an automotive one. I don't know the cross for bravo U joints but the ones with internal retaining rings for a alpha one are a moog 315G or equivalent. Maybe you can match them up.

Also with that much corrosion you may have rust on the yoke where the drive input shaft goes

 

[timharper89]

The seal is ITEM 9 and only way to get water in from the transom side is if the bilge stays wet and gets sloshed around while under way

That is not a problem. Bilge gets wet but not that wet.

You can replace just the U joints ITEM 24 but not sure they are the problem, but they might be.

I have read some saying that you can use automotive parts here for much less. Any youth to this? Suggestions on how to find the matching part?

You said U joints feel good, and if it was mine I would replace the bellows and gimble bearing.

I was afraid i would need to replace the bellows...i did that on my last boat and have been dreading the day i would have to do them again. How is the bravo 3 compared to alpha one gen 1?

Run it and see if the U joints are needed after. Could do them all and just run next year. Don't forget to grease the coupler

Exhaust shutters are ITEM 7 and are under the elbow

So they fell down through the exhaust into the drive? Any chance something else is in there stuck somewhere?

 

[timharper89]

Ayuh,..... The u-joints can be replaced, without changing the entire assembly,..... You'll probably find tiny ridges on the crosses when you push 'em apart, regardless how smooth the feel when assembled,...

Both the u joints and gimbal feel buttery smooth, but clearly one of them is not if I am getting the growling described, right?

The shutters live at the top of the y-pipe, just after the risers,....

Sounds like a fun job. Any chance there is more stuck in the exhaust? How would I know?

 

[timharper89]

Agreed I had pretty deep ridges on the u joints for my Alpha gen 2 but they felt smooth by hand.

They do feel smooth

To the OP you can usually cross those U joints with an automotive one. I don't know the cross for bravo U joints but the ones with internal retaining rings for a alpha one are a moog 315G or equivalent. Maybe you can match them up.

How do you"match them up"? Take them out and go to the auto parts store?

Also with that much corrosion you may have rust on the yoke where the drive input shaft goes

Assuming i would have to take the giant castle nut off to check this...

 

[alldodge]

Replacing bellows on a Bravo is pretty much the same as the Alpha

With a B3 I would use an exhaust tube instead of the exhaust boot. It's easier to put on but also will be a bit louder when running. The B3 doesn't have much of an opening for exhaust due to twin props.

Need to remove the exhaust elbows and boots to see what is left of the shutters. May also find other parts inside exhaust Y pipe. The shutters may have fallen out of the exhaust on to top of drive when drive was removed. If they were there before drive was removed then the exhaust boot is torn

 

[Candy Gramformongo]

Regarding the u-joints, isn't that just surface rust on the outside, where it doesn't matter? A little rust on the outside doesn't tell you anything about the parts inside that rotate relative each other and are supposed to coated in grease. Unless they are well-painted, steel parts will look like this after 30+ years out in the open, right?

If I saw u-joints like this in an automotive driveshaft situation, I wouldn't think it indicative of a problem.

 

[Scott Danforth]

Regarding the u-joints, isn't that just surface rust on the outside, where it doesn't matter? A little rust on the outside doesn't tell you anything about the parts inside that rotate relative each other and are supposed to coated in grease. Unless they are well-painted, steel parts will look like this after 30+ years out in the open, right?

If I saw u-joints like this in an automotive driveshaft situation, I wouldn't think it indicative of a problem.

except that in the marine environment, rust like this travels, then takes out the input shaft seal, causing a drive failure. This is why pulling the drive for inspection of u-joints, bellows and gimbal bearings is listed as every 50 hours of operation, or annually. which ever occurs first.

 

[Candy Gramformongo]

except that in the marine environment, rust like this travels, then takes out the input shaft seal, causing a drive failure.

Yeah, never of rust travelling, but if you did get a spot of it close to the sealing surface of the yoke, eventually it would grow into and compromise the seal. The OP should inspect this area and treat any rust spots that are too close, but otherwise rust on the u-joints is no big deal and certainly not a reason to replace them.

 

[Scott06]

They do feel smooth

How do you"match them up"? Take them out and go to the auto parts store?

Assuming i would have to take the giant castle nut off to check this...

Yeah mine felt smooth but when I took the out the cross looked like this one one or two of the crosses on each joint. Some of the grease looked ok on the crosses that were not roached , the ones that were roaches the grease was dark…so much for permalube …

by match them up you can take them out or measure them to size up replacements. Mine said GKN 114 or something like that cast into the joint cross. This lead to a whole bunch of options As same joint was used on RWD Volvo drive shafts for like 40 years … bottom line there are not that many u joint sizes that have been made ever… they match up what is your drive serial number ? On the alphas inside retaining rings match to moog 315 g , the outside ones I mentioned match moog 344. I was able to find a good spicer equivalent for like $30 each

yes to check drive shaft yoke castle nut needs to come off sort of. You can look in with a flash light and also drain the drive and pressure test . If it holds pressure leave it alone for now

 

[tank1949]

If you have all bellows off, check for excessive corrosion around lips. Rainwater or sea spray may be getting past hatch lip and dripping down on shaft and getting past internal transom seal. I have had that happen to me.