Just Replaced Gimbal Bearing, Still Making a Noise?

[San_Diego_SeaRay]

Just replaced a gimbal bearing and two other people as well as I agreed the old one didn't feel bad. So I re-install the drive, and the sound didn't go away. Could it be drive shaft u- joints if I don't remember feeling any play in them? I just can't imagine what else could be making this rumbling noise.


Hopefully this video works for you (gotta click on the image in Google Photos to open the video):

https://photos.app.goo.gl/KDcBpt2kGvnC3RAw5


1993 7.4 Carb'd Bravo w. a Bravo 1
1993 Chaparral 270 Signature

 

[alldodge]

Either U joints or your engine coupler is loose

Did you check alignment before re-install?

 

[San_Diego_SeaRay]

Either U joints or your engine coupler is loose

Did you check alignment before re-install?

I did check alignment. I don't have a lot of experience here but it was easy to move the alignment tool in and out of the coupler.

I did consider it might be a loose coupler. I think I was in denial. Would pulling the gimbal bearing out and sticking the alignment tool into the coupler and checking for play be my next move?.

 

[harringtondav]

I did consider it might be a loose coupler. I think I was in denial. Would pulling the gimbal bearing out and sticking the alignment tool into the coupler and checking for play be my next move?.

I'm thinking your results will be indeterminate. ....you'll still be guessing. Also you'll need to wrap a new tolerance ring around the gimbal bearing before reinstall. Pulling your engine is the only true way to assess your coupler. And by then you may as well replace it to settle all doubts.

Before that, I'd press out the U joint on the coupler shaft and take a good look at it. Assuming they're '93 originals on what looks like big block Bravos, they could be done for. 26 yrs is a long time. If bad or iffy, replace both Unis and see if things settle down before you dig deeper.

 

[alldodge]

Don't pull the bearing back out unless you want to replace it again, no way to remove without damaging it.

As Harringtondav mentioned, pull the drive and check out the U joints real close. If you can get any slop in them, then that's the problem.

After pulling the drive, reach behind the motor and see if you can grab the coupler with something to see if it can be moved any.

Has the drive lube been changed, and if so was any metal found?

 

[San_Diego_SeaRay]

OK thanks Harringtondav and AllDodge. Lube was not changed w. the gimbal replacement. I'll have to check for shavings. We did notice that the grease on the shaft splines was a greyish color; indicating metal was in it.

I'll re-pull the drive and take a close look at those U joints. I hope that's the problem. I can fix that. Pulling an engine and replacing a coupler is going to get expensive.

 

[Rick Stephens]

I'm on the replace em team. If I heard something, I would have replaced them immediately and had a lot more confidence in a gimbal that felt fine. It is really hard to tell by hand if a u-joint is going bad. And when it comes to boats, which are always expensive to maintain, u-joints are a dirt cheap repair. I hear something like you describe, I replace em.

Rick