Bravo Knock

[krisnowicki]

I had a new to me knockish tick sound coming from the drive. I removed the drive and the sound stopped. So I know it is in the drive and not in the exhaust. \

Oil looks great no water or metal shavings. I removed the top cap and it looks awesome no missing teeth or damage. It does not change when I turn or trim the motor. How can I diagnose the knock.

2004 Bravo 1 drive

 

[HT32BSX115]

Re: Bravo Knock

Howdy,


Did the "knock" change with steering left/right or trimming up/down?

If it did, it could possibly be the U-joints and/or gimbal bearing or input bearing in the drive.

I think all these drives make some noise though and it may be "normal"..........

 

[krisnowicki]

Re: Bravo Knock

no change with the trim or steerage. could the drive start to fail with no signs in the oil....?

 

[Don S]

Re: Bravo Knock

With the drive on the boat and the engine idling, you need to use a mechanics stethoscope to determine where the knock is coming from. Upper, lower, bellhousing area. etc. It will narrow down the search considerably.

 

[krisnowicki]

Re: Bravo Knock

roger did that..... it is coming from the upper where it meets the bellhousing area. Almost like the u joint is hitting the bellows retainer sleeve. But i didnt think that was possbile

 

[krisnowicki]

Re: Bravo Knock

also shifting in and out of gear does not effect the knock

 

[HT32BSX115]

Re: Bravo Knock

also shifting in and out of gear does not effect the knock

Well, that would probably indicate that it's in the "stuff" that's always turning whether it's in gear or not......

Almost like the u joint is hitting the bellows retainer sleeve.

Or maybe a u-joint itself?

 

[krisnowicki]

Re: Bravo Knock

I am going to do the u joints tongiht... Are the u-joints for all bravos interchangable?

 

[krisnowicki]

Re: Bravo Knock

pulled the u joints.... the yoke from attached to the drive seems to be worn a bit. What would this rub? The bellows sleeve? Also, there is no rubber seal that goes around the ring nut?

 

[krisnowicki]

Re: Bravo Knock

was the coupler out of round causing a knock with the gimbal bearing

 

[HT32BSX115]

Re: Bravo Knock

was the coupler out of round causing a knock with the gimbal bearing

So, you're saying that the ACTUAL noise WAS coming from the gimbal bearing.......AND was due to the coupler being a little "OFF"?

 

[krisnowicki]

Re: Bravo Knock

coupler was out of round and causing alot of wobble. Half of the coupler was dead on alignment.. The other half slammed the shaft into something I assume the gimbal because the o ring was flattened after an hour

 

[Pete104]

Re: Bravo Knock

What part number was the replacement coupler?

 

[fishaman]

Re: Bravo Knock

coupler was out of round and causing alot of wobble. Half of the coupler was dead on alignment.. The other half slammed the shaft into something I assume the gimbal because the o ring was flattened after an hour

That is exactly what I see on my Bravo 2:

- Gimbal bearing o-rings were flattened when I took out the drive (half-moon shape instead of round in cross section)
- Irregular knocking sound from gimbal area when at idle

I checked alignment when the outdrive was off, and it looks very good, coupler splines marked the greased end of the tool very uniformly on all sides. So... do I have a worn coupler that should be replaced? That was the first time I took the outdrive off after replacing the engine 2 years ago. With the previous engine, there was some knocking sound, but I do not remember any flattened o-rings on the shaft.
Will greatly appreciate any suggestions, thanks in advance!

Alex