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Bravo 3 squeak/rattle

Is that thru transom or thru prop exhaust?

If thru prop it could be exhaust flappers.

Otherwise I would suggest remove outdrive, check bearing with fingers for smoooth rotation and check ujoints to see if they may have an issue
 
Is that thru transom or thru prop exhaust?

If thru prop it could be exhaust flappers.

Otherwise I would suggest remove outdrive, check bearing with fingers for smoooth rotation and check ujoints to see if they may have an issue

yes, it is a thru prop exhaust. I will check that, thanks.
 
Thanks. I noticed that at least the squeak was still there when it was in gear. I didn’t pay attention to see if the rattling was still there while in gear.
 
Thanks. I noticed that at least the squeak was still there when it was in gear. I didn’t pay attention to see if the rattling was still there while in gear.

Jatsie

My BIII is making the exact same noise. I assume its the drive anyways. Before starting up the boat, I did change the out drive oil

I pulled my drive yesterday and ujoints look great, gimble looks great. I need to make a very slight adjustment to engine alignment.

Did you ever figure out this noise?

Thanks

Aaron
 
I did find the thrust washer worn (Mercruiser 12-41613). I replaced this washer along with the yoke locknut (Mercruiser 11-22339) and set the bearing preload at around 6 in/lbs. I did find that the bearing spacer gave me a little trouble staying centered, so I removed the gearset from the top of the drive, and temporarily installed the bearing/yoke assembly in the drive and tightened the locknut enough to keep the spacer from moving. Then, took it back to the bench to set the preload.
This appeared to solve the rattling, but after about 15 minutes of running on the "muffs", the squeak is still there. I haven't had a chance to test it on the water yet.

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Jatsie

My BIII is making the exact same noise. I assume its the drive anyways. Before starting up the boat, I did change the out drive oil

I pulled my drive yesterday and ujoints look great, gimble looks great. I need to make a very slight adjustment to engine alignment.

Did you ever figure out this noise?

Thanks

Aaron
 
I did find the thrust washer worn (Mercruiser 12-41613). I replaced this washer along with the yoke locknut (Mercruiser 11-22339) and set the bearing preload at around 6 in/lbs. I did find that the bearing spacer gave me a little trouble staying centered, so I removed the gearset from the top of the drive, and temporarily installed the bearing/yoke assembly in the drive and tightened the locknut enough to keep the spacer from moving. Then, took it back to the bench to set the preload.
This appeared to solve the rattling, but after about 15 minutes of running on the "muffs", the squeak is still there. I haven't had a chance to test it on the water yet.

Thanks for the reply. Bummed to hear the squeak is still there. Does the play in your gears look like this? https://www.youtube.com/watch?v=feD8o8fhF5k&ab_channel=ravan999

While not my video, I did pull my top cover and my play is similar to the video. Everything looked good but I have nothing to compare it to in order to say if its good or not.
 
Mine did appear to quiet down after the thrust washer replacement. I noticed some small amount of play in the pinion yoke due to this washer. If I held the gear, and slowly rocked the driveshaft back an forth, it seemed loose, so I dug in further and bought the tool to remove the ring nut.


Thanks for the reply. Bummed to hear the squeak is still there. Does the play in your gears look like this? https://www.youtube.com/watch?v=feD8o8fhF5k&ab_channel=ravan999

While not my video, I did pull my top cover and my play is similar to the video. Everything looked good but I have nothing to compare it to in order to say if its good or not.
 
That is a great idea. Unfortunately, I didn’t run the engine with the drive off. Hopefully all goes well this weekend. I will run it without the drive next time I have it off.

How was your engine alignment? Did you try running the boat with out the drive connected?
 
Ran the boat with no drive, zero noise. Coupler looked good and alignment checks out good.

I pulled the top cap again on the drive. Decided to measure the oil level. It was roughly 1/2 inch below the vent hole. Took 250cc of oil to bring it to the vent hole.

I talked to George at All American Drive Service. He said the drive oil should be 1 1/4 to 1 1/2 inches above the vent plug.

Whats ODD is a couple weeks prior I had changed the drive oil, pump from the bottom until oil came out the vent, put the plug in and continued pump until oil was present in the monitor. Since the gear lube oil chance, I haven't started the boat until this weekend. I'm wondering if this was the noise/issue?

Have you recently changed your gear oil?

He also seems to think based on your video that your ujoints are starting to go.
 
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With regards to oil level,

If you have a engine/transom mounted gear lube reservoir your gear oil level will be far above vent screw.
If you do not have reservoir and you fill to vent hole level it is difficult to achieve much higher level. It can be done but service manuals always said "until oil seeps out of vent hole".

One thing to consider.
The shift linkage in upper gear case will rattle so you may want to look at those parts.
 
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Thanks, that’s interesting on the oil level. I have a reservoir tank in the engine compartment which I would guess would keep the level higher than the vent hole.
I have replaced my u-joints and shaft as an assembly as well as the gimbal bearing, so I should be good there. I think I will check my engine alignment next time I pull the out drive off.

Ran the boat with no drive, zero noise. Coupler looked good and alignment checks out good.

I pulled the top cap again on the drive. Decided to measure the oil level. It was roughly 1/2 inch below the vent hole. Took 250cc of oil to bring it to the vent hole.

I talked to George at All American Drive Service. He said the drive oil should be 1 1/4 to 1 1/2 inches above the vent plug.

Whats ODD is a couple weeks prior I had changed the drive oil, pump from the bottom until oil came out the vent, put the plug in and continued pump until oil was present in the monitor. Since the gear lube oil chance, I haven't started the boat until this weekend. I'm wondering if this was the noise/issue?

Have you recently changed your gear oil?

He also seems to think based on your video that your ujoints are starting to go.
 
Engine alignment would not be the cause of your issue (outdrive rattle).

If out of alignment enough it could cause premature gimbal bearing failure or engine coupler failure.

With a reservoir models, you fill out drive to vent screw. Make sure reservoir is full to line, Run engine and a couple ounces will drain into drive over time virtually filling it. Then refill reservoir. Monitor reservoir for loss of level from there on and if level drops significantly, leak is present somewhere.


""""Whats ODD is a couple weeks prior I had changed the drive oil, pump from the bottom until oil came out the vent, put the plug in and continued pump until oil was present in the monitor.""""


Do not read this (Large blue type) and think it is correct. It is not. What I typed above blue is the process. You do NOT back fill Reservoir!!!!
 
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Thank you. I believe the rattle has been fixed with the thrust washer replacement. I am now more concerned with the squeak/chirping from the top of the drive. It takes about 15 minutes of running on the muffs until I can hear it. It happens, both in and out of gear.


Engine alignment would not be the cause of your issue (outdrive rattle).

If out of alignment enough it could cause premature gimbal bearing failure or engine coupler failure.

With a reservoir models, you fill out drive to vent screw. Make sure reservoir is full to line, Run engine and a couple ounces will drain into drive over time virtually filling it. Then refill reservoir. Monitor reservoir for loss of level from there on and if level drops significantly, leak is present somewhere.
 
With a reservoir models, you fill out drive to vent screw. Make sure reservoir is full to line, Run engine and a couple ounces will drain into drive over time virtually filling it. Then refill reservoir. Monitor reservoir for loss of level from there on and if level drops significantly, leak is present somewhere.
Thank you for explaining the correct process.

Whats ODD is a couple weeks prior I had changed the drive oil, pump from the bottom until oil came out the vent, put the plug in and continued pump until oil was present in the monitor.
Do not read the (Large blue type) and think it is correct. It is not. You do NOT back fill Reservoir!!!!

I clearly did it wrong and am thankful I did not run the drive on the lake being low on oil. Thank you pointing out where I went wrong.

Thank you. I believe the rattle has been fixed with the thrust washer replacement. I am now more concerned with the squeak/chirping from the top of the drive. It takes about 15 minutes of running on the muffs until I can hear it. It happens, both in and out of gear.

Agree. I'm wonder if being low on drive oil and filling it up wrong caused this. Everything else looks great. Ill be reinstalling the drive later this week and retesting with proper fluid level!
 
Is the manual wrong?

Bravo II and III: Trim sterndrive unit to full UP/OUT position.
3. Remove sterndrive unit gear lube monitor from bracket.
4. Remove cap, empty contents of gear lube monitor into suitable container and discard.
5. Clean gear lube monitor thoroughly.
6. Return gear lube monitor to bracket. Do not refill at this time.
7. Check condition of hose and hose connections. Replace as necessary.
8. Remove sterndrive unit vent plug and fill/drain plug. Allow lubricant to drain completely.
9. If sterndrive unit is draining in full DOWN/IN position, trim to full UP/OUT position after draining drain any remaining oil from internal driveshaft housing ledges.
10. Trim sterndrive unit to full DOWN/IN position (with anti-ventilation plate level) to complete draining process.
11. Using lubricant pump, fill sterndrive unit through fill/drain hole with lubricant until oil is even with bottom edge of vent hole.
12. Without removing lubricant pump fitting from fill/drain hole, reinstall oil vent plug and sealing washer. Torque to 40 lb-in. (4.5 Nm).
13. Continue filling drive until there is one inch of oil in the gear lube monitor.

14. Remove lubricant pump fitting and quickly reinstall fill/drain plug and sealing washer.
15. Fill gear lube monitor to FULL line on decal.
16. Ensure rubber seal is in place on gear lube monitor cap.
17. Install gear lube monitor cap.
18. Check oil level in gear lube monitor.
19. Recheck oil level after first use.
 
I am OLD school and after filling thousands of outdrives with gear oil I am telling you my opinion on how to do it so you dont make a mistake.

If you choose to follow the manual please do. If you want to hand pump from a quart bottle to back fill the reservoir thats fine.



Bravo outdrives are very susceptible to heat, Far more susceptible than Alpha drives. Many Bravo drive boats run drive showers to cool upper gear case.

So being low on gear oil can increase the upper gear case chances of over heating leading to failure.
 
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