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Help diagnose Bravo 1, Neutral and Reverse work, forward does not

J

jlrosine

New member
Hi all. I have the following issue.

2000 year boat

5.7L merc engine

Bravo 1 outdrive

The boat will shift fine to reverse/neutral but not forward.

Here are the list of symptoms/dealer notes from the most recent issues with the out drive.

DRIVE INSPECTION
REMOVE DRIVE
INSPECT BELLOWS
INSPECT GIMBLE BEARING/U JOINTS
GREASE GIMBLE BEARING/U JOINTS
CHECK ENGINE ALIGNMENT
REMOVE LOWER UNIT AND INSPECTED LINKAGE TO DETERMINE PROBLEM. FOUND THAT THE SHIFT LINKAGE IS BROKEN AND NEEDS REPLACED

REPLACED SHIFT LINKAGE AND INSPECT FROM THERE.
INSTALLED SHIFT LINKAGE KIT
REVERSE, NEUTRAL WORK FINE, STILL NO FORWARD

RECOMMEND REPLACE ENTIRE DRIVE SHAFT HOUSING

It seems to me that they stopped troubleshooting a bit too early to just throw their hands up and say buy an entirely new upper housing?

Wondering what you mercruiser guys might do next to troubleshoot?

I'm thinking about attempting to fix this Bravo 1 on my own, either a rebuild or buying a reman'd upper. Wondering if anyone here has any recommendations on what to troubleshoot next.

Any help is much appreciated.
 
Almost positive the volvo one is identical to merc.without pics and a visual inspection impossible to answer about wear
s-l225.webp
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s-l225.webp
 
Bt Doctur said:
Almost positive the volvo one is identical to merc.

Similar, but not the same.



without pics and a visual inspection impossible to answer about wear

s-l225.webp
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s-l225.webp
Click to expand...


The Merc sliding sleeve is steel, and it is likely coated similar to the later Volvo Penta steel sliding sleeves.
These cannot be successfully lapped into the gear cups. (has to do with the coating)

The all bronze sliding sleeve is early Volvo Penta.
These can be successfully lapped into the gear cups as to remove any glazing.


.
 
Is there a digital manual/diagram for a Bravo 1 upper online? Struggling to find anything, maybe I'll have to buy a manual I just hate waiting.
 
It is time for a new cone clutch, that is the issue.... Problem is unless your find the NLA clutch your drive has, you will have to replace the upper gear set.

It may be cheaper for you to find a used working drive if the gear set and clutch are not available.
 
Docksidemarineservices said:
It is time for a new cone clutch, that is the issue.... Problem is unless your find the NLA clutch your drive has, you will have to replace the upper gear set.

It may be cheaper for you to find a used working drive if the gear set and clutch are not available.
Click to expand...

Do you think there's some chance that it's something else other than clutch? It didn't happen under load, was just pulling away from dock and no forward...but reverse/neutral are there.

The shift linkage was broken. Could it also be an issue with control box? it has has the notorious merc 3000.

I see you are certified would love any extra troubleshooting tips. Is there anything else I can diagnose before dropping gobs of money on a new upper? The gear kits I have priced are about $1000 for the entire kit, then I'll have tons of labor/new tool purchases etc.

If I buy a full new drive it's about $4500...

Are the non merc brand drives any good/trustworthy? I think I saw one for $1500 full assembled upper replacement.
 
.................
jlrosine said:
Do you think there's some chance that it's something else other than clutch? It didn't happen under load, was just pulling away from dock and no forward...but reverse/neutral are there.
You first need to understand how the cone clutch system works.
Nut shelling this:
.... the 2 upper unit driven gears rotate when the engine is running.
.... each of these 2 gears have a sliding sleeve "cup" attached to them.
.... the actual sliding sleeve is stationary at this time.
.... the sliding sleeve glides on a steep spiral cut vertical shaft spline affair.
.... the sliding sleeve is either lowered or raised into the corresponding spinning gear cup.
.... as the sleeve makes initial contact with the gear cup, friction is generated.
.... the oiling groves (in the sliding sleeve) prevent quick lock-up, allowing for a smooth engagement .... i.e., lock-up.
.... as this occurs, the oil film dissipates causing the friction to increases until full lock-up is achieved.

I can't speak directly for the Merc B drive system, but with the Volvo Penta system, if the oiling groves become contaminated with metallic debris, the debris will prevent the necessary initial friction.
With the Volvo Penta sliding sleeve, the debris can be cleared from the oiling groves, which in most cases it will renew cone clutch action.

When you pull this apart, you you will be able to examine the sliding sleeve oiling groves.


The shift linkage was broken. Could it also be an issue with control box? it has has the notorious merc 3000.
Make sure that the throttle/shift unit is offering full cable travel at the upper gear unit's sliding sleeve shift mechanism.


Are the non merc brand drives any good/trustworthy? I think I saw one for $1500 full assembled upper replacement.
You may have seen the SEI drive, of which is a Dog Clutch A drive alternative.
I don't think that SEI does the Bravo drive replacement.
Click to expand...
 
jlrosine said:
Do you think there's some chance that it's something else other than clutch? It didn't happen under load, was just pulling away from dock and no forward...but reverse/neutral are there.

The shift linkage was broken. Could it also be an issue with control box? it has has the notorious merc 3000.

I see you are certified would love any extra troubleshooting tips. Is there anything else I can diagnose before dropping gobs of money on a new upper? The gear kits I have priced are about $1000 for the entire kit, then I'll have tons of labor/new tool purchases etc.

If I buy a full new drive it's about $4500...

Are the non merc brand drives any good/trustworthy? I think I saw one for $1500 full assembled upper replacement.
Click to expand...

Pull the cable off the shift plate from the control box and shift it manually, No drive? Need a cone clutch... Find a good used drive. They go for around $1500.00 Volvo tips will not work on the Merc B drive.

You can always pull the clutch and flip it, you will just not have reverse.....
 
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Docksidemarineservices said:
Pull the cable off the shift plate from the control box and shift it manually, No drive? Need a cone clutch... Find a good used drive. They go for around $1500.00 Volvo tips will not work on the Merc B drive.

You can always pull the clutch and flip it, you will just not have reverse.....
Click to expand...

Thanks again for the responses...I really do appreciate them.

I have gone through the bravo service manual online for a tear down of the upper/rebuild, and I watched some vids. It doesn't actually look that terrible just time consuming. Seems like timing the upper/lower gears is the most important gotchya, and I need a special castle nut wrench to remove driveshaft. I suppose there are a few other special tools but nothing crazy.

You mentioned it might be really difficult to get the right clutch. Would I be able to find the right clutch match based on my upper serial number or do I need to tear it down and get the clutch out to figure that out?

My upper is: 1 65R 0L440161

I attempted to locate a clutch kit but it seems I'll have to call around....I guess it's just not common for folks to rebuild these from the look/feel of it. The dealer looked at me like I had 3 heads, they couldn't understand why I wouldn't just want to put a new upper unit on for $4500....
 
Docksidemarineservices said:
Pull the cable off the shift plate from the control box and shift it manually, No drive? Need a cone clutch... Find a good used drive. They go for around $1500.00 Volvo tips will not work on the Merc B drive.

You can always pull the clutch and flip it, you will just not have reverse.....
Click to expand...

I have talked to some service people and they think it's extremely odd that I have a 1 65R gear ratio with the 5.7L EFI.

I explained that we live at 5000ft elevation and the previous owner was very in to wake boarding/skiing.

Our family will use for tubing, some skiing/wake but it will be more all purpose for us. Should I keep the 1 65R? I suppose I can just change the prop to compensate if I keep the same ratio?
 
There is no substitute for a correct over-all gear reduction. In other words, we cannot prop ourselves out of an incorrect ratio.


As for your no FWD issue, why not pull the upper unit apart and examine the sliding sleeve? Look at the oiling groves.
 
jlrosine said:
I have talked to some service people and they think it's extremely odd that I have a 1 65R gear ratio with the 5.7L EFI.

I explained that we live at 5000ft elevation and the previous owner was very in to wake boarding/skiing.

Our family will use for tubing, some skiing/wake but it will be more all purpose for us. Should I keep the 1 65R? I suppose I can just change the prop to compensate if I keep the same ratio?
Click to expand...

If you are at higher elevation then yes this is likely the correct ratio. How does it perfomr at this elevation in terms of WOT rpm. if you are hitting correct rpm it leave it alone. Is there a perfomrance issue besides the lack of going into gear you are looking to correct?

I swaped a 4.3 for a 5.0 in my 21 ft bowrider, from the factory they would have been equipped 1.81 and 1.62 ratios drives respectively. I kept the 1.81 drive with the 5.0 and went from a 19" pitch prop to a 21" works perfectly. I doubt you can prop around several gear ratios steps, but it is likely the manufacturers use the ratios to keep all boat, engine, and usage combos in the typical 17"-21" pitch range
 
RicardoMarine said:
There is no substitute for a correct over-all gear reduction. In other words, we cannot prop ourselves out of an incorrect ratio.


As for your no FWD issue, why not pull the upper unit apart and examine the sliding sleeve? Look at the oiling groves.
Click to expand...

I've got the outdrive off the boat now and the back of the outdrive off. I can see the shift linkage/fork. I was trying to avoid taking it down further as it requires more special tools that I don't have (larger castle nut wrench etc.).

I suppose there's probably no other way to look/find root cause other than tearing down more?
 
Well I took apart the upper and got down to the clutch. It looks like the forward gear (back side) and forward side of the clutch had a white area and was slightly worn, but didn't look horrible to me, I'm surprised this would cause it to not shift in to forward.

I decided to try something I read somewhere else. I took the reverse gear and reverse side of clutch, reinstalled everything with those on the forward side. I also sanded slightly the clutch on the side that was more worn for reverse.

Got it all back together, now I just have to get the outdrive on the boat to see if it'll engage forward.

I have a remanufactured upper on the way so I might still just install that, but this was a fun little learning experience. Everything inside looked great, nothing broken, just a tiny bit of wear to be expected after 20yrs.
 
RicardoMarine said:
There is no substitute for a correct over-all gear reduction. In other words, we cannot prop ourselves out of an incorrect ratio.


As for your no FWD issue, why not pull the upper unit apart and examine the sliding sleeve? Look at the oiling groves.
Click to expand...

There is no repair for this besides changing the cone clutch. This is not a Volvo drive.
 
jlrosine said:
Well I took apart the upper and got down to the clutch. It looks like the forward gear (back side) and forward side of the clutch had a white area and was slightly worn, but didn't look horrible to me, I'm surprised this would cause it to not shift in to forward.

I decided to try something I read somewhere else. I took the reverse gear and reverse side of clutch, reinstalled everything with those on the forward side. I also sanded slightly the clutch on the side that was more worn for reverse.

Got it all back together, now I just have to get the outdrive on the boat to see if it'll engage forward.

I have a remanufactured upper on the way so I might still just install that, but this was a fun little learning experience. Everything inside looked great, nothing broken, just a tiny bit of wear to be expected after 20yrs.
Click to expand...


The shiny area on the clutch is wear. Flipping the clutch over will give you drive and you will lose reverse. Sanding the clutch will ruin it further. Replacement is the only fix. You can still find the clutch through the NLA locator. There are some out there to buy if you want to repair the upper.

As for the gear ratio and High Altitude, if it ran fine for all these years it will work for you too.
 
.............
jlrosine said:
well i took apart the upper and got down to the clutch. It looks like the forward gear (back side) and forward side of the clutch had a white area and was slightly worn, but didn't look horrible to me, i'm surprised this would cause it to not shift in to forward.
the slightest amount of debris or glazing will prevent the necessary friction (between the cup and sleeve) from occurring.
No friction = no eventual lock-up or engagement.

i decided to try something i read somewhere else. I took the reverse gear and reverse side of clutch, reinstalled everything with those on the forward side. I also sanded slightly the clutch on the side that was more worn for reverse.
if you flipped these gears from top to bottom and visa-versa, you would want to check the gear pattern.
Click to expand...


chris said:
rick said:
as for your no fwd issue, why not pull the upper unit apart and examine the sliding sleeve? Look at the oiling groves.
Click to expand...
there is no repair for this besides changing the cone clutch. This is not a volvo drive.

Understood.
Click to expand...
the shiny area on the clutch is wear. Flipping the clutch over will give you drive and you will lose reverse.

Sanding the clutch will ruin it further.
Click to expand...
no one suggested sanding the surface.
as mentioned, the volvo penta bronze sliding sleeve can be lapped into the corresponding gear cup....... But we do not lap the steel sliding sleeve due to the coating.
Apparently the merc b drive sliding sleeve cannot be lapped either.......... Or merc simply wants to sell parts!
Click to expand...

replacement is the only fix. You can still find the clutch through the nla locator.
Click to expand...
to the best of my knowledge, there is no single "cone clutch" component.
the cone clutch is the sum of all components..... I.e., the driven gears and gear cups, the sliding sleeve, the steep spiral cut splines on the vertical shaft, etc.

if merc calls the sliding sleeve a "clutch", then they were not paying attention when they gained the rights to copy volvo penta's cone clutch design!
Click to expand...


there are some out there to buy if you want to repair the upper.
Click to expand...
if this is referring to the sliding sleeve, what about the gear cups that may be glazed?
Click to expand...


.
 
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RicardoMarine said:
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.
Click to expand...

Well thanks fellas.

I flipped the clutch/gears and reinstalled. I had to adjust the shift cable slightly but I now have both forward and reverse. I tested quite a few times and it always hits neutral, and always hits F and R.

I think I'm finally going to do a lake test tomorrow then decide what to do. I have a new "upper" that cost me quite a bit that will be here on Wednesday. I'm trying to decide, I might keep it as a fully reconditioned backup, or I might just order a clutch/gear as a replacement and redo the internals again when the time comes.

I really appreciate the help, you guys are great!
 
jlrosine said:
Well thanks fellas.

I flipped the clutch/gears and reinstalled. I had to adjust the shift cable slightly but I now have both forward and reverse. I tested quite a few times and it always hits neutral, and always hits F and R.

I think I'm finally going to do a lake test tomorrow then decide what to do. I have a new "upper" that cost me quite a bit that will be here on Wednesday. I'm trying to decide, I might keep it as a fully reconditioned backup, or I might just order a clutch/gear as a replacement and redo the internals again when the time comes.

I really appreciate the help, you guys are great!
Click to expand...

Well, just flipping the clutch is what I have done in the past, not the gears too. As for adjusting the cable, I suggest you get the tools to set that cable up correctly before you damage the ramp.
 
................

jlrosine said:
................or I might just order a clutch/gear as a replacement and redo the internals again when the time comes.

Hypoid gears are machined/manufactured at a set. We cannot simply purchase one gear!
Click to expand...


Chris said:
Well, just flipping the clutch is what I have done in the past, not the gears too.
Apparently jlrosine (the OP here) does not understand that the drive gear and the two driven gear tooth patterns have been set at the factory.
Flipping the two driven gears around may change the gear pattern and lead to premature wear and failure.


Again this is not a Volvo... Clutch is not Bronze. No Lapping.

Please re-read my posts.
I am fully aware that the B drive sliding sleeve cannot be lapped into the gear cups. No where does Merc suggest this!

However, there is nothing that would prevent us from looking at the oiling groves for metallic debris, and clearing them out!


Merc B drive cone clutch components.jpg
Click to expand...


 
New clutch just installed 0 time on it, My question is when I shift n to f or n to rev, it free wheels its like it needs to be turning to enguage?
Is this normal? Used book and on line no problems found, Thanks for yer help.
 
Cone clutch shifting must occur when running. it not working because there is no friction between cones..
 
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