How often should a bellows kit be changed on a bravo leg

jamie langstone

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My boat last had a bellows kit and a gimbal bearing changed in january 2012 when would all recommend a new kit. I checked this year in January and there was no signs of wear on the bellows and the gimbal bearing was fine.
Thanks in advance.
 

rafiki_

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My boat last had a bellows kit and a gimbal bearing changed in january 2012 when would all recommend a new kit. I checked this year in January and there was no signs of wear on the bellows and the gimbal bearing was fine.
Thanks in advance.
If you have checked the bellows and they appear ok, no sign of brittleness/cracks etc, then should be OK. Mine did 4 years between changes, but I was on freshwater.
 

julians

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I thought the official recommendation from Mercruiser was every other year, that how often I changed mine on my alpha drive on my last boat. This is assuming the boat is kept in the water, if its on a trailer most of the time then I guess you could get several years out of them
 
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Beamishken

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Every 2 years is the recommendation but in reality much longer is possible

only problem I could see in leaving them is if the boat sinks due to a split bellows then it gives the insurance co a get out clause

in reality the boat only lets water in slowly due to split bellows as the water has to get through the bearing seals once through the bellows so the boat would only be letting water in slowly so pumps would cope for quite a while

I guess it depends how much you want to push your luck I think I change my last set at 4 years
 

volvopaul

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Every 2 years is the recommendation but in reality much longer is possible

only problem I could see in leaving them is if the boat sinks due to a split bellows then it gives the insurance co a get out clause

in reality the boat only lets water in slowly due to split bellows as the water has to get through the bearing seals once through the bellows so the boat would only be letting water in slowly so pumps would cope for quite a while

I guess it depends how much you want to push your luck I think I change my last set at 4 years

If the drive bellows splits it only allows a very small amount of water in as there is a drilling in the shield to allow water into the boat, this should then ring alarm bells to the owner there is a problem.

Most merc engined boats sink due to failure of the gearshift cable bellow because it has a one inch hole in the shield, when the clip fails which the merc one corrodes away after less than 12 months it relies on the elasticity of the bellow to keep the water at bay, lifting or trimming the leg then exaggerates this causing a leak, then onward failure of the cable bellows sinks the boat. In my view the clips should be examined every year, certainly the shift cable bellow clip changed every year, the merc supplied one is a pile of rubbish as its a mild steel crimp type clip which I never fit a fact I know they don't last, I fit a stainless clip of worm type drive. At least Volvo don't practise this kind of trick even if they let themselves down in other areas.
 

oGaryo

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agree regarding the clips (the do rust), I change them every year on my VP drives and inspect the bellows. I changed clips and bellows at the start of this season
 

AndieMac

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If the drive bellows splits it only allows a very small amount of water in as there is a drilling in the shield to allow water into the boat, this should then ring alarm bells to the owner there is a problem.

Most merc engined boats sink due to failure of the gearshift cable bellow because it has a one inch hole in the shield, when the clip fails which the merc one corrodes away after less than 12 months it relies on the elasticity of the bellow to keep the water at bay, lifting or trimming the leg then exaggerates this causing a leak, then onward failure of the cable bellows sinks the boat. In my view the clips should be examined every year, certainly the shift cable bellow clip changed every year, the merc supplied one is a pile of rubbish as its a mild steel crimp type clip which I never fit a fact I know they don't last, I fit a stainless clip of worm type drive. At least Volvo don't practise this kind of trick even if they let themselves down in other areas.

This is good information VP, thanks for posting.
 

Beamishken

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Most merc engined boats sink due to failure of the gearshift cable bellow because it has a one inch hole in the shield, when the clip fails which the merc one corrodes away after less than 12 months it relies on the elasticity of the bellow to keep the water at bay, lifting or trimming the leg then exaggerates this causing a leak, then onward failure of the cable bellows sinks the boat. In my view the clips should be examined every year, certainly the shift cable bellow clip changed every year, the merc supplied one is a pile of rubbish as its a mild steel crimp type clip which I never fit a fact I know they don't last, I fit a stainless clip of worm type drive. .

I prefer to use a plastic tie wrap on the outer end of the cable bellows & the inner end is glued on as well as hose clipped so even if the ss clip corrodes the glue should hold the bellows in place. never had a problem in 10 years fitting like that
 

aquapower

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The longer they are left the more difficult they can be to dismantle as corrosion will take place and only gets worse with time. If you change them every 2 years as recommended then at least everything gets a good inspection at the same time.
 
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