AD31 Bellows replacement

[tangerine]

I have always replaced my genuine Volvo exhaust, drive and water bellows bi-annually for years. each time the old bellows have appeared in unblemished condition. Am I being too careful or could I leave them on for longer. My boat is in salt water in Devon.

 

[spannerman]

If it was a Mercruiser then you change every 5 yrs, but Volvo uses much thinner rubber so 2 yrs is long enough, you don’t need to change the exhaust bellows so often as these are not critical. Whereas the driveshaft bellows are critical, I always view it as cheap insurance as if they leak it can be expensive,, at the least a new U/J, at worst water gets into the drive and the intermediate shaft bearings. I have repaired dozens of VP drives because of this.

 

[tangerine]

I have always replaced my genuine Volvo exhaust, drive and water bellows bi-annually for years. each time the old bellows have appeared in unblemished condition. Am I being too careful or could I leave them on for longer. My boat is in salt water in Devon.

If it was a Mercruiser then you change every 5 yrs, but Volvo uses much thinner rubber so 2 yrs is long enough, you don’t need to change the exhaust bellows so often as these are not critical. Whereas the driveshaft bellows are critical, I always view it as cheap insurance as if they leak it can be expensive,, at the least a new U/J, at worst water gets into the drive and the intermediate shaft bearings. I have repaired dozens of VP drives because of this.

Thanks for your observation Spannerman, I will continue as always I think and change bi-annually.

 

[volvopaul]

Thanks for your observation Spannerman, I will continue as always I think and change bi-annually.

I’d agree with SM , exhaust bellows last for years , it’s the clips that rot away .
The other reasons I’ve find over the years not to change exhaust bellows is when they are removed from the drive as they shrink making it difficult to get one end back on the drive .

The latest water hose clips from Volvo at over £8 plus vat act like an anode , fit a stainless one from the chandlery .

 

[sogood]

I have always replaced my genuine Volvo exhaust, drive and water bellows bi-annually for years. each time the old bellows have appeared in unblemished condition. Am I being too careful or could I leave them on for longer. My boat is in salt water in Devon.

I would err on the side of caution. Having experienced corrosion on an alpha leg in saltwater, the bellows wasn't so much the problem, as the transom assembly and the leg itself. Corrosion had eaten away the material on both ends that the bellows clips onto. I think the volvo outdrive is much more substantial with a better more solid lip for hooking the bellows onto. Regular inspection is the key!

 

[Momac]

................ each time the old bellows have appeared in unblemished condition.

What does that tell you?
Some Volvo Penta service recommendations do seem somewhat conservative.

 

[Boat2016]

What does that tell you?
Some Volvo Penta service recommendations do seem somewhat conservative.

You have the choice...if you think you know better than the recommended service schedule you can of course do it how you feel it should be done...I guess it all depends how you use your boat and if pottering up river is all you do then the rick is minimal, however if you do many sea miles then perhaps I would look at it differently.

 

[Boat2016]

If it was a Mercruiser then you change every 5 yrs, but Volvo uses much thinner rubber so 2 yrs is long enough, you don’t need to change the exhaust bellows so often as these are not critical. Whereas the driveshaft bellows are critical, I always view it as cheap insurance as if they leak it can be expensive,, at the least a new U/J, at worst water gets into the drive and the intermediate shaft bearings. I have repaired dozens of VP drives because of this.

I know an engineer that swears about Mercruiser and said he would rather do VP any day as they tend to come apart easier and don’t get so many issues from leaving too long, perhaps that’s the difference in leaving 5 years instead of 2.

 

[Momac]

You have the choice...if you think you know better than the recommended service schedule you can of course do it how you feel it should be done...I guess it all depends how you use your boat and if pottering up river is all you do then the rick is minimal, however if you do many sea miles then perhaps I would look at it differently.

That's right.
My boat is on fresh water and I do spend a lot of time on the river.

If bellows come off looking like new after two years does that not suggest they have significant remaining life ?

 

[Boat2016]

That's right.
My boat is on fresh water and I do spend a lot of time on the river.

If bellows come off looking like new after two years does that not suggest they have significant remaining life ?

i expect a bellow to still be in good order when it’s removed...it’s no good leaving them on until they have perished as the damage is most likely done then, fitting a new one tells me that I should be safe for the next 2 years then....or am I missing something here ?

 

[spannerman]

i expect a bellow to still be in good order when it’s removed...it’s no good leaving them on until they have perished as the damage is most likely done then, fitting a new one tells me that I should be safe for the next 2 years then....or am I missing something here ?

Exactly right, you are buying peace of mind for the next few years assuming everything else is in good order. I have changed over 2.000 bellows in the past 24 years, and the vast majority of problems have been with Volvo drives, water in the bellows requiring new U/J’s , bearings etc. I have had the same fault on Mercruisers also but only a fraction due to a much better quality bellows. If a boat had a twin installation more often than not one side had water ingress. I accept that Volvo is more common but even so they have a higher failure rate in my experience. Mercruiser bellows will easily go past the 5 yr change interval as I have had many in that have been on for 7-8yrs! But go past 2 yrs with Volvo and you are taking a big chance. All IMHO.

 

[CLB]

I change my VP bellows every two years and, like others, they come off looking very serviceable. One time, due to personal reasons, I left it three years. The bellows still looked the same, ie perfectly serviceable and easily capable of another year. These were genuine VP bellow BTW.

I still change every two years, but wouldn't fret if I had to leave it another year having seen what three years looks like.

 

[QBhoy]

I know an engineer that swears about Mercruiser and said he would rather do VP any day as they tend to come apart easier and don’t get so many issues from leaving too long, perhaps that’s the difference in leaving 5 years instead of 2.

I’d maybe argue with that one. Although I have no doubt my VP outdrives in the past are better engineered than your average mercruiser. There is no way a stubborn 290DP is easier to remove than a mercruiser alpha one is. The latter is a 20 minute job if familiar. The 290 not so much. Especially if those pins have been in a while

 

[Greg2]

Exactly right, you are buying peace of mind for the next few years assuming everything else is in good order. I have changed over 2.000 bellows in the past 24 years, and the vast majority of problems have been with Volvo drives, water in the bellows requiring new U/J’s , bearings etc. I have had the same fault on Mercruisers also but only a fraction due to a much better quality bellows. If a boat had a twin installation more often than not one side had water ingress. I accept that Volvo is more common but even so they have a higher failure rate in my experience. Mercruiser bellows will easily go past the 5 yr change interval as I have had many in that have been on for 7-8yrs! But go past 2 yrs with Volvo and you are taking a big chance. All IMHO.

Do you think that the 2 year interval applies even if the boat spends each winter out of the water? Only asking out of curiosity because I still do it to the recommended schedule for the reasons you cite.

 

[spannerman]

Here in Norway most boats get put ashore for winter and the dealers still use the two year interval, when its in the water you have the possibility of water ingress and when its on land for 6-7 months the rubber dries and gets brittle unless you spray it with silicone. The other problem when they stay in the water is barnacles can grow on the bellows and then cut it when the steering is operated. One guy I knew changed his VP bellows before winter and the boat was in a freshwater creek which got surface ice exactly at the level of the bellows which damaged them causing a leak, Some people never encounter a leak and some religiously follow the maintenance schedule and still are unlucky. Its just a risk you have to live with when you own an outdrive. I once lifted my boat for a midseason pressure wash and saw that the 4 mth old original Mercruiser hose clip holding the bellows to the transom had rusted through despite having a grounding wire, I pulled the drive washed off the small amount of saltwater and sprayed the U/J and fitted a new clip and got away with no damage.

 

[spannerman]

I’d maybe argue with that one. Although I have no doubt my VP outdrives in the past are better engineered than your average mercruiser. There is no way a stubborn 290DP is easier to remove than a mercruiser alpha one is. The latter is a 20 minute job if familiar. The 290 not so much. Especially if those pins have been in a while

I’d sack you if you used 20 min to remove an Alpha drive... only joking! howeverare a Mercruiser dealer and none of the 4 of us in the workshop use more than 5 min to remove any type of Mercruiser drive.

 

[QBhoy]

I’d sack you if you used 20 min to remove an Alpha drive... only joking! howeverare a Mercruiser dealer and none of the 4 of us in the workshop use more than 5 min to remove any type of Mercruiser drive.

Haha. Maybe I was being conservative at the measure of not sounding ridiculous. I’m you getting my point though. Yeah. They come off real quick. I’m only once every year removing. Go easy on me !