Volvo QL BP800 Bow Thruster Help

[kread]

Hi All, We have the above currently installed and is time for a replacement as gear box broke and lack of service parts available. I am trying to identify a direct replacement with regards to the 185 tunnel currently fitted.

My problem is until the boat is out of the water there is no way of knowing the drilling details the current tunnel has for the BP800. The manual gives the hole sizes for the center shaft and 2 bolts but does not give the distances to each other. It would be helpful to know these measurements to enable the replacement to be purchased and ready for a quick swap out.

So as anybody got this info or have a old gearbox these measurements can be taken from, or has anybody replaced a BP800 with a suitable make/model without any mods to the tunnel.

Hopefully some help is out there.

 

[Craig W]

Hi All, We have the above currently installed and is time for a replacement as gear box broke and lack of service parts available. I am trying to identify a direct replacement with regards to the 185 tunnel currently fitted.

My problem is until the boat is out of the water there is no way of knowing the drilling details the current tunnel has for the BP800. The manual gives the hole sizes for the center shaft and 2 bolts but does not give the distances to each other. It would be helpful to know these measurements to enable the replacement to be purchased and ready for a quick swap out.

So as anybody got this info or have a old gearbox these measurements can be taken from, or has anybody replaced a BP800 with a suitable make/model without any mods to the tunnel.

Hopefully some help is out there.

How did this turn out? Did you find a suitable replacement? I just bought a vessel and have the same problem.

 

[kread]

We will know within the next couple of months. We have been advised a max power is the best option but the guys who are swapping it out will not be able to tell if the mount holes are identical until the boat is out of the water.
It seems crazy that Volvo don't have a template of the hole's.

 

[Plum]

How did this turn out? Did you find a suitable replacement? I just bought a vessel and have the same problem.

You could remove the electric motor from the gearbox inside the boat to reveal the bolts that go through the tunnel and measure the spacings?

 

[kread]

Not sure as looking at bp800 installation manual there is a housing fixed to the outer tunnel. I presume removing the bolts would allow water in. Not sure just my thoughts.

 

[Plum]

Not sure as looking at bp800 installation manual there is a housing fixed to the outer tunnel. I presume removing the bolts would allow water in. Not sure just my thoughts.

Yes, don't remove the housing from the tunnel while in the water but, as the BP800 is a belt drive, you should be able to remove the belt cover (I assume you have done that already to check the belt is ok) and if necessary, remove the motor and/or toothed-wheels to expose the bolts that hold the casing to the tunnel so you can measure the bolt spacing.

 

[Plum]

Not sure as looking at bp800 installation manual there is a housing fixed to the outer tunnel. I presume removing the bolts would allow water in. Not sure just my thoughts.

I have been looking to replace a QL BP450 thruster and am also searching for the bolt spacing. I know this it not the same size as yours but I have found, in my searches, some info relating to the BP800 that may help you. First, the BP800 uses the same gear housing as the BP900 so the bolt spacing must be the same. In the forum at this link QL bow thruster parts? - Cruisers & Sailing Forums a guy called Charliemciver mentions his BP900 failed and, further down the forum, mentions he found the closest match was a Sidepower SE100/186T which I believe is this one. https://www.sleipnergroup.com/thruster-systems/thrusters/se100-tunnel-bow-stern-thruster-12v
Hope this helps, I am still searching for the BP450 bolt spacing .........

 

[kread]

Yes, don't remove the housing from the tunnel while in the water but, as the BP800 is a belt drive, you should be able to remove the belt cover (I assume you have done that already to check the belt is ok) and if necessary, remove the motor and/or toothed-wheels to expose the bolts that hold the casing to the tunnel so you can measure the bolt spacing.

Uhm not sure about the belt drive, no belt, direct drive into g/ box.

 

[Plum]

Uhm not sure about the belt drive, no belt, direct drive into g/ box.

My docs show the BP800 as a belt drive and the motor laying on its side and the BP900 a vertical direct drive.

 

[kread]

Thanks for everyone input and links.
Maybe the QL means upright motor without belt drive. When the gearbox is removed, I will try to take the measurements of the mounting holes and post on here for future reference.
Thus should help anyone with the same issue to choose a replacement bow thruster.

 

[Plum]

Thanks for everyone input and links.
Maybe the QL means upright motor without belt drive. When the gearbox is removed, I will try to take the measurements of the mounting holes and post on here for future reference.
Thus should help anyone with the same issue to choose a replacement bow thruster.

Actually, QL was a brand name Volvo Penta gave to their thrusters. From their marketing text in 2002: "Volvo Penta’s Quality Line range of marine accessories......."

 

[kread]

Uhmm quality line is very debatable, looks like there has been a huge shift to improve operation and longevity. Brushless motors no more carbon deposits around the thruster compartment. Sealed for life gearboxes and soft start to name a few, plus a better understanding of materials hopefully leading longer lasting units for all of us.

 

[shortjohnsilver]

Seen this thread today and as my VP bow thruster BP800 has developed an oil leak, I wondered whether you managed to match replace or repair your thruster.
VP part list hopeless as these became obsolete in 2012 ish.
A marine engineer is thinking replace as this will be an ongoing issue with these
units.
Ta.

 

[Plum]

Seen this thread today and as my VP bow thruster BP800 has developed an oil leak, I wondered whether you managed to match replace or repair your thruster.
VP part list hopeless as these became obsolete in 2012 ish.
A marine engineer is thinking replace as this will be an ongoing issue with these
units.
Ta.

it is highly likely that the oil seals are a standard size and can be bough for a few £s but if you are gong to pay your mechanic to strip the gearbox and fit new seals probably better to put that money towards a new thruster given the age of yours. If you are DIYing then certainly worth stripping and if everything else looks good, fit new seals.

 

[shortjohnsilver]

If I can get the port side end cap/plate off I’ll be able to draw the shaft and port side gearing out. I dont think it’s the O ring that’s failed behind the plate, I suspect the bearing/seal on the shaft has failed, leaking oil out along the shaft. I’ll have a go at these things but dont have the necessary tools/workshop/skill, so, i fear your’e right, the marine engineer is likely to suggest fitting an alternative bow thruster for the reasons you have outlined. But if I can get him to strip the shaft down and replace the bearing/seal, i would prefer to go that way and get by for a while longer.

 

[JoeBeneteauOceanis]

Hi I have exactly the same problem. Slow leak from the prop shaft on the starboard side. Actually the prop was also missing. I've taken the cap off but haven't been able to get the gear assembly apart and get access to the bearing yet. Going to soak it to loosen it. I'll send photos in another post but it actually looks like the metal on the end cap around the ring seal has been damaged somehow. Are the ring seals held in with circlips? Because mine do not have any! Have found a company in America who are manufacturing replacement parts.https://thrusterparts.com/bp1200-parts.html
Not sure if they can do a gear housing yet though. The Quick 185 DP gear box looks incredibly similar so also in contact with Andy around Solent area to see if it might be an alternative. Will keep you updated.

 

[shortjohnsilver]

I couldn’t get the port side end cap off, which I needed to do, so as to remove the port side gear shaft, where my oil leak is leaking (slowly) along.
As expected a marine engineer wasn’t prepared to do the work, without removing the gear housing leg from the tunnel entirely. It is tight in there admittedly. This would also mean removal of the drive motor too. He’s costs mounted up quickly and to the point that he said it would probably be more cost effective to replace with a vetus unit.

I’ve had the boat out of the water for a month and monitored the rate of leak and found it to be minimal. More importantly there isn’t any emulsification evident in the oil.

Obviously there is leak I suspect at the shaft seal, but to get at it, I’d need to extract the shaft fully and get it onto a work bench to dismantle properly without causing damage. Of course I’m unable to do this without fear of causing stress to the gear shaft seal to the tunnel.
So, I’m of the opinion that the water pressure is sufficient (now)to prevent the heat box oil from leaking out against the inward water pressure!
Therefore I’ve put it all back together again and relaunched.
Not ideal but I’m mid way through treatment for prostate cancer and……well……let’s see how things go over the next ten months.
It’s still fully operational, however, it’s not fixed. I’m just hoping to limp through a while longer and if it pack up then I’ll have the vetus unit put in.
Not sure this helps anyone. Si.

 

[VandKoala]

I couldn’t get the port side end cap off, which I needed to do, so as to remove the port side gear shaft, where my oil leak is leaking (slowly) along.
As expected a marine engineer wasn’t prepared to do the work, without removing the gear housing leg from the tunnel entirely. It is tight in there admittedly. This would also mean removal of the drive motor too. He’s costs mounted up quickly and to the point that he said it would probably be more cost effective to replace with a vetus unit.

I’ve had the boat out of the water for a month and monitored the rate of leak and found it to be minimal. More importantly there isn’t any emulsification evident in the oil.

Obviously there is leak I suspect at the shaft seal, but to get at it, I’d need to extract the shaft fully and get it onto a work bench to dismantle properly without causing damage. Of course I’m unable to do this without fear of causing stress to the gear shaft seal to the tunnel.
So, I’m of the opinion that the water pressure is sufficient (now)to prevent the heat box oil from leaking out against the inward water pressure!
Therefore I’ve put it all back together again and relaunched.
Not ideal but I’m mid way through treatment for prostate cancer and……well……let’s see how things go over the next ten months.
It’s still fully operational, however, it’s not fixed. I’m just hoping to limp through a while longer and if it pack up then I’ll have the vetus unit put in.
Not sure this helps anyone. Si.

Hello,

I hope you are well.
My gearbox almost melted down together with the sacrifficial annode in 4 months for my QL BP800. Thinking about Vetus 85kgf.

Have you replaced yours?

Thanks!

 

[shortjohnsilver]

Not yet. I reassembled and relaunched and my limited use of the boat since then - radiotherapy and recovery - has been such that I have not needed it at all.
Keeping a watchful eye on the reservoir where the oil level is stable and continue to hope that the inward pressure of seawater and that of the oil outward is in balance and keeping sea water out of the gear housing. Not ideal by any means but there you go. It’s operational, so should I need to use it I will.
Plan is to revisit things again on haul out next spring and if funds allow replace it with a vetus unit.
Doesn’t help you a lot I know. But I would be grateful to hear if your switch to the vetus 85 kgf is a success?
All the best.

 

[VandKoala]

So the holes are: