BW 2.6:1 Reduction - reliability? Spares?

My Willard 36 with Perkins 4.236 has a BW 2.61:1 reduction gear. It probably has around 2000 hrs on it. I'm set for my engine and a decent shade-tree mechanic, but I confess, I've not really worried about the tranny except to change oil every couple years. How reliable are these? Any spares I should consider for semi-remote cruising (Central America)?

Any informed opinions on these transmissions?

Thanks in advance -

Peter

They will run as long as almost any engine. The flex plate may begin to rattle at around 5,000 hours or less. It is an easy, pretty cheap fix.

pete

Do you know what model the trans is? I don't know of a 2.61 ratio Velvet Drive, so I'm wondering if it's a something else.

If it's a Velvet Drive, I've got a pair of 2.57:1 reduction 72C transmissions in my boat. I sheared the teeth off the stationary plate in the reduction gear around with around 1550 hours on the port trans. No collateral damage, just had a new plate overnighted, pulled the reduction housing, swapped it and it's been fine since. No symptoms leading up to the failure either, it just went from fine to no power output very suddenly while cruising.

My stbd trans suffered the same failure about a year prior (before it was in my care) at around 1500 hours. However, the stbd one had some noise and symptoms leading up to the failure, as well as some visible gear damage, so it got a full rebuild.


Other than that 1 weak point, they've been rock solid. At this point, I've got about 1700 hours on the port trans, about 180 on the stbd rebuild. Keep in mind, my transmissions are behind a pair of 340hp engines that turn ~4200 RPM at WOT (fast cruise is 3300 - 3400).

Only thing to watch is not setting the idle too low (causes damper plate rattle). You're putting far less power and RPM through your transmission than I do, so it'll likely hold up just fine. Do keep an ear out for damper plate rattle though, as lower RPM and/or rougher idling engines tend to be harder on damper plates.

Sounds like a damper plate is not a bad spare to keep around? I confess, I'm 100% ignorant about transmissions. For some reason, I want to say it's a model 72 Velvet Drive, but I don't know why I say this.

I found a reference in TF archives from fellow W36 owner Brooksie in 2012 - any feedback on this PYI product?:

Keep in mind, replacing a damper plate typically requires pulling the trans off the engine. So it's not necessarily an at-sea repair.

rslifkin said:

Keep in mind, replacing a damper plate typically requires pulling the trans off the engine. So it's not necessarily an at-sea repair.

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Yea, I understand the general process of sliding the shaft/coupling back and removing the gear. The pressure plate is flat and relatively small so fairly easy to store. The R&D pressure plates seem to get good reviews. I may have it replaced as I have a decent mechanic in Mexico. Plus, looks like there are several measurements to confirm prior to ordering a replacement - easier to do now where the boat is sitting anyway.

I had the engine out of the boat a few months ago. I wish I had thought to do it then. Looks like aligning the transmission back in-place can be a PITA.

Peter

Pete Meisinger said:

They will run as long as almost any engine. The flex plate may begin to rattle at around 5,000 hours or less. It is an easy, pretty cheap fix.

pete

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Not good advice in MY opinion.
The first summer that I had my Albin, I decided to pull the BW 71 series and do a rebuild. It was running fine not any indication of trouble. The engine had 3400 hours on it.
When I pulled it apart the paper clutch surfaces were almost totally gone and pieces were floating around inside.
The reverse cylinder was starting to rust on the top and I'm sure that if eft for another season it would have destroyed the tranny.
These trannys are simple and pretty easy to rebuild yourself.

And the damper was fine, but since the tranny was out it was a no brainer to replace it.

Replaced my dsmpner on a 135 Lehman in 2.5 hours. Go to our blog, grandbankschoices to see how we did it.

You would have to have no other option and all the parts to do it at sea.

Choices said:

Replaced my dsmpner on a 135 Lehman in 2.5 hours. Go to our blog, grandbankschoices to see how we did it.

You would have to have no other option and all the parts to do it at sea.

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Thanks - good blog. I tried googling to find the right blog entry and found this TF thread on replacing a damper plate, which was helpful.

Thanks so much everyone - I learned something today!

Peter

Damper plates like most boat parts can be had in various quality levels.


Buy a good one or just carry 2 on board,for remote operation.