B/W tranny leak

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Dixie Life

Senior Member
Joined
Feb 4, 2011
Messages
213
Location
USA
Vessel Name
Aku Uka
Vessel Make
43’ DeFever
I had a leak at the rear seal, had a shop replace the seal.* No leaks for a short time, then leak started again.* The orig. leak was*by the*seal and flang coupler shaft.**The new leak isn't*there; I had a hard time finding where it was comming from.* Finally found it was leaking at the inside of the flang shaft where the nut is, flowing thru the inside of the flang shaft and prop/coupler shaft, then out of the Federal flexable coupling.* My question, is there a seal or something behind the nut? How can it be leaking around the nut?* I'm waiting for some*advice before I try taking the nut off or going any*deeper into it.*
 
Is there a vent on the tranny?* If so is it blocked?* Sounds like it is getting past the seal.
 
Assuming your talking about a BW 71 or 72 series,yes there is a seal there and when you assemble the flange you are supposed to use gasket sealer on the splines so it doesn't leak thru them as it sounds yours is. Doesn't say that in the manual, but an oldtimer who rebuilt hundreds of them told me that tip.

I have the manual in PDF, if you want it send me an e mail to me at the address below.

jleonard@usa.norgren.com
 
Also note that the nut is torqued to I believe 250 ft lbs.* Often times shops just use an impact and don't check the torque.* It makes a difference in preventing leaks from the rear seal.........................Arctic Traveller
 
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