RE: [Cal_Boats] Transmission future woes was - How To Prevent

Thanks Reggie, I have been rebuilding Borg Warner Velvet Drives(BWVD) and other boat gears for many years. I have 4 BWVD s in my shop now awaiting repair. They are well designed, sturdy units, but require maintenance like other mechanical devices. -Check the fluid level before each use. Run the engine to allow the trans fluid to circulate into the oil cooler and immediately check the dipstick after shut off and before the oil drains back into the tranny. It should always be kept at the top dipstick mark. -Change the fluid at least once a year and/or after 1,000 hours. -Always use a top quality Automatic Transmission Fluid, (ATF). Units installed behind a slower turning engine, like your 4-107/8 may use 30wt engine oil according to the BW shop manual. Unless your unit is new or has been recently rebuilt, never change to synthetic ATF. -My experience has been that BWVD s installed in many sailboats die from lack of maintenance, low oil level or water intrusion. -They will wear out. Your engine drives a gear oil pump which engages forward clutches or, for reverse, locks the planetary gear. Seals, bearings, clutch plates etc. all will wear over time. The bearings are oversized and usually do not require replacement. I always replace the input and output shaft seals. I face and turn the output shaft seal coupling on my lathe. I like to face the prop shaft coupling at the same time. Be sure your prop shaft is true. A bent or damaged shaft will quickly damage the output shaft seal, allow the ATF to leak out and you have melt down $$$. -Assure the small breather cap on the top of the BWVD is not plugged with dirt or rust and will allow the fumes from the heated ATF to vent. Failure to keep the vent free will quickly blow the front shaft seal $$$ -Obviously you will always allow the shaft to stop turning before you shift into gear. This may be difficult when you are sailing and wish to motor also. Be careful and shift into forward first to match speed with the windmilling prop. -BW states that a turning prop, as when you are sailing, is permissable for SHORT term only. Putting the trans in gear when the engine is not running will not do anything as it is hydraulic. Boats with folding or feathering props should not have any problem, but fixed props should have a locking device. On Satori, our Cal Cruising 46, we have a Luke feathering prop, 22X22, behind a Walter Vee drive w/ 3-1 Redux, BWVD 71-C and Perkins 4-236. Over 5 knots sailing the 22" pitch will cause the prop to spin. Fortunately, the previous owner of our boat, a fellow named Jack Jensen left us a solution. The BWVD output shaft coupling is easily accessible in our engine room, so Jack used a heavy leather glove to grab the shaft, stop it and attach a pair of vise grips to one of the coupling bolts. The vise grips have a short lanyard attached so, if in an emergency or you forget and shift into gear, they don't launch into space. I have rebuilt a gear on a Cal 39 some years back and it was necessary to pull the engine. I just released everything holding it and slid it forward into the cabin on some boards, then removed the gear. Be happy you have a Borg Warner gear and not the Hurth, ZF or Kanzaki. The latter three are known as the $1.00 an hour gear as they last about 1,200 hours and cost about $1,200. I do not repair these. On the other hand, I rebuilt my BWVD before we left SoCal in 1988. It now has over 3,500 hours and works perfectly. Why? Refer to maintenance suggestions above. I usually charge $375 labor, plus parts for a BWVD brought into my shop in Pensacola. Seals, clutch plates, etc are usually less than $400. Labor rates vary, check locally. YMMV Tom