Tranny fluid leakage "86 Martinique BR

Hello all,

Hoping someone can offer advice on my boat issue. I have an '86 Martinique bowrider with the 351 PCM. Understand that it should have the BW 1:1 Velvet drive transmission. The boat is new to me this season. It's got just under 600 hrs on it, and is in really nice original condition (appears to have been well kept & maintained by PO).

I installed a new ACME 540 prop and checked shaft alignment at the beginning of the season. I have run the boat 4 or 5 times so far, including this past weekend and I estimate I've put 5-7 hrs of total use time on it so far this year. I noticed some trans fluid floating in the bilge water the first few times out so I knew I had a tranny leak, but having previously owned an '84 Southwind with the same issue, I wasn't terribly concerned....just knew to keep an eye on the fluid level each time out. The trans was performing ok, possibly a little more noisy/rattly in rev than my prior Southwind, but otherwise ok. The 2nd time out or so, I noticed the trans had difficulty going into forward, but then check the fluid level, which was low, so I topped it off, the fluid level held up reasonably well, and everything went back to normal operation.

This weekend I noticed that the trans fluid leak has gotten much worse. I learned this when the trans slipped after a 20-30 min cruise, even though I had topped off the fluid before heading out.   I had a couple of families with me (and several children who wanted to tube ride), so I kept adding fluid to attempt to limp through the rest of the afternoon. Over the course of the next 2-3 hours and about 1 and a half hrs of actual running time (with several stop and starts changing out kids on the tube), I added about 1/4 quart of a partial bottle of trans fluid, and most of a full second quart to the trans, much of which ended up in the boat bilge making it look blood red under the engine.

The performance and function of the trans is/was as follows: When the trans fluid level is full, the trans still seems to perform ok (?); it engages and pulls both forward and reverse. The trans got hot when the fluid level was low, as I observed smoke/steam from the fill port when removing the dip-stick to add fluid. The trans slipped 3-4 times that I recall, once at about 3K rpms in a tight turn (i.e., additional stress/strain on tranny when turning I suppose), and a couple of times when starting back up under load (forward) from neutral after 20-30 min runs. After the last slip, I noticed a whine in the trans at low rpm that seemed to go away (or get masked by engine noise) at higher rpms (25oo+). From the first time out, the trans has also made a whirring sound if I decelerated quickly from cruising speed, but I read in another post that that was the typical planetary gear (deceleration) sound that it common/characteristic of these BW trannies.

Even though the trans still engages and pulls in both directions when fluid level is normal, I know the trans has gotten hot 3 or 4 times under my ownership. This along with the low rpm whine that started after the last low fluid level slip gives me the feeling that some degree of damage may have occurred (although possibly limited). I obviously have a seal(s) or hoses leaking either on/to/from the tranny or the fluid pump possibly (I understand that these BW's have pumps). I haven't been able to trace the actual leakage point yet, but hope to do so in the next few days.

Other than tracing and IDing the leakage source, does anyone have recommendations for the next steps or things to look for? As far as I know, the tranny is original to the boat and never previously rebuilt. I'm thinking that a rebuild would be a reasonable idea if trans removal is required for seal replacement. I read a post on things to be aware of associated with rebuilds (i.e., thoughtful rebuild of ALL worn components including springs verses simply replacing parts, etc.), and would appreciate any references for good reputable shop(s)/or individuals to work with should a rebuild be needed.

If I can isolate the leak to a hose or other part that can be R&R without trans removal, I'll continue to run the boat with trans as is and see if it will get me through the summer then re-eval at that time.

Thanks in advance for any thoughts/suggestions/shop references that you guys may have.

Jeff in Birmingham, Alabama
1986 Martinique Bowrider, 351 PCM

Yank it out, get it to a reputaible builder and get back to summer without concern you can get back to the dock, because that is what;s next.

Some go to a bottle jack but i Smarly cut two 2x4 wedges to tap under the rear of the exhaust manifolds to support the engine with the rear mounts removed, which minus the trans is basically nuetral balanced because the mounts are in the middle of the engine unlike like the chevy. which has mounts more forward..

Buy a fresh dampner while it a apart, so you only have do this once every 30 years.

Hey, Jeff, how's it going on this project?

I have a '79 Correct Craft Mustang, and I just noticed, after a day of tubing and skiing, that my bilge is full of transmission fluid. It had been leaking since I bought it, which is two years. A mechanic told me that it was a choice between adding fluid once in awhile, and doing a rebuild, so I just added the fluid and kept going.

This, however, is a much larger amount of fluid than I've ever seen before, so I figure that strategy has come to an end and I need to do something serious. Can anybody recommend any videos/manuals/sources to help me on this one?   I'm not afraid of getting grease under my knuckles, but this is the first time I've ever done anything more than add fluid to an inboard transmission.

-boyce

Boyce and Jeff,
I took a look at the link of the Mastercraft rocket scientist. If all you want to do is replace the clutch pac then it's fine but there's NOTHING about pump clearances!!!!! Excessive clearance of the pump is what you both need to be concerned about. It puts oil pressure at the front seal where it's not supposed to. That's where the oil is coming from.

Jeff,
Please report back to what your local shop has to say.

Pete I have to ask because I really don't know. Does the pump wear under normal use? Its just a gear pump riding in oil bath. Under normal use there is an oil barrier, cushion if you will between all the involved parts. Now the OP has a seal issue and has lost oil which can quite certainly damage a pump once that oil barrier is gone. Much like a big or small end bearing. My thoughts are that any damage would be pretty visible to the naked eye. scoring, bluing or what not. What say you? Could metal loss and clearance loss come about without any visual clues? My gear was rough as hell, full of salt water and froze up. I measured every thing in the pump and it was in spec. No signs of wear. I did, I will admit have a front seal leak/ I will also admit it was because I put the pressure relief spring washer on backwards.. OOps! All better now. Just curious what you have seen. I ask because I have seen engine oil pressure increase with new pumps even though anybody with a caliper could find nothing wrong with the old one. Same pump really.
my concerns with this rebuild is the shop not getting the friction plates flat and not stripping (both) pistons for cleaning. The reverse piston can hold a pound of crap and if just jamming forward plates in, will never be cleaned.
We all know the kit is $140. Its the $560 in labor that needs to be properly directed.

John,
Any pump will wear with the hours. You may not see it with a visual inspection. Taking measurements on clearances is the key. The biggest enemy is water. That's the only thing that will produce the visual. Personally, I wouldn't touch a trans. It's just not work risking missing something and have the rebuild go south.