Tranny slipping again???

[jleger98]

Hey guys,
Monday night we were out surfing and we had the crap weighted out of the boat. Water above the rub-rail sorta thing

The tranny seemed to be slipping, but I again ignored it because I figured it was cavitation on takeoff. Then when we took it around the lake to "burn off a little carbon" it slipped on takeoff. I had this issue a little last year, right after I bought it, but that proved to be bad fluid. Changed the fluid and it was fine.

I checked the fluid in the driveway that night and the color was nice and red. Obviously I need to check the level on the lake, so it might be that the level is just a little low.

At one point, the gal driving shut off the bilge pump....not sure why. Anyway, after about an hour, my daughter noticed water running out of the bilge onto the floor when we were pulling someone. Question is, could having too much water in the bilge cause the tranny to slip?? Again, the fluid did not look frothy, and looked like fluid that only had about 15 hours on it....which it does.

We're going out again Friday night, so I'll get out a little early and see if I can replicate it, and check the level. But any experience with bilge water causing the tranny to slip? There appear to be no leaks.

[scoot18]

Is it even possible for the tranny to slip?

I thought they were direct drive, gear to gear.

To my knowledge there is no clutch pack in the trans that could slip.

It is a gear to gear mesh. The only way it could slip is if there were teeth broke off one of the gears.

Sounds funny to me. Unless there is some type of saftey disengage built into the trans to minimize damage in the event something gets locked up on the prop shaft.

Very good question, I will be interested to see what the others here say about it.

[dogbert]

Are you sure it wasn't belt slippage this time? With that much water in the boat, it could be that your belt was slipping due to all the water being sprayed all over your engine compartment.

Cavitation is definitely a possibility. You may have to get a lower pitched prop to compensate. I run an 13x11 3 blade. I think it's an Acme 825. It definitely helped with the cavitation issue.

[21V_Swe]

Is it even possible for the tranny to slip?
I thought they were direct drive, gear to gear.

Scott, the tranny in theese boats are hydraulic, not mechanical, thats why the gear engages so smoothly compared to a I/O. Works just like a automatic tranny on a car except that its only Forward and Reverse, no more gears. What happens is the outgoing shaft of the engine connects to a oilpump in the tranny. When you choose to go forward the oil is routed so that discs are compressed and connects the the shaft from the engine to the outgoing shaft. The tranny got to have at least 8 Bars of pressure, 9.5 is good, otherwise it will slip. The higher the load, the easier the slip.


jLeger,
One of the following could be your problem:
1. Too much oil (had this problem on my old MC)
2. Not enough oil
3. Wornout discs.
4. Piston and piston rings in oilpump wornout.

Start with the oil, thats the problem 99 times of 100. If that doesnt help I would recommend an authorized Borg Wagner mechanic. Or if you, like me, like to fix things yourself,order a rebuild-kit and do it.(I think it's somewhere close to 500$)

[jleger98]

I did the first, and wow, it was low, took almost 1/2 a quart. Where the heck could all that fluid have gone??? No leaks in the bilge.....No smoke or oil slick or anything......Either way, added some fluid and it fixed it right away. Whew. Was hoping I wasn't going to have to rebuild it.

Swe, I am usually a DIY guy, is that rebuild hard to do?? $500 has got to be a heck of a lot cheaper than getting someone else to do it.

[21V_Swe]

If you know what you're doing, rebuilding the tranny ain't that difficult, it just take some time.

[dogbert]

Thanks for the update...I guess it's a good idea to check fluid levels every so often. Too bad it's so hard to get to.

[jleger98]

Mine isn't bad as long as you don't have a bag sitting behind the engine cover. Then it becomes a pain in the arse.