Drive slipping....help

[Phantom17]

Hi all, I posted about my drive slipping in low rpm but it now does it at all rpm except idle. Feels like a clutch slipping. Tried both props and a fluid change of the upper, lower and intermediate housings. Any suggestions on what to do? I'll tackle anything, but not sure where to start. 1981 OMC 2.5 GM litre, 400 OD. Thanks.-Jeff

 

[Laddies]

Re: Drive slipping....help

jh, ck the drive coupler on the back of the engine

 

[Phantom17]

Re: Drive slipping....help

Thanks for the relpy. How do I do this properly? I am guessing I have to remove the outdrive to solve this problem. If your talking about the gear set meets at the back of the int housing, the engine side is slightly worn, the O/D side is less worn. I have a manual, but of course it doesn't cover the troubleshooting you need. Appreciate your reply, I am mechanically inclined, just not sure where to start or exactly what to look for. -Jeff

 

[KaGee]

Re: Drive slipping....help

Remove the drive, drain the oil from the intermediate unit, pull the bearing carrier/ball gear/drive shaft assy. Inspect the splined shaft for excessive wear or metal particles. You should be able to shine a light inwards to see the coupler. This will only give you a rough idea if that may be the problem.

 

[Phantom17]

Re: Drive slipping....help

Keith, what about the clutch dog and assy in the lower unit? I ask because it feels like a transmission that is low on fluid, or a slipping clutch. Just a thought. Looking at the the manual, I would think if it was the clutch pin in the lower unit, it would sheer right off and not work at all. Well, so much for changing all those fluids..... BTW, reverse works fine. I'll try to pull the O/D off tomorrow or tuesday. Keep me posted if you come up with anything else Keith, and as usual, thanks. -Jeff

 

[Don S]

Re: Drive slipping....help

Clutch dogs don't slip, they jump out of gear and bang back in. <br />The OMC out drives are a million miles from how an automatic transmission works.

 

[KaGee]

Re: Drive slipping....help

Drain the lower and inspect the fluid for excessive shavings.

 

[Phantom17]

Re: Drive slipping....help

I just changed lower, upper and int fluid. Little milky in the upper, not horrible, but enough. Lower was a little on the low side, but not discolored, int housing was not discolored either. No hard shavings in lower fluid. <br /><br />Thanks Don, I know they're not even close, it just felt the same as when an auto trans is low on fluid, hence the reason I changed the fluid. <br /><br />This was the first symptom, only happened at lower rpm. Now at all rpm except idle, which is what I did to get back in.....

 

[Boomyal]

Re: Drive slipping....help

Jh, it ain't your coupler. Your '81 has the late large splined coupler and shaft. They don't wear and spin like the pre '79's could. I wish I could give you a better idea but once you get inside the OD's my knowledge is limited. <br /><br />You sure your prop hubs are not slipping? Not likely to be two of them but if they are not then you have a problem inside the OD.

 

[Phantom17]

Re: Drive slipping....help

Hey Boomer, whats new? The secoond prop is in excellent shape, except the small nick I did on the maiden voyage.....(duh). I've been using the back up one (in decent shape) since then (april). Only difference in boat usage was an hour and half at different speeds, and probably 35 minutes of pulling my 11 yo around on a tube at 3000-3800 rpm without a problem. Next time out the problem started only at lower rpm. Changed lube, and the problem is at all rpm now. Theres some stuff in that O/D I don't want to get into. Just wish I had an idea what to look for, a starting point.

 

[DHPMARINE]

Re: Drive slipping....help

Could you have an older drive than 1981 ?<br /><br />sounds like an older electric shift problem.<br /><br />DHP

 

[Phantom17]

Re: Drive slipping....help

How do I tell? The only wire visable (with drive on) is the ground wire to the upper housing. I'd really like to tackle this myself if possible. Boat money is VERY lean.

 

[Phantom17]

Re: Drive slipping....help

Should I be able to spin prop in gear by hand? I can spin it in forward, and I can hear the exhaust blowing air out. It is easier at parts of the rotation, and more difficult at others. Indication of???????

 

[Boomyal]

Re: Drive slipping....help

Originally posted by DHPMARINE:<br /> Could you have an older drive than 1981 ?<br /><br />sounds like an older electric shift problem.<br /><br />DHP

Electric shift does not have thru the prop exhaust. Both the hydro-mech (77-79) and mech (80-86,7?) 800 stringers have thru the prop exhaust and share the same upper gearcase.

 

[Phantom17]

Re: Drive slipping....help

I have throught the prop exhaust. My guess is it's original. Boomer, what of the "prop spin by hand in gear" thing? Motor is obviously off......

 

[Boomyal]

Re: Drive slipping....help

My guess is that, in nuetral it should spin freely in any part of the rotation. Of course, in gear, nada.

 

[Phantom17]

Re: Drive slipping....help

Spins in forward by hand through to the fan belt. I am barehandedly turning the prop. It turns hard, then easier, the hard again, then easier again......Still think coupler? Even if the fan belt is turning?