OMC outdrive starts climbing when in reverse

[bosshoff]

My 1970 OMC 225 outdrive climbs when in reverse. Is this some sort of "Clutch Pack" problem? How do I fix this? Where can I get parts for this? Thanks. I searched reverse problems, but wasn't able to narrow down my results.

 

[Howard Sterndrive]

Re: OMC outdrive starts climbing when in reverse

there is a clutch pack in there. yours is slipping or broken. parts are available at any evinrude dealer. shop.evinrude.com has exploded views with part numbers, prices and availability.

 

[NW Redneck]

Re: OMC outdrive starts climbing when in reverse

Howard's right. Does the drive go up and down with the switch? Can you lift it up by hand? Once up, does it stay up or does it come back down? (Quickly or slowly?) It could be a broken part or a snap ring has come off, or it could just need to be pulled apart and rebuilt. Gimme a little more info and I can probably help you out.

 

[superbenk]

Re: OMC outdrive starts climbing when in reverse

Sounds like the clutch pack is wearing out or the retainer ring broke as stated. You can pull the clutch pack apart clean it & repack it (you'll need a press) which might help if the plates are still good.

Also, check the ring gear around the clutches & the worm gear on the shaft. Make sure the worm gear is still there & there aren't any damaged teeth.

 

[bosshoff]

Re: OMC outdrive starts climbing when in reverse

I have read your replies. Thank you everyone for your help so far. I looked for a schematic showing the Tilt Motor, and don't see any "clutch pack"? On the port side of my engine I have a 6.0" round oil filled reservoir which I drain and fill each year. Is the clutch pack located inside this unit? someone mentioned a "press" to service this part. I do not have a press. Should I leave this up to my mechanic, or is this something a shade tree guy can accomplish? I'm good with mechanical things, just light on my boat engine knowledge. To give you more details on the symptoms, the boat goes up and down fairly well. Some times it clicks and does not motor up or down, which I attribute to the posibillity of corroded terminals/wiring. I will address this next. When I back up, off the shore station, the lower unit is no longer flush against the transome. It has probably climbed 10 degrees. Before I go forward, I again will push the lift button down, and the motor thunks down into place. Anythime I use reverse, it will come up.
Thanks.

 

[superbenk]

Re: OMC outdrive starts climbing when in reverse

There's a series of clutch discs inside that 6" housing on a shaft. That's the clutch pack. It's held together by a snap-ring and some spring washers (they're dish-shaped). In order to get it apart or together, you need to compress those spring washers to release the pressure on the snap-rings. That's what you need a press for. You can also do it with a vice (I did). It's not hard to do, just keep track of the order things were in when you take it apart. If you search here, you'll find a number of posts about how to take the clutch pack apart, clean it, re-oil it and put it back together. I suspect that since you're only getting 10? of movement that just rebuilding the clutch pack will fix your problem.

 

[NW Redneck]

Re: OMC outdrive starts climbing when in reverse

Good advice from superbenk. I rebuilt mine without a press a well. A vice and a couple of pieces of the right diameter pipe will work just fine. Go over ALL the wiring connections in the tilt system starting at the battery, the connections at the switch, the solenoids, and the motor leads. Any loose, dirty or poor connections will give you problems. Make sure your battery is in good shape and fully charged as well. If the solenoids are originals I would replace them as the contacts inside may be weak/corroded. They are <$20 each and readily available. If the tilt motor has never been out (or not for many years) I would pull it and have a look inside. If water has sat in the bilge for any length of time it WILL get into the motor and corrode it internally. The motors are not hard to rebuild if you are mechanically inclined, and if not most motor shops can do it fairly cheap. The biggest pain in the @** is re-installing the motor when you're done. Being double jointed and having eyes on the end of your fingers helps.

 

[bosshoff]

Re: OMC outdrive starts climbing when in reverse

OK, I got my clutch pack removed, disassembled, cleaned, and reassembled. I also have a second unit parted out from a junk drive. My comment is this, it was not hard to disassemble or reassemble the units? I did NOT need a press or a vice? Once assembled, the one of the unit turns pretty easily, the other requires a bit more force. My old CP had three dished washers (spring washers?), while theCP from the parts drive had only two. The CP from the parts drive also had a thick washer, which my old CP did not have? Does anyoe have an exploded diagram which shows exactly how this unit is supossed to be assembled? How much force should it require to spin the clutch disks? Should it be easy, or hard? Thanks.

 

[Howard Sterndrive]

Re: OMC outdrive starts climbing when in reverse

it should take about 300 foot-pounds of force to spin the discs - something's not right there - probably best to just install the other CP and call it a day
shop.evinrude.com has all exploded parts views, part numbers, prices and availability online back to 1968

 

[NW Redneck]

Re: OMC outdrive starts climbing when in reverse

Sounds like neither one was assembled correctly. If you did not need a press or vice to compress the springs, then something is missing. Starting from the end of the clutch shaft that goes into the housing cover, there should be:

1 retaining ring (snap ring) smaller
1 spacer (washer)
3 belleville springs
clutch plate
clutch disk
plate
disk
plate
disk
plate
disk
end plate
? shims (pic not good enough to see how many shims. Looks like 2 or 3)
1 retaining ring - larger

When installed, it should take 130-160 ft/lbs of torque to slip the clutch.

 

[bosshoff]

Re: OMC outdrive starts climbing when in reverse

OK. Both units were not installed correctly. I have since fabricated the "tool" to press everything together and install the snap ring. I will assemble the unit correctly. I have a question about the shims. Do I check the ft/lbs. of torque that it takes to slip the clutch, and if it is lower than 130-160, then I need to add shims? I have two small shims. One is skinnier than the other. They both are very small. I am going to assemble the unit without the shims, and see at what ft/lbs. it slips. Thanks.

 

[Howard Sterndrive]

Re: OMC outdrive starts climbing when in reverse

most people just sort of stand on the drive.... if it holds their weight with a bounce, it's good. If you can figure out how to get a torque wrench on there, you could do that - seems like it would take a lot of fabrication though
I've never worried about it being too tight.... and have only adjusted it on the later 1980's clutches that had a friction adjustment screw in the center that could be adjusted on the boat
Lots of people have pinned/welded/bolted them solid.... to give the same amount of shock protection as every Mercruiser drive (i.e. none)

 

[NW Redneck]

Re: OMC outdrive starts climbing when in reverse

The shims are what set the 'load' on the clutch pack. Adding shims increases the torque required to slip the clutch. The diagram I have looks like there are 3 shims. If you have 2, I would put both in. There is a special tool (of course ) that is used with a torque wrench to test the torque, but Howards idea of just standing on the drive works just fine. (That's what I did. )