OMC Ball Gear

[goinhungry]

I've got a 1980 Chevy 305/OMC I/O that runs like a top, save two issues. First, the ball gears are really worn, and I'm anxious about taking out if they're going to strip on me. All the local mechanics refuse to touch it - they say they either don't have the tools or desire to do it, and they only work on merc/volvos. My question is - is this a job that is horribly complex / are there special tools needed? One mechanic said that on the lower unit you would need to remove the whole drive shaft to change it, but it looks like two nuts and few seals to me - is he right? Should I try to get a mechanic to do it?<br /><br />The other item is that it runs great if I slowly accelerate, but if I punch it, it'll stall out. I think it's prob. a fuel delivery issue (it's a mallory). It will run at WOT if I accelerate slowly, just dies if I peg it... any thoughts? <br /><br />Thanks!

 

[KaGee]

Re: OMC Ball Gear

Changed my ball gears. Did not have any special tools. I needed a new transom seal, so I pulled the drive and the intermediate unit and took them in the house and worked on them over the winter. Pulling the intermediate drive shaft was a piece of cake. The mechanic's comment on the lower unit drive shaft is bogus... he has no clue what he is talking about. Get a manual before attempting anything.<br /><br />I don't know you, or your abilities so can you do it? I don't know. Just to let you know it can be done.

 

[searay3]

Re: OMC Ball Gear

On the fuel issue, sounds like the accelerator pump is not working. Have a partner push the throttle lever open and watch down in the carb (remove flame arrestor). It should squirt fuel in the throat. You can't miss it. If it is not, probably should rebuild the carb. A place to start.

 

[goinhungry]

Re: OMC Ball Gear

Thanks Keith. I suspected that he was FOS - he had a terrible attitude and I could tell that he just didn't want to do it. As far as my background, I'm a self-proclaimed DIY'er - pretty good at figuring stuff out, and I've got a manual for the boat. My dad was an awesome mechanic for 30+ yrs, and I grew up around his shop, but he recently passed away - I was always appreciative of how much he could do/fix things, but that's just one more thing that I really miss about not having him around now! I did inherit all his tools (some of which I have no idea what they're used for - look like medieval torture devices) but for the most part I know my way around a toolbox/garage, just never got into anything too big, which is why I'd be hesitant to do the ball gears if it was more than just draining the fluid, loosening/removing the nuts, pulling & replacing the gears/seals then tightening everything back up. Is this all that's required? <br /><br />Thanks again!

 

[KaGee]

Re: OMC Ball Gear

The biggest issues were:<br /><br />* Use caution in removing the bolts. Take your time and use heat if you run into difficulty. <br /><br />* There are shims behind the bearing caps on the intermediate and the upper drive. If you damage them (most likely will) you have to use a micrometer to guage how thick they are so you can order replacements.<br /><br />*Removing and replacing the ball gears themselves. I placed them in a bench vise. Took a lot of muscle to remove the old ones. Wrapped the new one's in a rag to protect any damage from the vise. Make sure you use the Locktite retaining compound # 609 I believe.

 

[goinhungry]

Re: OMC Ball Gear

Thanks guys. Keith, do you mean "nuts" in your first line, or do I need to unbolt something? In looking at them on the boat, it looks like there's just one nut holding the ball gear in (on both) and I shouldn't need to unbolt/remove anything except those nuts, then the ball gears should pull right out. Am I wrong here, should I be taking out more than this? Is this something I can do while it's on the boat, or do I need to remove sections of the lower unit? If so, I'd rather have a mechanic do it, because once I start getting into bearings, shims, etc., I'd rather pay a little more and get it done right, then try to do it myself, screw up more than was initially wrong with it and then have to give the mechanic more work/headaches (something I saw a lot of at dad's shop...). Thanks again all, you've been a great help. Searay, I'll def. give that a shot - sounds like that might be it!

 

[goinhungry]

Re: OMC Ball Gear

maybe I do need to remove the shaft on the intermediate...?<br /><br /> http://cgi.ebay.com/ebaymotors/New-...ryZ50442QQssPageNameZWDVWQQrdZ1QQcmdZViewItem <br /><br />Do you guys think this is worth pursuing?

 

[KaGee]

Re: OMC Ball Gear

Originally posted by goinhungry:<br /> maybe I do need to remove the shaft on the intermediate...?<br />

YES! You do need to pull the shaft. And yes, I meant BOLTS! There are 4 bolts that hold the bearing cap on both the main drive shaft/ballgear and the upper unit ballgear/gear shaft bearing assembly. You also have trunion cap bolts and trunion cover bolts...<br /><br />

If so, I'd rather have a mechanic do it, because once I start getting into bearings, shims, etc., I'd rather pay a little more and get it done right, then try to do it myself, screw up more than was initially wrong with it and then have to give the mechanic more work/headaches (something I saw a lot of at dad's shop...)

Maybe you should consider that.

 

[goinhungry]

Re: OMC Ball Gear

Thanks Keith.

 

[whywhyzed]

Re: OMC Ball Gear

that ebay link is a really good deal. wow<br /><br />I can't see why pulling the shaft to change ball gears would be req'd though... It looks like a regular old puller would work..no? I'll zing the nut off with an impact to prevent rolling the engine over..or the drive...<br /><br />My only question is about the tin plugs that go in at the end of the ball gear install.. Is there any tricks to popping them in? Any sealant required or recommended?

 

[KaGee]

Re: OMC Ball Gear

Originally posted by hystat:<br /> that ebay link is a really good deal. wow<br /><br />I can't see why pulling the shaft to change ball gears would be req'd though... It looks like a regular old puller would work..no? I'll zing the nut off with an impact to prevent rolling the engine over..or the drive...<br /><br />My only question is about the tin plugs that go in at the end of the ball gear install.. Is there any tricks to popping them in? Any sealant required or recommended?

I was advised, forget by who, not to use an impact wrench. <br /><br />Could you change out the gears without pulling the gear/shafts?? I suppose, your call, but after torching the nut to loosen the retaining compound, what would the seals be like afterward? I wanted to put new seals in while everything was apart anyway.<br /><br />As for the covers, you fill the void with Ultra Black, place the new cover over it. take a flat punch and give the cover a rap with it in the center. The indent flattens the cover slightly, putting pressure around the edge. The pressure and the sillycone hold it there. Let it sit for 24 hours to allow the retaining compund and sillycone to cure.

 

[goinhungry]

Re: OMC Ball Gear

Keith - I think you're definitely right here. My dad always said that it's better to do the job right rather than cut corners and put bandaids on problems. I called around and finally found/met with a good OMC service shop. They're backed up, so I won't be able to use the boat much at all for the rest of the year, but I think it's worth it in the long run. Thanks to all for your help / insight.

 

[goinhungry]

Re: OMC Ball Gear

Keith - I think you're definitely right here. My dad always said that it's better to do the job right rather than cut corners and put bandaids on problems. I called around and finally found/met with a good OMC service shop. They're backed up, so I won't be able to use the boat much at all for the rest of the year, but I think it's worth it in the long run. Thanks to all for your help / insight.

 

[KaGee]

Re: OMC Ball Gear

No problem. I commend you. Sometimes we gotta break down and take it to the pros. <br />