ball gear info

breakingbass

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in a previous thread, i have been posting in an attempt to figure out why i lost drive to my propeller shaft on my OMC stern stringer. i have the lower housing off and i will be dissecting it to see if i have a break in it. when i push on the shift rod and turn the prop shaft by hand i can see the spindle on the other end turning. does that mean that the lower housing is in good shape?

i suspect that the break is in the intermediate housing. my question concerning the ball gears is whether the ball gear coming out of the stern (the ball gear mated to the coupler) should be turning when the motor is running and in neutral. this would tell me a lot in terms of whether my break is with the coupler or in the intermediate. thanks in advance.
 

southkogs

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Ball gear(s) should always be turnin' when the engine is runnin'. Your upper gear case should turn by hand when taken off the sterndrive (might be a little tough without a tool, but should turn without you gruntin' too much).
 

breakingbass

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thanks for the reply. we got the lower off and we will be rebuilding it with new seals and all that good stuff once i get the seal kit in. as for the upper, we will also be taking that apart to inspect and rebuild as well. so the ball gear coming out of the stern should always be turning even when the engine is in N and idling? thanks for the insight, it is really much appreciated. i will report back with my latest findings at the end of the weekend.
 

southkogs

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... so the ball gear coming out of the stern should always be turning even when the engine is in N and idling?
Correct. And consequently that means the ball gear and entire upper gear case of the sterndrive are gonna' be movin' too while in N. Shifting all happens in the lower unit.
 

breakingbass

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so it would be safe to say that if the ball gear coming from the stern is not turning when the motor is on, that this owuld be a sign of a broken ball gear shaft or coupler? my buddies are coming over tomorrow to help me further diagnose where our break happened. thanks again, the knowledge is very much appreciated.
 

southkogs

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Correct. That ball gear not turning on the stern would indicate a problem in that shaft somewhere.
 

breakingbass

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thanks south, this evening we were able to remove the intermediate housing from the boat and confirmed that the failure is in the intermediate housing. we turned the ball gear by hand on the intermediate housing and the shaft on the other end doesnt spin. not only does it not spin, but we can hear some definite rattling when we turn it.

we ran out of daylight so we didnt get a chance to remove the shaft from the housing to expose the break. i will post again when we make more progress. thanks again for all of the info.
 

southkogs

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Let me correct myself for clarity: ball gear on the engine side should NOT move by hand. It should always be going when the engine is running. Ball gear on the upper gear case (stern drive) side should turn by hand (when the upper is off the lower) and will always be turning when the engine is running.

Good luck working through it. Mine overheated this weekend, so I'll be in the garage with ya' this week ;)
 

Howard Sterndrive

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I don't get all the seal kits? Is there water in the gear oil?

Most probable cause of loss of propulsion is stripped splines on the upper end water pump shaft that connects the upper and lower gearboxes. But I can't follow what's turning, not turning etc. here.

I think the OP is calling the upper gear box the intermediate and that is making this thread a mess.

A few minutes of looking at diagrams in the factory manual can save hours of unnecessary work tearing into things that are fine, and you'll be fairly sure you're calling the parts by the right name.

Pressure test upper and lower and if they pass, don't mess with the seals. If the kits are aftermarket you'll be taking out good seals and putting in cheap ones.
 
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breakingbass

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i have the seloc service manual and the exploded diagram refers to the upper part of the out drive as the "intermediate gear housing". the seal kits i found online are kits that contain gaskets i need since pulling the drive apart.i wont need to replace every seal, just the ones that need replacing, unfortunately i have had a hard time trying to find the individual gaskets and seals for sale online. i especially need the gasket for the shift housing, and the ring that goes between the upper and lower housings, mine are thrashed.
 

southkogs

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You're a mechanical shift which is a little different than mine, and I don't know it as well. Listen to Howard - He REALLY knows these systems. Many parts are still available from Evinrude.

The intermediate housing (ball gear coming from the engine) passes through the transom boot:


The Upper Gear Case (ball gear coming from the stern drive) is the upper portion of the stern drive:
 

breakingbass

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im sure howard sterndrive is correct, im pretty new to boating and am just learning the ropes. im just explaining why i was referring to it as the intermediate. the entire chapter in the service manual i have refers to it as the intermediate. as soon as i get that shaft out, ill post pics and report back.
 

breakingbass

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UPDATE: i took apart the upper gear housing and found that the shaft that the water pump and impeller live on. here is what it looks like.









when we tried turning the gear the shaft on the other end does not spin. this leads me to believe that this is where our break is. i was thinking about taking this piece to a boat mechanic and seeing if they can replace the shaft with a fresh one and put this assembly back together for me. i called a mechanic in town and he said they dont usually work on parts, but they would be willing to if we could wait a week because they were so backed up.

after reading the service manual and looking at videos online, it seems that i would need a press and a special tool to perform the fix myself. does anyone have differing opinions on this? any help, opinions, thoughts or info will be really appreciated.
 

Howard Sterndrive

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I'm not sure what we're supposed to be observing in your pics. Everything looks ok there (no?).
In your 3rd pic, see that shaft with the female splines on it...
Remove that shaft with the water pump impeller and look at the OTHER splined end. That is the one that likes to strip out due to poor maintenance. (impeller should be changed every 3 years and the splines are greased then)
You are 95% of the way in... just need to finish disassembly.
 

breakingbass

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what i was asking in the previous post was whether it was possible to take the assembly in the pictures apart in a home garage, or whether this is something i needed to take to a boat mechanic to get apart b/c i thought it may need some sort of press that i dont have in my garage, or shop at work.

after showing it to a mechanic in martinez, he gave us some good advice on how to safely take the thing apart, and we were able to separate the two shafts that hold everything together. the lower shaft came off and the impeller and housing came with it. the impeller looks preety new and that it had recently been replaced. sure enough, the splines on both shafts were stripped, and both shafts will need to be replaced. we were able to to get the nut off of the upper shaft next to the pinion gear, but we are still unsure how to remove the pinion gear and the bearings from the upper shaft so that we can replace it.

im hoping someone out there has some tips or advice on how to get the pinion and bearings off of the broken upper shaft so that we can finally replace these busted shafts, and get this stern drive back in working order. thanks again.
 

Howard Sterndrive

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im hoping someone out there has some tips or advice on how to get the pinion and bearings off of the broken upper shaft so that we can finally replace these busted shafts, and get this stern drive back in working order. thanks again.

basically, follow the steps exactly in the factory service manual. Where you will find out you need a bunch of specialized tooling which makes it a job for a shop already equipped. You can sometimes get all the tools on ebay for a few hundred and then resell them. Not usually though.
 

breakingbass

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UPDATE: i found a place online that sells OMC parts. they put me in touch with their mechanic and he gave me some good advice on how to take apart the water pump, bearings and pinion from the shaft i need to replace. i found the specialized tools the service manual calls for on the same website and they cost about 120 bucks. it looked just like a basic bearing puller and i found the exact same thing at harbor freight with the same dimensions for 35 bucks. it worked like a charm and i was able to separate the pinion and bearing from the shaft. there are two shafts that need to be replaced, and i just ordered them, including a new seal kit with all of the gaskets i will need to put it back together. in total, it cost me about 300 bucks for everything. the mechanic also recommended that i use 80-90W gear oil for johnson or evinrude outdrives, and marine loctite for all of the fasteners.

another problem i ran into was that 4 of the 5 bolts holding the shift mechanism housing to the lower drive were galled to the lower housing and snapped while we were taking the out drive apart. we solved this by using an angle grinder to flush the bolts to the housing. then we built a stand out of a series of 2 x 4''s which would hold the lower drive level and stable at 180 degrees. we then put the lower drive and stand in my drill press and blew out the bolts that were galled. we then retapped the holes to M6 (they were previously 7/6") and bored the housing holes to match.

so now all we are waiting for are the replacement parts to come in and then we will start piecing it all together. i still havent removed the pump shaft completely off of the pump housing and there is still one set of bearings inside as well, but i am going to tackle that this afternoon. we also decided that we are going to do an oil change, replace plugs and wires and tune the carb while we're at it. ill post again with results.
 
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