| Author |
Message |
    
graham
Member
Username: holinwtr
Post Number: 61
Registered: 10-2006
| | Posted on Sunday, May 04, 2008 - 08:58 pm: | 
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I recently changed the fluid in my out drive. I have a 165 L6 by the way. I ran the engine on the muffs in the driveway and noticed the front engine mounts were rotted. So I pulled the motor and the outdrive. When I drained the fluid from the outdrive it had water in it. Where would water be getting into the fluid by only running it on the muffs for about 10 min? |
Bt Doctur
Advanced Member
Username: bt_doctur
Post Number: 261
Registered: 06-2006
| | Posted on Sunday, May 04, 2008 - 09:52 pm: |
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shift shaft seal. lower water pump base seals |
graham
Member
Username: holinwtr
Post Number: 62
Registered: 10-2006
| | Posted on Monday, May 05, 2008 - 08:55 pm: |
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Thanks Bt Doctur. While i've got the outdrive on the stand i'll pull the upper unit and replace the water pump seals. Is the shift shaft seal you're refering too where the upper and lower units meet? |
graham
Member
Username: holinwtr
Post Number: 63
Registered: 10-2006
| | Posted on Monday, May 05, 2008 - 09:04 pm: |
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One more question. I got the gasket set that comes with the main gasket that joins the outdrive to the bell housing. There is one big oring that goes in the u joint bellows. The medium size one goes on the water inlet hole but where do the two smaller orings go? |
bill davis
Member
Username: milford65
Post Number: 31
Registered: 01-2008
| | Posted on Monday, May 05, 2008 - 10:33 pm: |
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drive shaft should have 2 o rings on it where the gimble rides on it |
Bt Doctur
Advanced Member
Username: bt_doctur
Post Number: 269
Registered: 06-2006
| | Posted on Tuesday, May 06, 2008 - 12:30 am: |
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The one for the bellows is GLUED IN PLACE ,dislodged during installation you will leak. |
David R Cole
Member
Username: david_ray
Post Number: 67
Registered: 02-2008
| | Posted on Tuesday, May 06, 2008 - 12:32 am: |
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The two small (about 1" diam) o-rings do not seem to be used on the Alpha drive, perhaps for an earlier design. If stretched to the size of the drive shaft (if they don't break first) the thickness would be drawn down to a size they would be buried in the o-ring grooves and not serve as a seal. Those two o-rings in my package went into a misc bin on the spare parts shelf. |
Bt Doctur
Advanced Member
Username: bt_doctur
Post Number: 270
Registered: 06-2006
| | Posted on Tuesday, May 06, 2008 - 12:40 am: |
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nope, they go on the input shaft .they ride inside the gimbal bearing inner part. |
graham
Member
Username: holinwtr
Post Number: 64
Registered: 10-2006
| | Posted on Tuesday, May 06, 2008 - 05:16 pm: |
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Thanks to all. So the two smaller o rings go inside of the gimbal bearing. Is the shift shaft seal that I should look at where the upper and lower units join? |
Rod Stewart
Senior Member
Username: rod_stewart
Post Number: 1248
Registered: 08-2006
| | Posted on Tuesday, May 06, 2008 - 07:58 pm: |
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graham;
The oil passage between the two halves is sealed by a tiny "quad" type o ring seal. Its about 3/8" diameter. It has a square cross section so its called a quad seal.
The lower shift shaft is right at the front of the lower unit. It sticks upwards and has a 90 degree hook at the top of it. It has nothing to do with holding the two halves of the drive together. It turns about 90 degrees to shift the lower unit from rev to neutral to fwd. The seal on this shaft may be leaking.
If you change this seal, its accessible by undoing the two small bolts that hold the white plastic fitting in place. Note that you should put the lower unit in a vise straight upright, and put the shift shaft in the straight ahead position before removal. Then carefully insert the shaft in the same forward position on reassembly. The shaft splines into the shift arm in the lower unit and you can easily get it in the wrong position. If this happens you wont be able to shift any gears at all.
When done, check the gear shifting and make sure it is working correctly.
Rod |
graham
Member
Username: holinwtr
Post Number: 65
Registered: 10-2006
| | Posted on Tuesday, May 06, 2008 - 09:05 pm: |
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Ok, I've taken the two halves apart (for the first time) and I'm starting to see how things are working. My main goal here is to find out how water got into the oil by only running it on the muffs. It was never dunked. So with that in mind, I don't see how the shift shaft seal could leak water into the fluid unless it was dunked. Am I wrong in thinking that it could be exhaust water getting into the tiny hole where the two halves join? It could also be intake water pump seals like Bt Doctur said. Is there an o ring on the 3/8 oil passage hole? If there is, and that has failed then that's where I would think water could be getting in? Also, there was no gasket betwix the two halves, is that supposed to be like that or did someone forget to put one in?
Rod, I did not see the two small bolts that hold the white plastic fitting for the shift shaft seal. I saw the shift shaft and how it works when I got everything apart. I also saw that it does have to put back together with the shift shaft facing forward to line up the teeth. Are the two bolts you speak of on the upper or lower unit?
I also took the water pump off which was a good thing because the impeller needed to be replaced. But I couldn't get the hard plate and the last gasket off because of the ridge that holds the impeller in place on the shaft.
Any more advice would be greatly appreciated. Thanks to all |
Guy Gaspar
Senior Member
Username: guyjg
Post Number: 1982
Registered: 08-2006
| | Posted on Tuesday, May 06, 2008 - 09:51 pm: |
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No gasket between halves. The impeller is held in place w/a keyed shaft. Just pull or pry it straight up and off. |
graham
Member
Username: holinwtr
Post Number: 66
Registered: 10-2006
| | Posted on Tuesday, May 06, 2008 - 10:02 pm: |
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Thanks Guy. I did get the impeller off, I just couldn't get the hard plate and the last gasket off. The real question is , how do I get the new hard plate on without destroying it. I can get the old one off if I have too. |
Rod Stewart
Senior Member
Username: rod_stewart
Post Number: 1249
Registered: 08-2006
| | Posted on Wednesday, May 07, 2008 - 12:13 am: |
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graham;
As I said in my earlier post, "The oil passage between the two halves is sealed by a tiny "quad" type o ring seal. Its about 3/8" diameter. It has a square cross section so its called a quad seal."
That is the only gasket between the two drive halves, as there is no need to seal anything else.
The two bolts for the shift shaft retainer are on the lower half. Send me an email offline and I'll send you a picture illustrating what it looks like.
The stainless pump baseplate should come off fairly easily. You should replace it with the new one in your pump kit if it is scored or scratched at all. Scoring happens when the water pump picks up sand and other debris in shallow water.
About the only way you are going to find out what is leaking is by a pressure test. You could pressure test the lower unit easily enough by using a compressed air jet with a small tapered end that will fit into the oil passage in the lower gear case. Apply pressure and see if it leaks anywhere. If in doubt partly immerse it in water and look for bubbles (not the one in Trailer Park Boys).
Set the air pressure regulator down to 10 psig or so. You don't need more than that. The only way to pressure test the upper case is with the drive leg reassembled. Then you test the whole thing through the vent hole.
Rod |
Rick Root
Member
Username: rickroot
Post Number: 16
Registered: 05-2008
| | Posted on Wednesday, May 07, 2008 - 08:32 am: |
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I'm no expert, but water flowing into the stern drive through the muffs goes into the water pump but near as I can flow into the cavities of the lower unit in front of and behind the water pump housing. So, water could in theory get into the oil amongst the gears in one of FOUR ways.
#1 - through the oil passageway between the upper and lower units. I'm told that gasket should be replaced EVERY time you take apart the lower unit. If you don't have one that's a problem. If you have one, replace it.
#2 - if the o-ring in the water pump base housing is damaged, water could get into the oil that way.
#3 - the o-ring near the top of the drive shaft, and maybe the upper drive shaft seals (in the upper unit) could allow water into the oil that way.
#4 - the shift shaft seal in the lower unit (below the stainless steel washer).
If I've said anything terribly wrong here, someone please correct me so I can learn too  |
Guy Gaspar
Senior Member
Username: guyjg
Post Number: 1984
Registered: 08-2006
| | Posted on Wednesday, May 07, 2008 - 09:41 am: |
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graham:
Rod said:
"The stainless pump baseplate should come off fairly easily." He is more knowledgeable and experienced (seriously) and much older than I am. 
The previous person may have used a gasket glue on the plate, etc. or the lower half of the WP hsg. got hot enough to distort the plastic hsg. like mine did. The lower hsg. has an oil seal incorporated into it which may be your leak. Make sure you use enough downward hand pressure to seat the seal--it will "pop" when seated. Use a little Merc. 2-4-C lube to assist it seating.
Rod: Are we still friends?  |
graham
Member
Username: holinwtr
Post Number: 67
Registered: 10-2006
| | Posted on Wednesday, May 07, 2008 - 09:59 am: |
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Thanks everyone for your input. It's good to know people in high places. You all have made fixing my old heap much easier. I'll start replacing seals and pressure testing. I'll check back with more questions I'm sure. |
Rod Stewart
Senior Member
Username: rod_stewart
Post Number: 1254
Registered: 08-2006
| | Posted on Wednesday, May 07, 2008 - 12:39 pm: |
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graham;
I have pondered this some more, and it does seem very odd that water could get into the drive oil just running on the muffs. This can normally only happen when the boat is sitting in water and there is a positive head of water pressure outside the drive.
The pressurized water from the pump runs upwards thru the water tube into a channel in the upper gearcase that circles around the upper gear cavity (to cool the upper gearcase), then directly thru the transom assembly via a hose, then to the engine. As such, there is no direct communication with the drive oil.
Looking at Rick's post, my comments on his possibilities (meaning no offense to you Rick):
#1; not very likely.
#2; possible; this seal needs to be checked and changed if in doubt
#3; not possible, there is no driving force to cause the oil to preferentially flow in this way
#4; possible; this seal needs to be checked and changed if in doubt
#2 and #4 are about the only way this could happen.
The only other possibility, and it seems remote, is if water somehow was left in the channel surrounding the upper gear cavity, and froze thus cracking the barrier between. Then the pressurized water in the channel would tend to enter the gearcase. I have never heard of this happening, but its possible I guess.
A pressure test is the only real way to tell what is going on.
Rod |
graham
Member
Username: holinwtr
Post Number: 68
Registered: 10-2006
| | Posted on Sunday, May 11, 2008 - 10:05 pm: |
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Rod, doesn't the water in the outdrive automatically drain out when the engine is shut off. That way there would be no water in the upper cavity? Just a thought. Correct me if wrong. |
Rod Stewart
Senior Member
Username: rod_stewart
Post Number: 1281
Registered: 08-2006
| | Posted on Monday, May 12, 2008 - 01:56 am: |
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graham;
Right. There is a tiny hole about 1 mm diameter in the very back of the baseplate under the pump. Its purpose is to drain the pump and the water tube and channel around the gear case. If it got plugged up with something however, it may not have drained, and it could then have frozen.
Like I said, never heard of it happening, but who knows?
Rod |
graham
Member
Username: holinwtr
Post Number: 69
Registered: 10-2006
| | Posted on Sunday, May 18, 2008 - 10:12 pm: |
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Well I've got everything back together now thanks inpart to all of you that were willing to share some of your knowledge. I also gained some knowledge of my own by doing it all myself. I'm really glad I did because now I have a better understanding of the inner-workings of my outdrive. All I have to do now is add some 80-90 gear oil, fire it up and see how bad I screwed things up. I would absolutely love to get it out this weekend and have a memorial day out on the water. It's supposed to be sunny and in the mid 70's. Perfect for this time of year. I'll check back if there are any other questions that arise. Thanks again |
