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SP C Outdrive leaking lube under shift shaft cover? See pics please

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cybrdweeb

Member
We took our new (new to us) 1992 Excel 20SL out for it's maiden voyage this weekend and had a great time and it ran beautifully.

Unfortunatly the fun ended when I got home and parked it and later found a small puddle of lube under the outdrive. When I lowered the drive and took the front shifter cover off it had a lot of lube inside and it was running down the leg when it was up.

I'ts a Volvo Penta SP C drive. I pulled the dipstick in the top and it was way over full so I thought oh no- got water inside. I pulled the drain plug and to my relief it was clear with no signs of water mixing. I had changed the lube a couple weeks ago so maybe I overfilled.

I drained the fluid to the proper level, cleaned everythinng off real well and ran it on the muffs and watched for leaks- especially the shift shaft seal. I never saw a leak and it hasn't leaked at all since then.

The oil under the cover had to come from some where so I'm still concerned- what should I do next?
 

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3 o-rings and one seal could put oil there. Top O-ring is a special deal that I have seen leak before. The o-ring around the shifter is a good possibility also. the last o-ring is the one between the upper gear and the mid housing but your oil looks to be a bit higher on the drive. The seal you mentioned is the most likely candidate. Clean it all up and run it on the hose, in gear, look for signs. Leave the cover off.
 
Thanks Gary- if the fluid was over full and the outdrive was hot from running would it build pressure and force fluid out the shift shaft seal? I read somewhere that the shift seal has a lip that can let lube out under pressure but that may have been somebodys own idea. The reason I ask that is because there is no water contamination in the lube so water doesn't appear to be getting in but gear lube is getting out somehow.
 
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The oil is not hydrogenated.... I can tell from the color.
You said that the drive was over-filled.
Without the correct air space above the upper gears, expansion can cause over-pressure.
Look closely at your photo. Am I seeing oil leading up the eccentric piston seal?

If so, I'll bet that is where it's leaking from.


Drain the oil, and perform a Pressure/Vacuum leak down test, and see how long she'll hold in both directions.


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There was some oil around the eccentric seal so I cleaned everything good and ran it for about 5 minutes on the hose and no leaks returned but It may ony occur when it gets hot. I'll just have to check after the next trip out and if it leaks again I'll have it pressure tested. Is it possible to pressure test with the outdrive on or does it have to come off?
 
cybrdweeb said:
There was some oil around the eccentric seal so I cleaned everything good and ran it for about 5 minutes on the hose and no leaks returned but It may ony occur when it gets hot. I'll just have to check after the next trip out and if it leaks again I'll have it pressure tested. Is it possible to pressure test with the outdrive on or does it have to come off?
Click to expand...
Running while on the garden hose and muffs, will not generate the same amount of heat, therefor you'll likely not see the same amount of potential expansion.
Expansion will generally force gear oil out if the seals are bad enough.
Contraction upon cooling, will generally pull water back in.... and again, if the seals are bad enough.

Yes, you can do the Pressure/Vacuum leak down test with the drive installed.
The advantage with the drive removed, is that we can rotate the main shaft, in addition to rotating the eccentric piston and prop shaft while under Pressure/Vacuum.

Just an FYI... the eccentric piston seal (for reasons that I can't quite explain) is more prone to failing.
Prop shaft seals may be next.
Main drive gear seals can go un-noticed because the lost oil is within the drive shaft bellows.

Nonetheless, the test will reveal a leak if you have one..... you just may not where.


FYI #2, testers can leak also, so check your tester and tester connection.


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I pulled the shifter cover off last night and sure enough there was a little lube right under the shift shaft seal.

Looks like I'll be replacing the seal. Should I replace the large O-ring behind the plate as well and should I order new roll pins as well?

Any tips on replacing the seal would be greatly appreciated.
 

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cybrdweeb said:
I pulled the shifter cover off last night and sure enough there was a little lube right under the shift shaft seal.

Looks like I'll be replacing the seal. Should I replace the large O-ring behind the plate as well and should I order new roll pins as well?

Any tips on replacing the seal would be greatly appreciated.
Click to expand...
Yes.... a few tips.

New O-rings every time these are taken apart..... O-rings rarely go second time around.


There is a spring pin that holds the Neutral detent pin in place.
With your later drive, this spring pin will be installed parallel with the eccentric piston.

See note #10 here.
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This means that you'll need to drive the spring pin in deeper, in order to release the Neutral detent pin.
You'll need a small straight shank pin punch tool just under the size of the pin bore, and make sure it's long enough.
Once you punch the old pin through, the Neutral detent pin is ready to be pulled out.

Now... here's the trick or point of failure for some.
The existing spring pin must be removed from the bore within the eccentric piston. If not removed, the next guy in won't be able to drive the current spring pin through.
Spray carb cleaner into the bore to dilute the oil film, and gently tap the piston on a wooden surface.
The spring pin should fall out.
A new spring pin would be best, but I've found that you can ever so slightly expand one end of the joint where the spring pin comes together. (sharp pointy chisel works)
This gives you a leading edge, yet offers a friction fit when driven back into the correct depth.



**NOTE: There may be a second source of detents.
If you see the larger eccentric piston detent springs, you'll want to shove a socket into the eccentric piston bore as you remove the eccentric piston.
This keeps the detent springs and balls in place.
They are showing one single spring here, but are not showing the steel balls.
You may not have these.




Here's the older style.

Note the chamfered bore in the side of the eccentric piston... this is what I'm refering to in ** above, and the balls "detent" into this bore.

This spring pin is perpendicular to the piston body.
There are two open holes in the housing for removing this style.

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These are easy to push out.
Once out, the Neutral detent pin can be removed.



As for the new seal, nothing out of the ordinary, with exception to these being "directional".
This exposed metal portion faces towards the oil side.

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I use a sharp chisel type tool to carefully carve out the old seal from the housing.


You'll need something to push on the new seal.
If you have an old AQ series drive single prop spacer laying around, these are the perfect diameter for a pressing fixture.
Clean up any sharp edges first.
You can use your bench vice jaws to press the new seal in. This keeps everything square and aligned.
I use Perfect Seal when installing the new one.


Polish the piston with emery cloth in a shoe shine fashion.
Grease coat the seal between the two lips.


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Funny but you wont buy much on my card- like many boat owners most of money goes either to repairs or gas money- regular is $4.15 a gallon here in Michigan and thats not marina prices.
 
I ordered the parts and have been reading the service manual- it specifies shimmiing the shimming screw and you didnt mention anything about that- is it necessary?
 
cybrdweeb said:
and have been reading the service manual- it specifies shimmiing the shimming screw and you didnt mention anything about that- is it necessary?
Click to expand...
If you've made no changes to it, NO!

Perhaps check the tension on the bolt.
It must squeeze the SS shim washers for a water tight seal.


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I got the new seal installed in the housing and am ready to put back in the outdrive.

Should I put some grease on the shift shoe contact surface?
 
cybrdweeb said:
I got the new seal installed in the housing and am ready to put back in the outdrive.

Should I put some grease on the shift shoe contact surface?
Click to expand...
No need to!
After you've filled the drive with engine oil, this will become wet the moment that the engine fires up.


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geez I feel a little stupid now- guess I didnt think that one through very well.:rolleyes:

You mentioned "engine oil" - is that what I should be using in the SP C? I've read conflicting opinions whether it should be engine oil or synthetic gear lube. It has gear lube in it now.
 
Heavy gear lube can/may damage the slinger pump drive pins. If you loose the impeller drive pins, you'll loose transmisssion cooling.

Look at your OEM service manual for the correct type and weight oil.

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About to attempt this as I bought a new boat and its leaking ... I got the shift seal from volvo , but forgot to get the O ring... will have to pick that up as well !

You will have to excuse me as I am not that familiar with Volvo legs,

Do you do this with the leg trimmed up (to prevent a bunch of oil from spilling out) ? or does it have to be down and just refilled after ?

Is there any specific torqueing that needs to be done on any of these bolts ?
 
mrchadburn said:
Do you do this with the leg trimmed up (to prevent a bunch of oil from spilling out) ? or does it have to be down and just refilled after ?

Is there any specific torqueing that needs to be done on any of these bolts ?
Click to expand...
If you raise the drive full UP, you'll still loose some oil, but not too much. Re-fill when finished with the seal replacement.

Only four 1/4" SS bolts are involved. Be gentle with each... and definitely replace this O-ring.


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RicardoMarine said:
If you raise the drive full UP, you'll still loose some oil, but not too much. Re-fill when finished with the seal replacement.

Only four 1/4" SS bolts are involved. Be gentle with each... and definitely replace this O-ring.


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Click to expand...


Thanks Ric, I have got the O-ring. In the leg manual is says to seal with permatex... did you do that ? from a quick google search it looks like a gasket maker type material ? I have some gasket maker i used for motorcycles ... should I get some " marine grade stuff' ???
 
No gasket..... greased O-ring only, or Perfect Seal on the O-ring.
The housing and gear case will come into contact..... O-ring seals it.
 
Hello Ricardo, I came across this old post as I'm dealing with and researching this same, shift shaft seal, issue now. I'm confident I will be able to replace this myself but am wondering if you could tell me, what are the symptoms of performance when this seal gets a leak? I've noticed lately, reverse is not engaging right away and now forward is acting the same. I have to give it a little throttle before it will engage. Also, intermittently, when I increase throttle to get on plane, the engine seems to bog and won't increase speed. After a couple of tries, I can get it to react properly. Are these different issues or could this happen due to a bad seal? Maybe I'm totally off base all together. Thanks for any input. I have twin volvo penta 5.7gsi motors.
 
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