Raw Water Leaking into Bell Housing

I have a 1985 Bayliner with an AQ225D. The boat has been out of the water for a couple years before I bought it. I serviced it, freshened up the tune, etc. Changed all fluids and dropped it in the water. I immediately noticed water coming into the Bilge. It is worse with the drive in the up position - slows down when in the down position the engine does NOT have to be running - I am relatively sure that this is not an issue with a leaky freeze plug behind the flywheel. I ran the boat for about an hour to check for any other issues - there were none. Engine and drive are smooth.
To diagnose the water leak I found the drive (u-joint) bellows was split. I pulled the drive unit out to replace the bellows. From what I can see, there is no way for the water to get into the bell housing except through the seals and bearings - is this correct?
Can the shaft/bearing be removed/serviced from the back of the boat without having to pull the engine and remove the bell housing. There is absolutely no rust/corrosion inside the housing so I can easily access the snap ring(s), but I am not sure that once I got the outer seal out, if the shaft can be removed.

Any insight would be very helpful

Thanks -

- New Guy Mike

From the looks of it ,I`d say no
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https://www.marinepartseurope.com/en/volvo-penta-explodedview-7743320-44-17257.aspx

I’ll try to give you detailed explanation in the morning.

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machiatto said:

I have a 1985 Bayliner with an AQ225D. The boat has been out of the water for a couple years before I bought it. I serviced it, freshened up the tune, etc. Changed all fluids and dropped it in the water. I immediately noticed water coming into the Bilge. It is worse with the drive in the up position -
The standard 280 is lift-out only. The 280 PT (as shown in the schematic) has power trim. Be careful when using the lift-out with the std 280.


slows down when in the down position the engine does NOT have to be running - I am relatively sure that this is not an issue with a leaky freeze plug behind the flywheel.
There will be 3 Welch plugs (casting core plugs) just ahead of the flywheel. 2 for coolant passages, and 1 at the camshaft bore.
Since the engine does not need to be running in order to see the leak, it's unlikely that the welch plugs are the offenders.
If while operating the engine on the trailer, garden hose and water muffs you DO NOT see the leak, that would further confirm that it's not an issue with the welch plugs.


I ran the boat for about an hour to check for any other issues - there were none. Engine and drive are smooth.
To diagnose the water leak I found the drive (u-joint) bellows was split.
Yep...... there is your culprit!
The drive shaft bellows is a wear item and must be routinely replaced.
To extend the life of the drive shaft bellows, never store the boat the with the drive in the UP position.
Instead, store it with the drive fully DOWN and aiming straight forward.

I pulled the drive unit out to replace the bellows.
You need to remove the transmission ONLY for this work.
If you removed the entire stern drive, re-install the lower unit and Intermediate housing as a unit.
Then install the transmission last.
Much much easier this way!

From what I can see, there is no way for the water to get into the bell housing except through the seals and bearings - is this correct?
A bellows breach will allow water into the Flywheel Cover (bell housing is an automotive term) PDS area. The water will travel through the female yoke splines and into the PDS bearing area. With the PDS spinning, the water will make it's way through the bearing ball cage and eventually into the flywheel cover interior.

Can the shaft/bearing be removed/serviced from the back of the boat without having to pull the engine and remove the bell housing.
If the boat has the original red, 1 pc flywheel cover, with a grease fitting at the 12:00 O'clock position, the answer is NO!
This flywheel cover arrangement uses a double bearing PDS. PDS = primary drive shaft.
The engine must be either removed, or slid forward and turned sideways, in order to gain access to the FWD PDS area.
With the 2 AFT snap rings removed, you will use a brass hammer (at the FWD side) to drive the PDS AFT and out.
The PDS will come out with the AFT bearing still attached to it.
You will then remove the FWD bearing snap ring, and then reach in from AFT and drive the FWD bearing out.
Replace the AFT bearing and re-install the PDS into the F/C.
Now install the FWD bearing, snap ring and seal.
Tip: either glue or stake this seal into place.
If you were to loose the FWD seal, no future grease will make it to/through the AFT bearing ball cage!
(see ** below)

NOTE: separate the engine from the flywheel cover, leaving the flywheel cover attached to the transom shield.
In other words, remove or slide forward/sideways the engine ONLY.

NOTE: remove the 4 lag bolts from the stringers, leaving the side engine mounts attached to the engine.

If the flywheel cover is charcoal gray and does not have a grease fitting, then yes....... the single bearing PDS can be removed without pulling the engine.


There is absolutely no rust/corrosion inside the housing so I can easily access the snap ring(s), but I am not sure that once I got the outer seal out, if the shaft can be removed.
Again, it will depend on which flywheel cover has been used.

Any insight would be very helpful

Mike, post more info and we can take it from there.

Click to expand...

Edit:

The double bearing PDS can use industry standard 6206 and 6007 bearings
Get these in a US, Japanese, German, etc, ..... NO Chinese bearings!

The seals will also be an industry standard 35X62X7mm in a TCM or a Timken w/ a single lip.
The AFT seal installs in the Non-Conventional direction.

** Be sure to spin the PDS while pre-filling the grease cavity before installing the AFT seal.
Use a good high pressure grease...... not the green Marine wheel bearing grease!
The single bearing PDS can use an industry standard 6206-2RS sealed bearing.

These will be the same parts as what you would get from Volvo Penta ...... at 1/3 the cost.



.

One more note!
Even if you suspect that the recent water intrusion has not harmed these beatings, it’s very likely that a replacement is over-due. A bearing failure here can cause severe damage that will be very expensive to repair!


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RicardoMarine said:

The AFT seal installs in the Non-Conventional direction.

Click to expand...

I appreciate all of the information thus far - truly !!!!
Is there a chance that you can expand on the statement above. I've watched a couple of YouTube videos and I have heard several people exclaim that as they take the Aft Seal out, they see that it was installed 'backwards'. From your comment, it sounds like what appears as 'backwards' is actually how it should be installed. Non Conventional Direction, I am hearing that this seal should be installed with the 'flat' side facing forward/in and the 'recessed' side facing aft/out (towards the transmission).
This makes it very difficult to get the yoke through the seal as the 'flat' side of the seal provides the taper for the yoke surface. Am I interpreting this correctly? Why is the seal installed different on either side of the housing. Again, any insight would be greatly appreciated.

- Mike

..............

machiatto said:

RicardoMarine said:

The AFT seal installs in the Non-Conventional direction.

Click to expand...

I appreciate all of the information thus far - truly !!!!
Is there a chance that you can expand on the statement above.
Yes.

I've watched a couple of YouTube videos and I have heard several people exclaim that as they take the Aft Seal out, they see that it was installed 'backwards'.
While there are quite a few good YouTube videos by knowledgeable people, be careful with the YouTube videos.
There is also quite a bit of mis-information out there.

From your comment, it sounds like what appears as 'backwards' is actually how it should be installed. Non Conventional Direction,
Yes...... non-conventional, as in opposite of how these would install conventionally.

This style seal actually gains sealing ability as pressure pushes on the inside, creating a further force into the sealing surface.
We DO NOT want the AFT seal to hold greater than the FWD seal holds.
Reason: as we service the PDS cavity with fresh grease, we want the AFT seal "to breach" any excessive grease volume or pressure.

If the AFT seal was to hold greater than the FWD seal, there is a risk that the grease gun pressure would push the FWD seal out of it's bore.
If we were to loose the FWD seal, we will have created a lessor resistance grease path. This means that no future grease will make it's way through the AFT bearing's ball cage.

In my 24+ years doing AQ service work, I have seen many of the front seals pushed out due to the AFT seal being installed incorrectly. In almost every case the AFT bearing was either bad or was about to fail due to lack of lubrication.
(see images below)

I am hearing that this seal should be installed with the 'flat' side facing forward/in and the 'recessed' side facing aft/out (towards the transmission).
Yes..... when installed correctly, you should be able to see the lip and lip tension spring while viewing it from AFT.

This makes it very difficult to get the yoke through the seal as the 'flat' side of the seal provides the taper for the yoke surface.
I have never experienced an issue.
Keep in mind that when removing the entire stern drive, the transmission is removed first, then the Intermediate housing with the lower unit.
When going back together, the Intermediate would be installed first, then the transmission last.
Replace all O-rings when doing so.

Am I interpreting this correctly? Why is the seal installed different on either side of the housing.
The FWD seal should hold against grease gun pressure, therefor it is installed in the conventional direction. It should be either glued or staked in place so that it is not easily pushed out by the grease gun pressure.

The AFT seal is NOT a water seal.... it is a debris seal and it holds grease against the AFT bearing's ball cage. It must be able to relieve excessive cavity pressure.
If you like the idea of installing the AFT seal as you think it should be installed, then drill a small hole into the metal seal body. The hole will relieve any excessive grease gun pressure. And again.... this is NOT a water seal. If you have water in this area, you have other and larger problems.

Also, when greasing the PDS bearings in the future, do so with the engine running at idle speed...... (dynamic -vs- static).

Questions:
Do you have the red 1 pc flywheel cover w/ grease fitting, the red B/W flywheel cover with the whitish colored B/W PDS adapter housing, or do you have the later charcoal gray flywheel cover w/o grease fitting?
1 pc red F/C = double bearing PDS
B/W F/C with the B/W PDS housing = double bearing PDS
1 pc charcoal gray F/C = single bearing PDS


And again, if you have the double bearing PDS, be sure to pre-fill the grease cavity while spinning the PDS, and prior to installing the AFT seal.
You will want to see and verify that the cavity is full.
If it is not full and purged of air pockets, any future 3, 4 or 5 pumps of grease may not reach the AFT bearing as you may think that it has.

Click to expand...

I've included a few of my images for you.
The last image shows an example of the damage that can occur from a failed AFT PDS bearing!
In extreme cases, this may include transmission damage.

So this has gone from bad to worse.

I have pulled the rear seal and while spinning the engine I have flushed the bearing with grease until all looks very fresh and clean. I decided to roll the dice and leave the bearings in the flywheel cover as-is - against your advice I realize - but the engine doesn't just move forward and to the side on this boat and I am (was) comfortable that the bearing is serviceable.

But I noticed that despite the u-joints appearing new, one has a tight spot, so I started replacing the u-joints and now have found that the intermediate section of the u-joint assembly is cracked where one of the cups pushes in. So then I started researching a new assembly and I am seeing that there is a 10 spline and a 26 spline. I need the 10 spline for my application, but now I am having concerns about the work that has been done on this drive in the past as this U-joint was definitely serviced with a cracked housing and left that way.

I do have the trans off as you suggested re-assembly would be easier, and it made servicing the U-joints easier as well. It would appear that water has never made it into the trans - it is spotless and since it also appears that no one has ever touched it, I am feeling good about the trans and drive assembly.

So - you have mentioned an updated (grey) flywheel cover, with an updated (or different in any case) shaft/bearing design. Does this updated FC use a 26 spline shaft, and if so, while I am spending way more than the boat is worth, is it advisable to update the FC and shaft assembly, and then get the updated U-joint assembly that uses 26 splines on the engine side and 19 splines on the trans side? Effectively updating everything up to the transmission. Or is properly (pull the engine and do it right) servicing the bearings on the shaft adequate?

And finally - any ideas on where to source this stuff reliably in terms of quality

Thanks Again -

- Mike

The charcoal gray flywheel cover PDS is fine spline.

I can sell you new complete Universal Drive shafts, in both course and fine spline yokes, if you are interested.

So it's a year later and the boat held up fine all season. I have it apart to replace the bearings/seals and u-joints/yoke assembly. The spindle (shaft) that the bearings press onto (#65 in your figure above, Volvo part number 839425) needs to be replaced. Is this something that you can provide/source/locate by any chance??

- Mike

I’ll post to this in the morning.

machiatto said:

So it's a year later and the boat held up fine all season. I have it apart to replace the bearings/seals and u-joints/yoke assembly. The spindle (shaft) that the bearings press onto (#65 in your figure above, Volvo part number 839425) needs to be replaced. Is this something that you can provide/source/locate by any chance??

- Mike

View attachment 20068

Click to expand...

That part is the PDS..... primary drive shaft. It is held in place within the Volvo Penta Flywheel Cover (bell housing is an automotive term).

The PDS alone will be shown as NLA (no longer available). I highly doubt that you can find a good used one by itself.
You should be able to find a complete Flywheel Cover (w/ PDS) on on e-bay.
And by the way..... that particular PDS is proprietary to the GM V-8 double bearing PDS flywheel cover.

Here is a fine spline unit.
https://www.ebay.com/itm/Volvo-Pent...536202?hash=item23bab8ea8a:g:7B8AAOSwVCpcKPU8

Here is a course spline unit.
https://www.ebay.com/itm/Volvo-Pent...565296?hash=item23b969aab0:g:R0kAAOSwgsla~Hqj


Not knowing what caused the PDS splined area to twist like that, yet knowing that it had to have been a severe impact force........ I would also replace the universal drive shaft (yoke ears and center section may be twisted also).
I do have a few of those (new) left if interested.

FWIW and FYI.... when/if you find a good used F/C, and even if the bearings feel good, I would replace them.
The damage that will result from PDS bearing failure will be very expensive.
(see my last image in post #8 again)

They are nothing more than industry standard 6206 and 6007 bearings.
About $14 each.
Use US, German, Japanese. No Chinese Bearings!!!!!!
The seal will be a single lip 35x62x7mm in a Timken or a TCM.

Be sure to pre-fill the grease cavity prior to installing the AFT seal.
Spin the PDS while pumping the new grease in!
As soon as you see grease coming through the ball cage, stop and install the AFT seal.
AFT seal installs in the Non-Conventional direction!



.

Thank You Ricardo - as always your insight and assistance is greatly appreciated. I was able to source a good used shaft from this place http://www.FrashWaterVolvoPentaParts.com. I have the PDS all assembled with new bearings and seals. I also purchased a new U-joint assembly because mine was cracked and welded. Everything went together wonderfully.

Thanks Again !!!!

First of all, you are very welcome. I'm glad to have been of help!

Make sure that you have "pre-filled" the PDS cavity (while spinning the PDS) just prior to installing the AFT seal.
If not pre-filled, you will not know how much future grease will be required in order to reach the bearings!
Also, when adding grease in the future, do so with the engine at idle speed. Dynamic -vs- Static!


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Hate to re-open this thread - but I have a question I am hoping someone will help me with. Since the repair referenced in the above thread, I have a vibration. It is most noticeable when standing near the transom while the boat is at speed, RPM's right about 3,000. But will increase or decrease with engine speed. Put your hand on the stern drive on the outside of the transom, or on the engine itself and you won't feel it, but standing on the deck it is very pronounced. EVERYONE I have talked to tells me it's an alignment issue with my gimbal bearing (which I believe this setup does not even use), but no one has been able to tell me what that 'alignment procedure' should be. With the two bearing PDS I don't see anyway that the shaft can be out of alignment from the engine. The flywheel cover houses both bearings and it also bolts directly to the engine block. Any adjustment of motor mounts and the flywheel cover along with both bearings are gonna follow ...
Am I missing something here? Was there an alignment procedure I should have performed?

............

machiatto said:

Hate to re-open this thread - but I have a question I am hoping someone will help me with. Since the repair referenced in the above thread, I have a vibration. It is most noticeable when standing near the transom while the boat is at speed, RPM is right about 3,000. But will increase or decrease with engine speed. Put your hand on the stern drive on the outside of the transom, or on the engine itself and you won't feel it, but standing on the deck it is very pronounced.

EVERYONE I have talked to tells me it's an alignment issue with my gimbal bearing (which I believe this setup does not even use),
Hopefully these people are not in the Marine repair business.
The AQ series Volvo Penta is of Main Suspension Fork/Pivot Tube geometry, and with fixed geometry between the engine and the stern drive universal shaft.
There is no gimbal ring, no gimbal housing and no gimbal bearing.


but no one has been able to tell me what that 'alignment procedure' should be.
The one-time engine alignment involves a triangulation procedure.
The goal is to achieve equal distance between 6 flats (groups of 2 each).

NOTE: Your flywheel cover will be red. The charcoal colored one shown here is a C and later flywheel cover.... but the info will be the same.


The engine is raised or lowered, or is moved towards Port or Stbd, to achieve the equal distance between each pair of flats.
Only then are the 6 cushion ring tap bolts fully tightened.

Since there is no Gimbal arrangement that requires alignment, the triangulation alignment has more to do with the complete and even compression of the two Rubber Cushion Rings.


With the two bearing PDS I don't see anyway that the shaft can be out of alignment from the engine.
Correct!

The flywheel cover houses both bearings and it also bolts directly to the engine block. Any adjustment of motor mounts and the flywheel cover along with both bearings are gonna follow ...
Exactly correct!

Am I missing something here? Was there an alignment procedure I should have performed?
See above.


As to the source of the vibration..... it's possibly a bad 6206 PDS bearing, bad drive shaft bearing crosses (u-joints), or even a twisted drive shaft component or a twisted PDS.

Click to expand...

Thank You Ricardo !!!
I did not check the used shaft I put in for run-out so I will assume for now that that is what the issue is. Everything else on your list is new.

Sigh.

Thanks Again