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Which ring cushion does the actual sealing on AQ drives?

W

Walleye4Days

Contributing Member
As the title says, which ring does the sealing to keep water out of the boat? I've done a lot of research on this, but I keep seeing answers for both the EXTERNAL and INTERNAL ring being superior to one another for sealing the water out... Some are sweating up and down the external ring does the sealing, while others swear up and down the internal/fore ring does the sealing... I'd just like to know once and for all which one does what, and what other purpose(s) they ultimately serve other than sealing.

So, which one is the most important one as far as keeping water out of the boat/getting a perfect long lasting seal? Also, does 5200/4200 or anything else need to be used on the rings or mating surfaces to compliment the ring cushion seals, or is it just built the seal up like a giant oring?

I'm trying to make dang sure I get this right, because I DEFINITELY don't want to have to do this procedure again.. EVER.. lol (it's been an absolute nightmare due to the previous owner painting over Anodes, thus, allowing literally everything to corrode all to hell and back. So, it's just been complicated and one headache after another during this rebuild.)
 
Both rubber cushion rings provide rear engine isolation..... I.E., rear engine mount.
The inner rubber cushion ring provides the water seal.

Both cushion rings need to be pliable and able to compress enough to do this.
Most often at least one ring should be new, and that would be the inner ring.
Better yet, replace both of them.

No sealant is required.
If anything, spray the rings with a silicone lubricant so they can nestle into position without being pinched or shifted.

Make sure that all six female threads (inside of the flywheel cover) are clean and greased.
Make sure that all six "tap bolts" are in good condition....... especially the hex heads.
(these are 3/8" NC galvanized tap bolts)

There will be a one-time alignment procedure that will need to be performed.
This will involve raising/lowering and/or sliding the engine towards Port or Stbd until we have equal distance between the 3 pairs of flats.
The clamping collar bolts (the tap bolts) will remain loose until alignment is achieved.

AQ series engine alignment 2 jpg.jpg



Here is a thread from several years ago on the same topic.

http://www.marineengine.com/boat-fo...the-standards-for-leveling-a-volvo-penta-351w



While you have the engine out, I would strongly suggest replacing your PDS bearings!





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Last edited:
RicardoMarine said:
Both rubber cushion rings provide rear engine isolation..... I.E., rear engine mount.
The inner rubber cushion ring provides the water seal.
Exactly what I was trying to figure out, thank you so much Rick! I have only one new ring at the moment, so I was debating what to do.

Both cushion rings need to be pliable and able to compress enough to do this.
Most often at least one ring should be new, and that would be the inner ring.
Better yet, replace both of them.
Welp, since you said it I just ordered another one from Michigan Motorz. Figured I may as well do it and it'll be one less thing I should have to ever worry about... Now, should I also remove the ransom housing and reseal it as well, or do they stay pretty well sealed up and once they're in, they're "in"? (I believe they 5200'd it in from what I see on the backside anyways. So, probably best to just leave a sleeping dog lay, haha)

No sealant is required.
If anything, spray the rings with a silicone lubricant so they can nestle into position without being pinched or shifted.

Make sure that all six female threads (inside of the flywheel cover) are clean and greased.
Make sure that all six "tap bolts" are in good condition....... especially the hex heads.
(these are 3/8" NC galvanized tap bolts)
I have looked literally EVERYWHERE for a bolt similar to what I need. But, every 4" galvanized tap bolt and other types of bolts I've found have only an inch or inch and a half of threading. But, my bolts are threaded up to about 2-1/2" and about 3/4 of that is inside the flywheel cover... So, should I get a shorter bolt around 3-1/2" or where can I find any of these without having to pay the ridiculous $10/each price for OEM bolts?

There will be a one-time alignment procedure that will need to be performed.
This will involve raising/lowering and/or sliding the engine towards Port or Stbd until we have equal distance between the 3 pairs of flats.
The clamping collar bolts (the tap bolts) will remain loose until alignment is achieved.
Does the alignment procedure need done even though I haven't removed the motor mount brackets from the mounting bolts? (I just removed the lag bolts holding the engine into the stringers, thinking that might save me an alignment procedure. But, I guess better be safe than sorry. Is there a specific tool I need to measure the flats' spacing, or just a simple CM/MM measuring stick?

View attachment 22823



Here is a thread from several years ago on the same topic.

http://www.marineengine.com/boat-fo...the-standards-for-leveling-a-volvo-penta-351w



While you have the engine out, I would strongly suggest replacing your PDS bearings!
FORTUNATELY, thanks to your help, I did the PDS bearings and seals in the middle of this past season. You helped walk me through it amazingly and I can't thank you enough for that. Now, I have to make sure this blockoff plate seals up. The blocking plate I bought ended up being the right part number, but the incorrect plate, as I have an AQ280DP-PT and it's for a generation newer or older where the relief holes are a little lower. So, I'm making my own plate. The only thing that worries me is that there's only about 3/16" worth of sealing space directly below where the exhaust hole cutout is. It makes me kinda nervous with that being the only thing keeping my boat from sinking, haha. Any suggestions?





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Click to expand...

Thanks again for all the help. I really need to send you out a thank you gift or something. You're knowledge and input has been invaluable to me during all these DIY procedures I've done on my boat. The words "thank you" can't even begin to Express my gratitude.
 
quote_icon.png
Originally Posted by RicardoMarine
Both rubber cushion rings provide rear engine isolation..... I.E., rear engine mount.
The inner rubber cushion ring provides the water seal.
Exactly what I was trying to figure out, thank you so much Rick! I have only one new ring at the moment, so I was debating what to do.
Use the new cushion ring against the flywheel cover, and use the best of the old ones for the AFT location.

Both cushion rings need to be pliable and able to compress enough to do this.
Most often at least one ring should be new, and that would be the inner ring.
Better yet, replace both of them.
Welp, since you said it I just ordered another one from Michigan Motorz. Figured I may as well do it and it'll be one less thing I should have to ever worry about... Now, should I also remove the ransom housing and reseal it as well, or do they stay pretty well sealed up and once they're in, they're "in"? (I believe they 5200'd it in from what I see on the backside anyways. So, probably best to just leave a sleeping dog lay, haha)
Tighten all six transom shield nuts. See how much they require. If they require quite a bit, then it may indicate that the transom core is soft.

No sealant is required.
If anything, spray the rings with a silicone lubricant so they can nestle into position without being pinched or shifted.

Make sure that all six female threads (inside of the flywheel cover) are clean and greased.
Make sure that all six "tap bolts" are in good condition....... especially the hex heads.
(these are 3/8" NC galvanized tap bolts)
I have looked literally EVERYWHERE for a bolt similar to what I need. But, every 4" galvanized tap bolt and other types of bolts I've found have only an inch or inch and a half of threading. But, my bolts are threaded up to about 2-1/2" and about 3/4 of that is inside the flywheel cover... So, should I get a shorter bolt around 3-1/2" or where can I find any of these without having to pay the ridiculous $10/each price for OEM bolts?
A good Fastener Supply Company should be able to bring in the correct "Tap" Bolts for you.

There will be a one-time alignment procedure that will need to be performed.
This will involve raising/lowering and/or sliding the engine towards Port or Stbd until we have equal distance between the 3 pairs of flats.
The clamping collar bolts (the tap bolts) will remain loose until alignment is achieved.
Does the alignment procedure need done even though I haven't removed the motor mount brackets from the mounting bolts? (I just removed the lag bolts holding the engine into the stringers, thinking that might save me an alignment procedure. But, I guess better be safe than sorry. Is there a specific tool I need to measure the flats' spacing, or just a simple CM/MM measuring stick?
Pulling the lag bolts only, and leaving the engine mounts attached to the cylinder block, was the correct way to do it.
No... no special tool is needed, although Volvo Penta lists one.


Here is a thread from several years ago on the same topic.

http://www.marineengine.com/boat-for...lvo-penta-351w


While you have the engine out, I would strongly suggest replacing your PDS bearings!
FORTUNATELY, thanks to your help, I did the PDS bearings and seals in the middle of this past season. You helped walk me through it amazingly and I can't thank you enough for that. Now, I have to make sure this blockoff plate seals up. The blocking plate I bought ended up being the right part number, but the incorrect plate, as I have an AQ280DP-PT and it's for a generation newer or older where the relief holes are a little lower. So, I'm making my own plate. The only thing that worries me is that there's only about 3/16" worth of sealing space directly below where the exhaust hole cutout is. It makes me kinda nervous with that being the only thing keeping my boat from sinking, haha. Any suggestions?
I would need to see a few photos of this.





Thanks again for all the help. I really need to send you out a thank you gift or something. You're knowledge and input has been invaluable to me during all these DIY procedures I've done on my boat. The words "thank you" can't even begin to Express my gratitude.

Your thank you is enough..... I'm glad to have helped.
 
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