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Fitting aq280 “doughnut” seal clamping bolts

First off, these are 3/8" NC galvanized “Tap” bolts ...... (i.e., threaded the full length).

No O-rings required. The female threads within the flywheel cover dead-end.

To avoid future thread corrosion, coat the threads with a sealant. Quicksilver “Perfect Seal” works well.

Tighten evenly and in somewhat of a sequence.

The FWD rubber cushion ring (what you're calling a doughnut) provides the water seal, and should be new.
The AFT cushion ring can generally be re-used.

If you are installing a different engine, be sure to go through the triangulation process for the “one-time” initial Engine/flywheel cover alignment.

This would also be a great time to replace the PDS bearings.


By the way, your drive is an AQ series that incorporates main suspension fork/pivot tube geometry...... i.e., no Gimbal system!



If you would like to have help with the triangulation process, I'll post an image that will explain it.



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RicardoMarine said:
First of all, these are a galvanized “Tap” bolt...... (i.e., threaded the full length).

No O-rings required.

To avoid future thread corrosion, coat the threads with a sealant. Quicksilver “Perfect Seal” works well.

Tighten evenly and in somewhat of a sequence.

The inner rubber cushion ring provides the water seal, and should be new.

If you are installing a different engine, be sure to go through the triangulation process for the “one-time” initial Engine/flywheel cover alignment.

This would be a great time to replace the PDS bearings.


By the way, your drive is an AQ series that incorporates main suspension fork/pivot tube geometry...... i.e., no Gimbal system!


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Click to expand...

thanks, same engine, just been out for some maintaince and shaft bearing replacements, leg has had the upper section replaced as the lube pipe had failed due to corrosion, new steering helmet bushes, re sealed the dredded tilt cylinder (mine is a t drive) had a canvas boot made for the tilt fork to keep the water out of the hull esp when on moring for a few days

i couldnt actually remove the clamp ring bolts and had
to cut the heads off them with the gas torch, not much room in there
 
I'd like to see it so I know the shop aligned the engine right for my aq271c dual pds setup. Although now it has a new engine, but still the same gm350 block and 12-3/4" flywheel.
 
Here is an image that will help explain the initial alignment process.

You will notice 3 flat areas on the transom shield that will correspond to 3 flats on the flywheel cover.
The goal is to achieve equal distance between each 2 corresponding flats.

This is done by raising or lowering the front of the engine while the 6 AFT clamping collar bolts are not yet fully tightened.
(you can use a bit of silicone lubricant on the rubber cushion rings)

It may also involve shifting the engine towards Port or Starboard a bit.

The process involves the use of triangulation to create equal distance between the 3 groups of flats!

NOTE: the image shows a later model flywheel cover. The triangulation process is the same for ALL AQ series flywheel covers.


The last image shows an 18" grease gun extension hose being threaded into the flywheel cover. (typically about $8 at auto parts store)
The hose will be zipped tied up near the throttle cable for easy future access for lubricating the PDS bearings.

I suggest lubing these PDS bearings during each engine oil change, and with engine running at idle speed (dynamic -vs- static) !
 

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Not to hijack this thread, but how do you know when enough grease has been pumped into the PDS bearing lube port on the flywheel cover?
 
am_dew said:
Not to hijack this thread, but how do you know when enough grease has been pumped into the PDS bearing lube port on the flywheel cover?
Click to expand...

Excellent question.
It begins with with a pre-filled grease cavity when the new PDS bearing were installed.
We spin the PDS as the new grease is being pumped in. We stop ONLY when we see grease exit the AFT bearing ball cage.
This is done as to ensure that there are no air pockets within the grease cavity.

Once full, 4 to 5 to 6 future pumps are all that is required when the engine is at idle speed.


I once replaced PDS bearings only to find that the grease cavity had never been pre-filled.
In fact, the area was bone dry. :mad:
If you can believe it...... a well known V/P shop in Portland had done the work. :eek:
Fortunately, I was doing this as a preventative measure while doing other stern drive work.
Nothing other than bearing damage had yet occurred.
The owner was very lucky!


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am_dew said:
Thank you Rick!
Click to expand...

You are welcome.

A few more things that I forgot to mention:

...... as I explained, we pre-fill the grease cavity as we turn the PDS.
..... us a good high pressure grease (the marine wheel bearing grease is not the best for PDS bearings).
..... once you start with a certain type/brand grease, stay with that grease in the future (some greases are not chemically compatible with others)
...... this is done prior to installing the two 35x62x7mm seals.
..... only after seeing grease come through the ball cages, do we install the seals.
..... FWD seal installs conventionally, and should be glued and/or staked into position so that future grease cannot push it out of position.
..... AFT seal installs non-conventionally... (i.e., seal lip and tension spring facing AFT) we want this seal to breach any excessive grease.


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