Volvo Penta AQ290A with 280 PT Lower Unit

[1981Century]

Hey everyone!

Excellent forum here, I've learned a lot about the 280 so far. Unfortunately it's been hard finding information specific to the AQ290 engine. I've had this for about a year, it looks to be a 1979, installed in a 1981 Century 4000.

A couple things...

I have a ton of play in the steering. In doing some checking and reading I discovered that it's likely the steering fork bushings are worn. I was able to grab the steering helmet and move the entire drive side to side about a quarter inch. I also noticed that my helmet to to the top of the drive is loose as well. What are the part numbers for each bushing plus the water seal? I was unable to find them on the VP website.

As far as the PDS and bearings, I still haven't identified the flywheel cover on mine...I really hope it's a single bearing accessable from the rear...

Secondary to that, is there a good start to finish guide on setting timing and dwell for the AQ290? Looks like just a base setting of 8 deg btdc at 600RPM? I'm sending the original QJet off to Cliffs performance for a rebuild.

Thank you.

 

[RicardoMarine]

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Hey everyone!

Excellent forum here, I've learned a lot about the 280 so far. Unfortunately it's been hard finding information specific to the AQ290 engine.
The 290 refers to the stern drive.
The 1979 Volvo Penta GM engine would be an AQ260, AQ260A, AQ200B, AQ225, AQ200, etc.

And by the way, the 290 was not available in 1979, and I do not believe that the 280PT was available in 1979.


I have a ton of play in the steering. In doing some checking and reading I discovered that it's likely the steering fork bushings are worn.
Very likely.
These would be the collar steering fork shaft bushings.
Pay close attention to the orientation of the spindle arm and the collar steering fork shaft..... the indexing of these controls the Port to Stbd steering stops.

I was able to grab the steering helmet and move the entire drive side to side about a quarter inch. I also noticed that my helmet to to the top of the drive is loose as well. What are the part numbers for each bushing plus the water seal? I was unable to find them on the VP website.
Things may have been replaced or updated. Pictures would be very helpful.

As far as the PDS and bearings, I still haven't identified the flywheel cover on mine...I really hope it's a single bearing accessable from the rear...
If it is a red 1 pc, or a red B/W flywheel cover with the aquamatic white B/W PDS adapter housing, it will have the double bearing PDS.
If it is a later model 1 pc charcoal gray flywheel cover, it will be a single bearing PDS. (same with the Ford engines)
Either way, the PDS is removed from AFT...... it's just that the double bearing PDS requires front access..... which means the engine needs to be pulled.

Secondary to that, is there a good start to finish guide on setting timing and dwell for the AQ290? Looks like just a base setting of 8 deg btdc at 600RPM? I'm sending the original QJet off to Cliffs performance for a rebuild.
In the CW direction from the TDC slot, mark off the harmonic balancer up to 35*.
Set BASE advance, and then increase RPM up to approx 3,200 rpm while strobing the timing marks.
You should see a rather linear curve with approx 28* Full In at 3,200 rpm.

Thank you.

.

 

[1981Century]

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Thank you very much for the quick reply. I have a few things here that should help us identify what is needed.


Steering Helmet /fork shaft play:

Inside View of steering component play:

Helmet bolts and side to side play:

Engine Identification:


Outdrive identification:


I confirmed that my flywheel cover is the two PDS bearing type, but this one has a screw at the 12 o clock position instead of a grease fitting. I only have slight vibration when turning sharp, equal either direction. U Joints were done by the previous owner a couple years ago.

 

[RicardoMarine]

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Thank you very much for the quick reply. I have a few things here that should help us identify what is needed.

Steering Helmet /fork shaft play:

Inside View of steering component play:

Helmet bolts and side to side play:

From what I see you do have excessive play at those areas.

Engine Identification:
View attachment 20232

Outdrive identification:
View attachment 20233

An array of these covers are interchangeable....... 250, 270, 280, 285, 275, etc.
While it does appear that you have the 280PT, the cover is not always an accurate means of determining the drive model number.

I confirmed that my flywheel cover is the two PDS bearing type, but this one has a screw at the 12 o clock position instead of a grease fitting.
That would be an early F/C. The threads for that part are machine threads.
Two choices:
Find a short brass 3/8" bolt and drill/thread it for a zerk fitting.
Run a 1/8" TP tap into the hole, clean out the shavings, and install a 1/8" TP zerk fitting.

I only have slight vibration when turning sharp, equal either direction. U Joints were done by the previous owner a couple years ago.

A failure here can be very damaging and very costly.
common damages due to bearing failure:
PDS wobbles and causes the universal drive shaft to take out the flywheel cover bellows snout.
PDS itself becomes damaged.
PDS wobbles enough to damage the universal drive shaft.
Universal drive shaft damages the FWD transmission collar.


My suggestion:
If no history of the PDS bearings having been replaced, I would certainly change them.
Be sure to pre-fill the grease cavity while the PDS is being turned.
Pre-fill until you see new grease coming through the AFT bearing ball cage.
Only then will the AFT seal be installed, and it installs in the non-conventional direction!

When you lube them in the future (during engine oil changes), do so with the engine at idle. Dynamic -vs- Static!

Once changed, and when lubricated routinely, they will last for another 15 years or so.

 

[1981Century]

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I will certainly take your advice on the PDS bearings. I have a garage I can back the boat into, and hoist the engine up and back off the flywheel cover to gain access. I take it as long as I don't disturb the engine mount riser height, everything should bolt back together fine? I've found plenty of info from Ricardo on the rest of the procedure in older threads, much appreciated.

As far as the loose steering, it looks like I need 2 bushings for the steering fork shaft, 853861, 853862, and ring 839195. Easy enough


For the helmet, I see two different bushing versions. Mine looks like the old set up with two holes, but due to the side to side play, is there an insert/bushing combination to upgrade to? I see a stainless steel insert threaded into the helmet that is available (853048?), and then the bushing that is inserted into the helmet, held down by two allen head screws. Any advice would be appreciated!

Thanks again.

 

[RicardoMarine]

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I will certainly take your advice on the PDS bearings. I have a garage I can back the boat into, and hoist the engine up and back off the flywheel cover to gain access. I take it as long as I don't disturb the engine mount riser height, everything should bolt back together fine?
In theory..... yes!

I've found plenty of info from Ricardo on the rest of the procedure in older threads, much appreciated.
Glad it was helpful.

As far as the loose steering, it looks like I need 2 bushings for the steering fork shaft, 853861, 853862, and ring 839195. Easy enough
You will need to remove the helmet, remove the transmission (watch for the shims), and then loosen the spindle arm pinch bolt.
If need be, you can drive wooden wedges between the upper area of the steering fork and transom shield. This will help pull the steering fork down and out.
NOTE:
The spindle arm and collar steering fork are splined to each other.
Their indexing controls the lock-to-lock steering stops.
Before removing, punch marks into each one as to ensure the correct indexing when going back together.

Suggestion: increase the length of the pinch bolt expansion/compression slot. This helps the pinch bolt do it's job.


For the helmet, I see two different bushing versions.
Actually, there are more than 3.

Mine looks like the old set up with two holes,
That would be the later version 2 bolt helmet pin!

but due to the side to side play, is there an insert/bushing combination to upgrade to? I see a stainless steel insert threaded into the helmet that is available (853048?),
It's actually a chrome plated brass bushing!

and then the bushing that is inserted into the helmet, held down by two allen head screws.
Again, that would be your 2 bolt helmet pin. It does not hold the bushing in place. That bushing is threaded into the helmet.

Here's the problem with trying to replace that bushing:
The aluminum threads within the helmet are very likely corroded. When you remove that bushing, use heat on the helmet prior to attempting.
It the old bushing comes out, look closely at the female threads.
If they are OK, then a new bushing may be successful.
Be sure to use a loc-tite product on the threads.

Any advice would be appreciated!

Thanks again.

 

[1981Century]

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Update!

I ordered all new parts. Helmet pin, helmet pin bushing, drive bellows, basically everything I think needed replacing to take out the side to side play and make her water tight. I'll get to the PDS eventually. This is a freshwater boat, I'm very fortunate to not encounter any severe corrosion. UJoints were in excellent condition and there was no presence of water.

Now...I'm about to attempt removal of the steering helmet bushing, the old one was very well worn to the point where the brass was showing. I know in a previous response, you mentioned using heat. What is the best tool to use so that I can get a bite on the ring cutouts to spin this sucker out? I was thinking a piece of rectangular plate steel that is the width of the ring cutouts on the steering helmet bushing, and welding a heavy threaded rod to the center. ANY techniques and tools used would be helpful. I want to try to save the helmet if I can!

Thanks a ton.

 

[RicardoMarine]

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Now...I'm about to attempt removal of the steering helmet bushing, the old one was very well worn to the point where the brass was showing. I know in a previous response, you mentioned using heat.
Yes.... either Propane or Mapp Gas in a small hand held torch. NO Oxy/Acet...... too hot, and too much oxygen for heating aluminum!

What is the best tool to use so that I can get a bite on the ring cutouts to spin this sucker out? I was thinking a piece of rectangular plate steel that is the width of the ring cutouts on the steering helmet bushing, and welding a heavy threaded rod to the center. ANY techniques and tools used would be helpful. I want to try to save the helmet if I can!
Well, the tool used would be a spanner wrench of sorts. I do not believe that Volvo Penta offered this tool.

You may need to find or make a steel tube that fits nicely into the ID of the bushing.
Then drill a perpendicular hole in it for a piece of square stock that will fit tightly into the bushing's two spanner wrench slots.
The square stock will be silver soldered to the tube.
You would also need to create a hex area for a socket to fit onto.

Heat the helmet prior to attempting to remove the bushing.
The aluminum threads may be damaged from corrosion, and is why a bushing replacement doesn't always work as a fix.

If you are able to remove the old bushing, wire brush the aluminum threads clean. Examine them carefully (often they will be corroded).
If they are OK, prime both the female and male threads (to remove any oil/grease products), and apply a good hardening thread-locking product as you install and tighten the new bushing.

 

[1981Century]

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Excellent idea for building a removal tool! I'll update progress on that helmet bushing in a couple days.

Anyone have grease suggestions? I'm thinking about using Johnson Triple Guard (blue stuff) for the steering fork shaft grease, reinsertion of the drive pivot pins, and other pivot areas. For the U-Joints, I'm thinking Lucas Red n Tacky to match the wheel bearings I just renewed. It looks like it has good water resistance, and the Triple Guard wont work for U Joints anyway.

 

[RicardoMarine]

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Excellent idea for building a removal tool! I'll update progress on that helmet bushing in a couple days.
I hope that it works for you.

Anyone have grease suggestions? I'm thinking about using Johnson Triple Guard (blue stuff) for the steering fork shaft grease, reinsertion of the drive pivot pins, and other pivot areas.
**Whatever you use, stay with the same grease in the future...... some greases have comparability issues in that when mixing un-like grease chemistry, the grease may loose it's viscosity and may turn liquid like. (I've seen this happen)
I use a high pressure grease.

As for the collar steering fork, take a small piece of rubber and clamp it over one of the tiny shaft grease passages.
Apply grease to the top grease fitting.... it will blow out and clear the old hardened grease from the passage.
Do same to the other passage!
NOTE: the factory installed these two bushings with some type of epoxy. If you can do same, it will help prevent water intrusion in/around the OD of the bushings.... of which can cause the aluminum to corrode, expand and squeeze the bushings onto the fork shaft, which in turn will make for eventual stiff steering.

As for the suspension fork hinge pins..... yes, grease the bores and pins before installing.
Do same for the hinge pin lock bolt threads.

For the U-Joints, I'm thinking Lucas Red n Tacky to match the wheel bearings I just renewed. It looks like it has good water resistance, and the Triple Guard wont work for U Joints anyway.
I use a high pressure grease for the bearing crosses (u-joints).
See ** above.


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

.

 

[1981Century]

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I found what looks like the trim sending unit wire....I have absolutely no clue where it attaches to the drive. I don't see a set screw on the drive or anything. Any ideas?