aq131a drive shaft bearing replacement

[Johneg13]

I have an 86 Volvo penta aq131a with a 275 od, I've got the outdrive off, shaft is sloppy, how do I replace the bearing, does the engine have to come out to remove the bell housing?

 

[Scott Danforth]

Search iboats for PDS bearing replacement. Many write ups, including part numbers for the 6000 series bearings. About $40 in seals and bearings

 

[dennis461]

..... does the engine have to come out to remove the bell housing?

I would think it is much easier with engine out (or lifted-moved forward). The six bolts trough transom plate to bell housing have to come out, and that's the majority of bolts. My boat has no room to attempt removal without pulling the engine.

Why not plan some other work while engine is out, new oil pan gasket, repaint oil pan, rear main seal...
Do you have motor mounts?

 

[Scott Danforth]

Pulling motor is a 45 minute job or less

 

[Johneg13]

no motor mounts, engine is held by the transom, if I take the six bolts out around the rear of the bell housing does that loosen the motor? do I need a picker to do that? I cant see how the motor is mounted, my manual is not very descriptive.

 

[Johneg13]

No Title

can the bearing come out this way?

 

[dennis461]

No Title

Page 91

http://www.rotationindex.at/images/transfer/Workshop Manual AQ171.pdf

You need a crane or such to hold the engine up while disconnecting from the sternplate.
Under the bellhousing there is a rubber bumper (on the stern plate) which fits into a socket on the bell housing plate, around 2" diameter, That holds up the motor and keeps the motor from spinning around in the bilge (without motor mounts, something has to keep the motor from rotating). The six bolts are holding a big rubber o-ring clamping the bell housing into a round hole.

 

[Johneg13]

thank you Dennis, not the news I wanted, but if the shaft is pressed in the housing there's no other option, I was hoping, removing the 2 snap rings the bearing would slide off the shaft, its an old boat, I'm afraid pulling the motor is going to open a can of worms, frankly the boat isn't worth $1500 in good condition. if I can get one summer out of it ill be happy. the bearing is not to sloppy, ima repack it and listen for it, thanks again

 

[PiratePast40]

The job is exactly the same with the engine out of the boat and the flywheel cover off as it is with the engine still in the boat. The shaft is NOT pressed in. Go to Harbor Freight and pick up a pair of long needle nose pliers and grind down the ends for a better fit deep into the housing.

If you wait for it to fail, it can cause some wild action with the shaft, physically breaking the flywheel housing snout, and possibly enough of an opening to allow flooding. That would be a really bad day.

As far as the value of the boat and maintenance. The hard truth is that it really doesn't matter what the boat is worth. They all require maintenance, and there is no price break on parts or labor based n the age of the boat.

 

[dennis461]

The job is exactly the same with the engine out of the boat and the flywheel cover off as it is with the engine still in the boat. The shaft is NOT pressed in. Go to Harbor Freight and pick up a pair of long needle nose pliers and grind down the ends for a better fit deep into the housing.

Not a job for beginners from the stern side of bell housing, you've got to clear all the corrosion from around the snap ring and get that out first.
Same as if the engine was already out.
The bearing IS pressed in, and until that is pulled out the shaft cannot come out. Which is why the manual says to press the shaft out from the engine side, it pushes the bearing out.

If possible one could pull the shaft from stern side) by grabbing the spine with a large vise grip or homemade pulling rig, hard to do inside the 'snout'.

​ The hard truth is that it really doesn't matter what the boat is worth. They all require maintenance, and there is no price break on parts or labor based n the age of the boat.

Very true.

 

[Scott Danforth]

I just replaced my PDS bearings. A gear wrench double-x snap ring pliers and the PDS housing on the work bench.

Either press in bearings, or heat PDS housing with heat gun, freeze bearing, then drop in.

Sequence is input side beaing goes in housing first (freeze bearing, heat pds housing). Drop bearing in, then add snap ring.
output end bearing put on shaft (heat bearing, freeze shaft). Then install shaft snap ring.
Put shaft and bearing in freezer, heat pds housing and installed bearing, after housing is about 200, shaft at 0, it will drop in. Add both snap rings.
Drive in seals.
Pump in grease
Reinstall pds housing, reinstall motor, reinstall drive

Attempting to run the bad bearing as shown will result in a catastrophic failure

 

[Johneg13]

Thanks to all, I will formulate a plan and update my progress,

 

[Scott Danforth]

here is a few links that may help

http://forums.iboats.com/forum/boat...55594-monterey-montura-newbie-need-help/page7

http://forums.iboats.com/forum/engi...ves/562871-volvo-penta-280-bellow-replacement

http://forums.iboats.com/forum/engi...rives/555898-270-bellows-replacement-surprise

 

[Johneg13]

Thanks Scott, very helpful, I keep seeing the words catastrophic failure, LOL don't want that, a tow is one thing, a rescue is quite another , I've got a pair of long shanked needle nose im going to machine to a pair of snap ring pliers, remove the rings and try an snatch the shaft out, is it advisable to drill and tap the aft end of the PDS so a slide hammer could attach?

 

[dennis461]

.... is it advisable to drill and tap the aft end of the PDS so a slide hammer could attach?

If you have a spare shaft in your back pocket.

I have had some success drilling and tapping things. I have also had failures, broken bits, broken taps, how would you get a broken tap out of the shaft? How much weaker is the shaft with a new hole in it?

Not to mention, the time it takes to drill and tap could be better used to pull the engine.
Remember, you do not have to pull it completely out of the boat.
Jury rig some 4x4 timbers on the beams and gunnel, raise engine about a foot high, and a foot forward.

 

[Johneg13]

No Title

so with these rings out, the bearing assembly doesn't look to come out the aft or does it need to be beaten out from the front -back, I'm not against pulling the motor just its an old boat and I don't want to damage it or open a whole can of worms

 

[Scott Danforth]

You press the shaft from the input side and it drives the shaft and bearing out the output side. Then you drive the input side bearing out with a drift. I used a chunk of oak and a 5# fist maul to drive my shaft/ bearing out and a drift to drive the bearing out

 

[Johneg13]

Thanks Scott, so with the bell housing on a bench, upside down, the shaft/ bearing will drive out of the aft end, then the bearing drives of the shaft once it's out of the housing and use prior instructions to reassemble. How is the shaft in the motor? Is it like the aft end just slides in the ujoint? Which probably is seized as well? By the way sea foam has a penetrating oil out that's what finally worked for me separating the outdrive from the boat.

 

[dennis461]

No Title

..... How is the shaft in the motor? .....

It is very similar to a shaft of a manual transmission in an automobile.
The shaft forward end has a necked-down section which fits into the crankshaft.
The crankshaft has a pilot bushing (Unless previous owner left it out.)
The forward end also has splines.
These forward splines grab a flex plate which is bolted to the flywheel.
(In an automobile, the clutch has the splines, the pressure plate bolts to the flywheel.)
In a boat, the flex plate with springs take some of the shock out of the driveline when you put the boat in gear.
The shaft does not rotate continuously in the crankshaft bushing(as a automobile manual transmission at a stop sign with foot on clutch pedal). It only moves a few degrees clockwise and counterclockwise to absorb shock.
The forward end is far enough from the water to have probably stayed in good condition.

Now, if the crankshaft bushing looks OK, reuse it with a bit of waterproof grease.
I did not have a bushing (previous mechanic was ignorant of the design).
Rather than buy or make a bushing, I used a sealed ball bearing which you can see in the picture.
The bushing to the right is from the automobile automatic transmission application which had a different internal diameter dimension. So I could not use it. (Third picture shows my bell housing with shaft still installed, and incorrect bushing hanging out.)

 

[Johneg13]

Thank you Dennis for the illumination