1979 Volvo 350/280 PDS bearing: impending failure, risk of operation, drive identification

Dreadnought said:

............... Boat is a twin 350/280 VP drive in an IMP Kansa, circa 1979.

Port engine has a rattle you cannot hear at idle, but starts to get audible about 1200 rpm in neutral on the trailer, other engine is off. I am told it is the output shaft bearings (PDS I assume).
Yes... PDS = Primary Drive Shaft.
This shaft connects the engine's Borg Warner drive coupler to the transmission's universal drive shaft.
Very likely the PDS bearings have gone bad. This typically occurs from lack of service and/or age.

My bell housing has a capscrew on the grease port, after reading the posts, I intend to get a zerk here and grease it up, running, and listen for improvement.

Instead of doing a grease zerk directly into the flywheel cover, use an 18" grease gun extension hose (1/8" TP) with a 1/8" coupler and zerk at the upper end.
Zip tie this to the throttle cable bracket, and you won't be as likely to forget it this way!

After each oil change, and while the engine is idling, give it a few pumps of new grease. (dynamic -vs- static)



If the "Flywheel Cover" has the grease cap at the 12:00 O'clock position, I can just about assure you that you have the double bearing PDS.
The double bearing PDS is not accessible without removing the engine, or at least sliding it forward and sideways a bit.


Questions:

1) Any possible guess on if I can get another 20 min run time?
It all depends on how bad the AFT bearing is, and how aggressively you make a turn at planing speed.

Is this an instant catastrophic failure, or does it increase in volume, and allow time to shut it down before ventilating the housing?
Again, it will depend on how bad the AFT bearing is and how aggressively you make a turn at speed.

During my years of AQ series repair work, I have seen anything from very light scoring at the interior of the flywheel cover snout, to severe damage that has taken out the snout, damaged the PDS, damaged the universal shaft......, and if severe enough, I've seen the front transmission collar broken.
All of this damage is expensive to repair.
It is much less expensive to remove the engine and to replace the two bearings.

2) For bearing replacement, does the engine need to be removed on all the 280 drives,
No, and it's not necessarily related to the drive. It's very much related to the type of flywheel cover and type of PDS.
All inline 4 and 6 cylinder engines, and the later GM V-8 engines used a single bearing PDS.
The inline 4 and 6 cylinder engines will offer the grease port (open bearings)
The GM V-8 will not offer the grease port (sealed bearing)
Any of the single bearing PDSs can be removed from AFT without removing the engine!

and if not how do I tell?
For a GM V-8, if the flywheel cover offers the grease port (such as yours does), it will be equipped with the double bearing PDS.
Engine must be removed for PDS access and bearing replacement.

For most all Ford V-8s and the later GM V-8s (charcoal gray flywheel cover), you won't see the grease port.
This PDS is single bearing and can be accessed from AFT witout engine removal.


If you have the red 1pc flywheel cover, or if you have the red Borg Warner flywheel cover with the aquamatic gray Borg Warner - slash - volvo penta PDS adapter housing, the bearings and seals will be:
1..... 6206 open bearing
1..... 6007 open bearing
2..... 35x62x7mm single lip TCM or Timken seals

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kimcrwbr1 said:

Just a FYI do not run the engines in neutral for extended periods. The gearoil slinger is on the propshaft and running in neutral can damage the upper gearbox bearings especially if low on gearoil. It must be in gear to pump the oil into the upper part of the upper gearbox. QUOTE]

Thanks for the tip - I have much to learn on these drives. Question - besides the prop hazard which I can protect against, any issue in running the drive in forward, slowly, on the trailer? Seems like as long as I have good water pressure on the rabbit ears, it should be OK and help lube the upper bearings.

Thanks

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kimcrwbr1 said:

Just a FYI do not run the engines in neutral for extended periods. The gearoil slinger is on the propshaft and running in neutral can damage the upper gearbox bearings especially if low on gearoil. It must be in gear to pump the oil into the upper part of the upper gearbox.

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kimcrwbr1 said:

http://www.ebay.com/itm/VOLVO-PENTA...ash=item2a813cc40b:g:6nYAAOSwEK9T5UGx&vxp=mtr

That is a non-OEM part copied after the later model transmission stress proof steel split ring keepers. This replacement part is required for the earlier transmission vertical shafts because the later OEM stress proof steel keepers will not work. (shaft diameter increase)
These are being offered by DC in California who actually copied my idea for these.
I had 100 or so made years ago. I sell mine for $50 plus the shipping cost.


You just need to get the right nut for the proper end play on the verticle shaft. #839332-3-4
More importantly is the brass split ring keeper at the lower area of the transmission vertical shaft.

This OEM brass split ring keeper "checks" upward force on the vertical shaft. As the brass keeper begins to expand, up/down end play becomes dangerously excessvie. If not attended to, the expansion contiues until the keeper can no longer retain upward force.
When/if the keeper was to let go, the vertical shaft is pushed upwards and out the top cover.
(see DC's image of broken top cover below).
I have repaired several of these over the years..... all from not replacing a $60 part during a re-seal!

If further adjustment is necessary once the new stress proof steel keeper is installed, we can also add a shim between the bronze spacer and the actual nut as to reduce the clearance. (the bronze spacer can be removed from the nut, and can be replaced with the shim stock between).
Or ..... if the clearance is too tight, some material can be carefully and accurately removed from the bronze spacer.

Either works!

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Dreadnought said:

kimcrwbr1 said:

Just a FYI do not run the engines in neutral for extended periods. The gearoil slinger is on the propshaft and running in neutral can damage the upper gearbox bearings especially if low on gearoil. It must be in gear to pump the oil into the upper part of the upper gearbox.

Click to expand...

Thanks for the tip - I have much to learn on these drives. Question - besides the prop hazard which I can protect against, any issue in running the drive in forward, slowly, on the trailer? Seems like as long as I have good water pressure on the rabbit ears, it should be OK and help lube the upper bearings.
See my above explanation.
You can operate the engine while on the garden hose and water muffs.

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kimcrwbr1 said:

When your running on the muffs there is a hole on the bottom of the gearbox you can plug and give you better flow to the raw water pump. You dont want to run past high idle speed on the muffs. Do all the fine tuning on the water!

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