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VP 270 Outdrive Will Not Engage Forward or Reverse

N

npwiesne

New member
1980 Bayliner Explorer
Volvo Penta AQ120B
270 Outdrive

I picked this boat up this summer and it has been a great teaching experience for my children on setting points, rebuilding carbs, impellers and the general joys of boat ownership. I also taught them to ski and when it was finally my turn to show them how it was done the boat lost power to the outdrive after pulling my up. Any thoughts or advice on how to narrow down the issue are greatly appreciated. I’ve scoured existing threads and come up with a few questions based on what I’ve read so far.

Background:

  • Engine runs great but the throttle no longer engages the drive at all in forward or reverse (previously worked as expected did though with a clank I attributed to idle speed)
  • Shift cable mechanism looks good (cotter keys there, responds to throttle movements in both directions)
  • There is a “bell housing” at the back of the engine that meets at the transom so I cannot see the “coupler” I’ve read about
  • There is no noise, resistance, really any indication I’m trying to engage forward or reverse
  • Propeller doesn’t move at all on dry land, it isn’t a spun prop

Question 1 – I’ve read about the eccentric piston and making sure that is working but don’t really understand it. It looks like a (fixed) mechanical device that pushes a cone up/down. I’m not sure how to trouble shoot it. Steps for how to identify an issue here are appreciated. The fact that no noise is emanating from the stern drive is making me think this could be the issue.

Question 2 – if I blew the u-joint I wouldn’t it clank or otherwise make some noise? It doesn’t look like there is enough room for non-interference fit

Question 3 – could I pull back the drive bellow to see a spinning shaft to conclusively confine the issue to the upper gears (remove “coupler” from as potential source of problem)
 
npwiesne said:
1980 Bayliner Explorer
Volvo Penta AQ120B
270 Outdrive

I picked this boat up this summer and it has been a great teaching experience for my children on setting points, rebuilding carbs, impellers and the general joys of boat ownership. I also taught them to ski and when it was finally my turn to show them how it was done the boat lost power to the outdrive after pulling my up. Any thoughts or advice on how to narrow down the issue are greatly appreciated. I’ve scoured existing threads and come up with a few questions based on what I’ve read so far.

Background:

  • Engine runs great but the throttle no longer engages the drive at all in forward or reverse (previously worked as expected did though with a clank I attributed to idle speed)
  • Shift cable mechanism looks good (cotter keys there, responds to throttle movements in both directions)

    Which end??? under the rear cover on drive??
  • There is a “bell housing” at the back of the engine that meets at the transom so I cannot see the “coupler” I’ve read about

    No couplers that normally fail in 270 drive.
  • There is no noise, resistance, really any indication I’m trying to engage forward or reverse
  • Propeller doesn’t move at all on dry land, it isn’t a spun prop

Question 1 – I’ve read about the eccentric piston and making sure that is working but don’t really understand it. It looks like a (fixed) mechanical device that pushes a cone up/down. I’m not sure how to trouble shoot it. Steps for how to identify an issue here are appreciated. The fact that no noise is emanating from the stern drive is making me think this could be the issue.

Remove back cover and see that the "rocker" arm moves when shifting. If it moves, then there are internal issues with the drive that may or may not be within your abilities to fix. From this point forward, based on your questions, I'd get and use an OEM Volvo shop manual.

Question 2 – if I blew the u-joint I wouldn’t it clank or otherwise make some noise? It doesn’t look like there is enough room for non-interference fit

Yes it would clank

Question 3 – could I pull back the drive bellow to see a spinning shaft to conclusively confine the issue to the upper gears (remove “coupler” from as potential source of problem)


Not necessary...
Click to expand...

Cannot stress too strongly the need for an OEM shop manual for you if you are working on 200 series drives at all.
 
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npwiesne said:
1980 Bayliner Explorer
Volvo Penta AQ120B
270 Outdrive

I picked this boat up this summer and it has been a great teaching experience for my children on setting points, rebuilding carbs, impellers and the general joys of boat ownership. I also taught them to ski and when it was finally my turn to show them how it was done the boat lost power to the outdrive after pulling my up. Any thoughts or advice on how to narrow down the issue are greatly appreciated. I’ve scoured existing threads and come up with a few questions based on what I’ve read so far.

There is a vertical shaft spline coupler that joins the lower gear unit's vertical shaft to the transmission's vertical shaft.
This provides a shear point in the event that the prop undergoes an impact.
You can remove either the transmission or the lower gear unit to check this spline coupler.


Background:

  • Engine runs great but the throttle no longer engages the drive at all in forward or reverse (previously worked as expected did though with a clank I attributed to idle speed)
  • Shift cable mechanism looks good (cotter keys there, responds to throttle movements in both directions)
  • There is a “bell housing” That would be a Flywheel Cover at the back of the engine that meets at the transom so I cannot see the “coupler” I’ve read about
  • There is no noise, resistance, really any indication I’m trying to engage forward or reverse
  • Propeller doesn’t move at all on dry land, it isn’t a spun prop
You can also remove the eccentric piston housing, spin the prop shaft, and see if the bronze sliding sleeve is rotating.
Hold the sliding sleeve from spinning while you do this.
If it is rotating with some resistance against it, then the spline coupler is likely OK.
If it does not rotate, then it's likely that the spline coupler either sheared, or the vertical shaft sheared off.


Question 1 – I’ve read about the eccentric piston and making sure that is working but don’t really understand it. It looks like a (fixed) mechanical device that pushes a cone up/down.
Inside of this area is an eccentric piston that raises and lowers a shift shoe.
The shift shoe is what glides in a grove within the bronze sliding sleeve.
Occasionally a shift shoe will break.
Pull the eccentric piston housing and take a look.
It will cost you three new OEM O-rings only.... one dip stick O-ring, one drain plug O-ring and one eccentric piston housing O-ring.


I’m not sure how to trouble shoot it. Steps for how to identify an issue here are appreciated. The fact that no noise is emanating from the stern drive is making me think this could be the issue.

Question 2 – if I blew the u-joint I wouldn’t it clank or otherwise make some noise?
Depending on where it broke, it may.

It doesn’t look like there is enough room for non-interference fit
I'm not following you on that one!

Question 3 – could I pull back the drive bellow to see a spinning shaft to conclusively confine the issue to the upper gears (remove “coupler” from as potential source of problem)
As an alternative, you could turn the engine over while the eccentric piston housing is removed.
If all is in tact, the gears will spin..... but unless engaged, the sliding sleeve will not.

I would still start with the other items first.
Click to expand...

Since this occured while you were on the water, making it very unlikely, I'll mention it anyway:
Synthetic gear oil can create too much lubrication that will prevent the necessary friction that causes the sliding sleeve to lock up into the corresponding gear cup.
Your drive requires 30W engine oil...... not heavy gear oil, nor synthetic oil without some additional work to the sleeve and gear cups.



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Capt Bob and Ricardo,

Answers to a few of your questions before getting into what I did / learned.

I changed the out drive oil and o-rings when I got the boat. I'm not sure what was in it before, something green/blue that didn’t look like motor oil, but I used motor oil, 30W.

When i indicate the shifter cable was working I meant under the "270 Cover" on the out-drive. Moving the throttle forward/backward moves the cable, shift piston, reverse lock pawl... I think everything is working fine there.

Here is what I did

  • I disconnected the cotter pins to separate the shifter cable from the outside of the eccentric piston and manually shifted the boat into gear. I was able to spin the prop in one direction but not the other; the opposite occurred when I manually moved the piston to the other direction. This made me think I "fixed" it simply by freeing the piston.


  • I removed the eccentric piston and looked around. No apparent damage to shoe, upper/lower gear, metal filings, or anything to indicate an issue there.


  • With eccentric piston removed I spun the prop while holding the brass cone and wasn't able to stop the cone from spinning. Furthermore, if I manually pushed the cone up/down if would engage the gear and prevent me from spinning the prop. I don't think I sheared the shaft of the coupling.



  • I "bunted" the engine with the piston removed but didn't see the upper or lower gear advance. This made my heart sink a little. I think the u-joint is gone.


  • I buckled it all back up to test it reassembled hoping that somehow it worked. I started the engine, inadvertently with it up, and when tilting the motor down it made some horrible clanking noise, I think this is the u-joint banging around.

If you have any other thoughts / ideas to get to the root cause I’m all ears. If not, I’ll review some manuals, order parts, and cross my fingers. If there is “how to” thread or video your aware of that compliments that manual by all means point me toward it.

Thanks,
Nathaniel
 
With the gear oil drained, remove the helmet pin and lift the helmet up and out of your way.
Remove the clevis pin from the vertical linkage shaft where it connects to the eccentric piston.
Remove the two cap screws and the two nuts that secure the transmission to the intermediate housing.
Loosen the AFT bellows band clamp.
Lift the transmission up and turn it 90° sideways, and pull it straight out.

Now you will be able to view the universal drive shaft!

I very likely have a new universal drive shaft that I could sell to you if interested.



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Ricardo,

Thanks for all the advice. I was able to remove the stern drive and the u-joint. The middle connector yoke snapped off an ear but each mating ends to the enging and upper gear box are in good shape. Please let me know if you have a spare as they seem to quite hard to locate.

Nathaniel
 
Yes, I do have a brand new unit. (I sent a PM to you)


As for the center section and the male and female yokes, if the any one of the bearing cap bosses have broken, there is a good chance that the other components have become twisted from what ever it was that caused the damage.
Your best bet would be to replace the entire universal drive shaft.

Or.... if you're feeling lucky, you could try replacing the center section only, of which I also have.

Let me know what you'd like to do.


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