Gearbox woes? Quick help needed!

[BigStu]

After a delay my ‘new’ Longbow is meant to go in the water tomorrow first thing for our hols.

However…. When I was reattaching the prop shaft to the clamp on the gearbox (after a stern gland service) I noticed in either gear the shaft could still turn in both directions (see other post) . In all the other boats I have had this should engage the engine and ‘lock’ the shaft (unless you can turn the engine). The engine is a Volvo Penta MD2030D with an MS2 Gearbox

I was surprised at this so had no choice but to have to run the engine up and see if she would turn the prop in Gear with the engine running. I know normally this would not be an ideal thing to do on the hard but I wanted to see what would happen. So only momentarily put her in gear.

Basically in either forward or reverse when ‘clicked’ into gear nothing happens. It then takes probably about half speed on the engine to make the prop turn. That would mean to creep forward you need about 2000 revs! If I power back down and leave in gear to the ‘notch’ it spins but I can easily stop the shaft with my hand. Also if I leave in gear and turn the engine off- I can turn the propellor with not a lot of effort the way it should be ‘locked’.

My feeling is this gearbox is shot as all of that in theory should not happen (I think). The cables are pushing the leaver all the way forward so it seems set up right. is this the classic worn clutch or cones symptoms?

The last thing I want is to drop her in and have a load hassle with the gearbox when I should be having a stress free holiday!!

I’ve got to make a call today whether to go ahead and get her in- but this sounds like trouble to me….

 

[ean_p]

Not familiar in any way but have a look here for some pointers.....https://forums.ybw.com/index.php?threads/help-with-penta-ms2-gearbox.342636/

 

[Boater Sam]

Shear pin?

 

[VicS]

After a delay my ‘new’ Longbow is meant to go in the water tomorrow first thing for our hols.
However…. When I was reattaching the prop shaft to the clamp on the gearbox (after a stern gland service) I noticed in either gear the shaft could still turn in both directions (see other post) . In all the other boats I have had this should engage the engine and ‘lock’ the shaft (unless you can turn the engine). The engine is a Volvo Penta MD2030D with an MS2 Gearbox
I was surprised at this so had no choice but to have to run the engine up and see if she would turn the prop in Gear with the engine running. I know normally this would not be an ideal thing to do on the hard but I wanted to see what would happen. So only momentarily put her in gear.
Basically in either forward or reverse when ‘clicked’ into gear nothing happens. It then takes probably about half speed on the engine to make the prop turn. That would mean to creep forward you need about 2000 revs! If I power back down and leave in gear to the ‘notch’ it spins but I can easily stop the shaft with my hand. Also if I leave in gear and turn the engine off- I can turn the propellor with not a lot of effort the way it should be ‘locked’.
My feeling is this gearbox is shot as all of that in theory should not happen (I think). The cables are pushing the leaver all the way forward so it seems set up right. is this the classic worn clutch or cones symptoms?
The last thing I want is to drop her in and have a load hassle with the gearbox when I should be having a stress free holiday!!
I’ve got to make a call today whether to go ahead and get her in- but this sounds like trouble to me….

You have already checked that the remote lever moves the lever on the gear box .... but is it moving it fully?

Disconnect the cable at the gear box and try moving the gearbox lever by hand. If still no joy it must be a gearbox problem .......... cone clutches not engaging , but unexpected that both forward and reverse should both fail.

Maybe worth taking look at the selector mechanism
( I have the workshop manual down loaded... if I can find a link to it I will post it)

 

[chewbacca]

Has any work been carried out on the gearbox? I only ask as the setup for the gear selector is important. The correct number of shims is important or you won't get selection . It's easy to misplace one without realising you've lost one. If it has not been apart then this won't apply. The dog also has to be located in the correct orientation again if the gear selector mechanism hasn't been out obviously this doesn't apply.

 

[VicS]

( I have the workshop manual down loaded... if I can find a link to it I will post it)

It's here VOLVO PENTA MS2 WORKSHOP MANUAL Pdf Download
Down load it .. It'll be easier to read

 

[VicS]

Shear pin?

where is this shear pin?

.

 

[chewbacca]

I agree with VicS more likely to be selector related than gearbox

 

[VicS]

Not familiar in any way but have a look here for some pointers.....https://forums.ybw.com/index.php?threads/help-with-penta-ms2-gearbox.342636/

Link is
Help With Penta MS2 Gearbox

.

 

[BigStu]

It’s a new boat so no idea if work has been carried out. I’ve done two solid weeks work on her to get her ready for the hols and do all the items the surveyor picked up to be in this position the night before she goes in…. I feel like just selling her and moving on. Very P’ed off. It’s very tidal where she goes in so can’t chance a problem or I’ll be on my side in the mud!

 

[John_P]

Have you checked the oil level, also does it have the correct oil spec for the gearbox, when was it last changed, if its unknown to you it would be worth changing the oil for some fresh before you condem the box.

 

[BigStu]

Oil level looks fine and oil is clean. Don’t know what spec the oil is but I think I’m screwed getting whatever it is on a Sunday night!

 

[Major_Clanger]

Can you post a couple of pics of the box and coupling? Don't despair, it could be a simple fix.

 

[Seastoke]

Did it work before you took out shaft.

 

[scottie]

The cone in this box is on a spiral shaft so without the engine running you should be able to lock the box in drive by putting the box in gear and turning the propeller one way (trial and error) then by doing the same in other gear and opposite rotation lock ing again
it is a common problem that the control neutral run up can stick but you would see that the selector is not moving but check with cable disconnected and ensuring the lever is fully engaged it will not normally fully engage without rotation
the selector is a wedge in a V shaped groove this has the result that it ensures the clutch fully engages and dis engages in practice this means it is more likely to engage than find neutral if worn due to the spiral wanting to move the central shaft

 

[scottie]

PS is the shaft coupling fastened?

 

[mattonthesea]

We had a similar problem a few years ago in L'Orient. Engine not used much in ten years before I bought her. Turned out to be the damper (sort of rubber shock absorber for the shaft) had perished. Didn't see it until I'd taken the gearbox off.

 

[BigStu]

Here is a video

of what is going on. You can see when I put in reverse it just starts to spin at high revs (I then back off as boat is out of the water). It basically only starts to spin at high revs in either direction. Access is a real pain to disconnect cable- but I’m sure the selector is fully forward/reverse.

 

[Major_Clanger]

Remove the gearbox cable and try moving the lever manually.

 

[scottie]

once again have you definitely confirmed that the shaft is not turning in the coupling as that is exactly what would happen
tighen up the coupling bolts and check for missing drive pin and or locking screw