Help ! Python unit broken!

[stuart]

Disaster struck this weekend when I noticed that there was a lot of vibration on the prop, on inspection the python unit that was fitted 18months ago has broken!

 

 

The thrust bearing "B" has seperated from the thrust housing "A" as shown on this picture. I'd love to know the forces involved in this as nothing appears to be broken or cracked.

 

Obviously this leaves the boat without drive, luckly its back on its home mooring.

 

The other problem, as the unit failed under power, the parts H and F (CV joint) have smashed into each other and damaged the faces. It appears only superficial damage, nothings split.

 

I've spent a couple of hours trying to remove the unit from the boat but just cannot get the prop shaft clamp off!

 

 

 

 

Theres a ring of allen bolts which have been removed. The instruction manual (http://www.albatross-marine.co.uk/_pdf/Installation%20Manual.pdf) says to use M8 bolts to screw into the clamp to pull it off the prop shaft - buts its just not moving.

 

Any ideas on how I can get this off? The prop shaft is free to rotate and slides fore/aft about 6" so cannot get any grip/fix on it!

 

I'll speak to Albatross Marine on Monday where the unit was purchased - hopefully this is a warranty repair if I can get the unit back to them!!

Edited December 16, 2007 by stuart

[MoominPapa]

Disaster struck this weekend when I noticed that there was a lot of vibration on the prop, on inspection the python unit that was fitted 18months ago has broken!

 

The thrust bearing "B" has seperated from the thrust housing "A" as shown on this picture. I'd love to know the forces involved in this as nothing appears to be broken or cracked.

 

I wonder if the bearing housing has been fitted backwards? The cross-section seems to show a shoulder in the housing casting on the left of the bearing. That would stop the bearing moving to the left and take the axial thrust when going forwards. Presumably there's a circlip or similar to retain the bearing as stop if moving rightwards when going astern.

 

Your picture seems to show the bearing has come out of the housing rightwards so maybe it's been fitted the other way around, with the shoulder taking astern thrust and whatever retains the bearing post-installation taking the forward thrust. Is there a broken circlip hiding in that bilge-water?

[John Orentas]

That ring of 12 holes that can be seen, I suspect that one or two of the M8 bolts should be screwed into one or more of those holes then tightened acting as a sort of extractor.. This kind of thing is common with bearings.

 

I assume you have removed nuts and bolts 'c' along with the soft spacers etc.

Edited December 16, 2007 by John Orentas

[magnetman]

You could attempt to jam the propeller against the skeg using a bit of wood to stop the tailshaft rotating.

[Guest]

I may be talking through my backside, and if so will shut up, but: I think your sterngear, like mine, is a Vetus with a neoprene cutlass? Is it correct to use this type of shaft, which flexes in the tube, with a Python or similar? Just a thought.

[stuart]

I may be talking through my backside, and if so will shut up, but: I think your sterngear, like mine, is a Vetus with a neoprene cutlass? Is it correct to use this type of shaft, which flexes in the tube, with a Python or similar? Just a thought.

I do have the vetus sterngear. The python people said it would be fine, however I do share your thoughts - is there too much movement?After the gearbox splitting from the engine (causing the python to be fitted in the first place!) I'm going off this stuff rapidly!

Your picture seems to show the bearing has come out of the housing rightwards so maybe it's been fitted the other way around, with the shoulder taking astern thrust and whatever retains the bearing post-installation taking the forward thrust. Is there a broken circlip hiding in that bilge-water?

Thats what I was wondering, however it's supplied from factory fitted like in the diagram and every picture you see has it the way it was fitted.Theres no easy way to get the bearing back into the housing either - not without extreme force.I've not seen any missing clips and the bearing itself it still solidly attached to the other half.

I assume you have removed nuts and bolts 'c' along with the soft spacers etc.

Correct !Being as this is my first and only boat, that has this vetus stuff installed - with "normal" stern gear I'm assuming that the prop is fixed in a solidly mounted tube (which has packing/stuffing inside) and hence doesn't move left/right at all? The current one can easily move 1-2" in the horizontal/vertical planes.

[Guest]

I do have the vetus sterngear. The python people said it would be fine, however I do share your thoughts - is there too much movement?

 

After the gearbox splitting from the engine (causing the python to be fitted in the first place!) I'm going off this stuff rapidly!

What engine is it Stuart? Mine is the Vetus 415 with the 'orrible techodrive box. The Vetus dealer who fitted ours used an R&D nylon coupling which allow a certain amount of movement. I can't help that think your setup with the neoprene will allow the lower end of the shaft and prop to behave like a pendulum, and put side forces on the top bearing in the Python. There again you would expect the makers to be aware of any shortcomings in this sytem. Was your gearbox just connected directly to the shaft when the gearbox failed? These type of shafts have been common on seaboats, but often with longer shafts.

[stuart]

Was your gearbox just connected directly to the shaft when the gearbox failed?

 

These type of shafts have been common on seaboats, but often with longer shafts.

 

Isuzu 35 and PRM120D2 - fitted directly to the prop shaft. Liv. Boats standard.

 

The original fitting (with no flex) needs almost perfect engine lineup which didnt seem to be the case. Fixed under HMI warranty as it was the bolts between engine + gear box that failed.

 

 

Anyone care to take a guess on how much to reverse fit a "normal" stern tube + greaser?

[Guest]

Isuzu 35 and PRM120D2 - fitted directly to the prop shaft. Liv. Boats standard.

 

The original fitting (with no flex) needs almost perfect engine lineup which didnt seem to be the case. Fixed under HMI warranty as it was the bolts between engine + gear box that failed.

Anyone care to take a guess on how much to reverse fit a "normal" stern tube + greaser?

 

This is my setup

 

 

This is what the Vetus looks like inside.

 

I wonder if it would be possible to fit conventional bearings in the tube, and fit a stuffing box/greaser? Should be cheaper than renewing the lot?

[stuart]

This is my setup

 

This is what the Vetus looks like inside.

 

I wonder if it would be possible to fit conventional bearings in the tube, and fit a stuffing box/greaser? Should be cheaper than renewing the lot?

 

Mine looks very similar (except for the python!) - not sure about fitting bearings inside the existing tube - perhaps this is not a problem at all - might just be faulty python. Now if only I can find that damn receipt!

[Guest]

Mine looks very similar (except for the python!) - not sure about fitting bearings inside the existing tube - perhaps this is not a problem at all - might just be faulty python. Now if only I can find that damn receipt!

Did you pay with plastic? That is usually as good as the receipt.

I seem to remember that the Python has a long warranty period?

Edited December 16, 2007 by Guest

[stuart]

Did you pay with plastic? That is usually as good as the receipt.

I seem to remember that the Python has a long warranty period?

 

Yes it would be on a card (now if only I can find my card statements!) - I think the python warranty is 5yrs (might even be 10).

 

Assuming this failure is covered under warranty!

 

 

I've got every receipt for the boat (even 99p for a bag of screws!) but can never find the one you want....

Edited December 16, 2007 by stuart

[Guest]

Yes it would be on a card (now if only I can find my card statements!) - I think the python warranty is 5yrs (might even be 10).

 

Assuming this failure is covered under warranty!

I've got every receipt for the boat (even 99p for a bag of screws!) but can never find the one you want....

I think you can get a copy of any statements from your card company. Woud it be worth speaking directly to the manufactures in this instance and email the image?

[stuart]

Spoken to Albatross marine and they are happy to take a look under warranty, however I cannot get the damn thing off the prop shaft!

 

I've removed the retaining ring (the one with 12 holes in it) and the female version of this but the whole unit is stuck fast, must have surface rust must be holding the thing fast to the prop.

 

Help !! Any ideas ?!?

[steelaway]

Spoken to Albatross marine and they are happy to take a look under warranty, however I cannot get the damn thing off the prop shaft!

 

I've removed the retaining ring (the one with 12 holes in it) and the female version of this but the whole unit is stuck fast, must have surface rust must be holding the thing fast to the prop.

 

Help !! Any ideas ?!?

 

Hi there

If it has taken this much power to smash the coupling, the whole lot could have spun on the shaft. Stainless is notorious for tearing and could have welded itself onto the shaft. Nightmare!!

[Narrowjack]

Hi there

If it has taken this much power to smash the coupling, the whole lot could have spun on the shaft. Stainless is notorious for tearing and could have welded itself onto the shaft. Nightmare!!

Not sure if you've got the clamp ring released by now? Probably, as you posted some time ago. The way to get the taper rings to seperate is to use the two 8mm bolt holes to screw in a couple of long bolts with a weight on them which is free to slide up & down the bolt. You then use the sliding weight as a 'hammer' under the bolt head to get the assembly to release. Believe it or not these are termed 'slide-hammers'. Sorry to see that you've had this problem. Especially as I've just fitted one of these units to an identical set up as yours! Appreciate if you'd let me know the outcome of the failure investigation. Good luck.

[blackrose]

This is my setup

 

 

This is what the Vetus looks like inside.

 

Mine is the same - the coupling goes straight onto the propshaft without any flexidrive and the propshaft goes out through the vetus water lubed sterngland. What does the Python unit do exactly?

 

Off topic, but that cutaway of the sterngland shows water passing from the weedhatch tube through the stengland. When I talked to Vetus at one of the shows last year they told me it went the other way around - it was sucked in through the sterngland and any excess was pushed out through the tube connected to the weedhatch.

[AndyM]

Off topic, but that cutaway of the sterngland shows water passing from the weedhatch tube through the stengland. When I talked to Vetus at one of the shows last year they told me it went the other way around - it was sucked in through the sterngland and any excess was pushed out through the tube connected to the weedhatch.

 

I can vouch for that - I took what I thought was the "feed" tube off, just above the stop cock and found water pouring in from the stop cock. this was a bit of a shock as I was led to believe that the prop shaft was cooled from water from the weed hatch - obviously the other way around!

 

Andy.

[Phoenix_V]

Spoken to Albatross marine and they are happy to take a look under warranty, however I cannot get the damn thing off the prop shaft!

 

I've removed the retaining ring (the one with 12 holes in it) and the female version of this but the whole unit is stuck fast, must have surface rust must be holding the thing fast to the prop.

 

Help !! Any ideas ?!?

 

 

Came acros this when browsing old topics, would love to know what the eventual cause was and how helpful Albatross were

[Gary Peacock]

Came acros this when browsing old topics, would love to know what the eventual cause was and how helpful Albatross were

 

Albatross are no more!

 

Ceased trading a while ago.