Leg Trouble AGAIN!

[MedDreamer]

Earlier in the year I posted about the failure of my outdrive and possible causes. (My boat is a 2001 Bayliner 2855 with 5.7L mercruiser (rated 250hp) and Alpha 1 drive). The top half of the drive had completely eaten itself. and has been replaced by a professional workshop not unfamiliar with these parts.

This last weekend we had perfect weather in the Med (sorry to those of you who are now lifted or thinking about winterising ) and we were out in Alcudia bay cruising around 18 knots (bottom dirty so this was about 3700 revs) and after about 15 minutes it happened again! (8 hours run since replacement!!). I would have thought that even if I had been running flat out for 15 minutes I would not have been straining any part to breaking point.

I know that the 5.7L and Alpha Gen 2 leg are a pretty standard combination so there should be no incompatibility problem there. I am also aware that this is not a "high performance" combination for my boat but as we are more concerned with comfort than outright speed then this has not been a problem.

One other point that may be relevant. Up until this last weekend the leg trim switch
has not been working (work outstanding from the original repair) so I have not been able to trim the leg. The switch was fixed earlier this month and this weekend is the first time I have been able to trim the leg. That said I didn't trim much (hardly registered on the trim gauge). But could it be just a co-incidence that it fails the first time the trim works?


As I really want to get to the bottom of this I would be grateful for any opinions or shared experience.

Thanks

Martyn


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[ccscott49]

I dont know whats wrong, but I'd have a word with Alex and Pete, (balyn marine??) in the marina, if you havent already.

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[danielbroad]

Had an alpha one drive leg on my old Bayliner without significant problems, its a proven piece of kit even though its not as durable as the Bravo or Volvo legs.

My guess would be you've got a bad seal which is letting water in / oil out of the leg somewhere - have you got the external oil reservoir? Was the level OK?

Try also asking this question on the and <A target="_blank" HREF=http://www.boatered.com>Boatered.com where many Mercruiser experts hang out.

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[davedpc]

Were the replacement parts genuine Merc. parts? Was the shimming done correctly? Was the oil passage unobstructed from the bottom of the leg to the top bevel set? Was the unit low on oil cuz the top set will break up without lube. after only a few minutes. Best go to a Merc. dealer this time. Dave.

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[Nat]

Sounds like something important has been overlooked to me. I'd be on the dealer who repaired it. If it was fitted & shimmed correctly & oilways clear this should not happen. I've just had a new gear set fitted in my OMC leg & touch wood its fine 25 hrs so far on it. I dont want to point fingers but sounds to me whoever fitted it should be sorting it............Nat

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[MedDreamer]

To be fair they are Nat with no quibbles. Just don't want it to happen again.

Martyn

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[martynwhiteley]

Sorry to hear about the troubles again Martyn.

Beginning to be grateful I've now got a Bravo 2, even if a new prop will cost me £500!

Hopefully it's not contageous if your still on for the 6th!



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[shetland]

Was the leg presure tested after the completion of the work.

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[MedDreamer]

Pardon my ignorance, but what is leg pressure and how is it measured.

Martyn

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[MedDreamer]

Hi Martyn

The thing is the Alpha drive is supposed to be the least complicated one!

You had an Alpha drive on your Birchwood didn't you after your "conversion"?
What did you have to be aware of when fitting it? Can resistance in the lower leg cause the upper section to break without damaging the lower section (which appears undamaged). My PETROL engine presumably has less torque than your diesel had but you didn't have any problems, the engine seems to be running as smooth as a nut so that doesn't seem to be the problem so what the bloody hell caused it? I haven't hit anything or wrapped anything around the prop, I'm worried that we haven't got the root cause of the failure and it may happen again.

Yup still on for the 6th, I'll ring you next week to sort out.

Regards

Martyn






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[martynwhiteley]

The biggest two issues that are stressed during installation are:-

1) Proper engine/leg alignment (and I guess if this was out, it would cause the upper part to fail first. Also, perhaps leg trim could have an effect here, since any misalignment would become more of a problem as the leg is trimed away from the centre position).

2) Refilling the oil from the lower drain plug, ensuring the leg is fully down during the process and the vent screw open. (certainly if there was an air lock, the oil would not be properly covering the upper drive parts with obvious consequences).

Cheers,

Martyn

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[MedDreamer]

I've PM'ed you

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[Nat]

Hope it all works out for you. Nothing worse than breaking down at sea.
.....Wish you well..............Nat

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[Freebee]

If you know what numbers of teeth you have on your gears and can tell me I could check with the two secondhand spare sets I have, you are welcome to one of those.

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[MedDreamer]

Thanks Mike thats very kind of you but it is being replaced by Mercury.

Martyn

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