Mercruiser Bravo 2 steering arm....rusted

[jointventureII]

Went to have a look at a boat I am interested in recently.

I am not all that familiar with outdrive setups - I've had Alphas before but many years ago.

The boat is going very cheap as it needs a fair bit of work (mostly aesthetic) but I would have to pull the leg off anyway, which isn't a problem. Engine & leg are 2007, boat is kept in the water, last service March 2020. Picture of the problem below.

On the sea trial there was no play in the steering at all. What I'm concerned about is the things I can't really see. Anyone with experience of these drives know what other problems there could be concealed, given the state of that steering arm?

 

[simonfraser]

On a Volvo leg there is a bearing at the top
if that is not greased regularly it corrodes and starts to leak

 

[spannerman]

I have seen many Mercruiser transoms with rust in this area. Its caused by seawater leaking past the steering shaft. Look with a good light to see if its wet in the recess where the arm comes through the transom, also look further down for telltale salts stains. If you catch them early you can replace the seal. I have done a lot of these and don’t use the original seal which has the lips facing inwards? I use a double lipped seal and drill and fit a grease nipple on the outside like there used to be years ago. In the worst case the aluminium where the seal sits is corroded away so there is nothing to hold a new seal, which then means a new transom assembly. Its a big job either way with engine out then transom out and strip down to see if the steering shaft can be reused, they are the first couple of parts to be assembled in the whole transom shield. I did my own boat 10 years ago and machined the shaft and fitted a stainless sleeve and its never leaked since with a shot of grease once a year. I repair 3/4 of these each year as its a known weakness with the hard plastic seal they use installed the wrong way allowing water past the lips.

 

[jointventureII]

Spannerman thanks a lot that's cracking info. The recess seemed dry when I had a look, however the quantity of rust on the arm was worrying i.e. this has been going on a while. The engine air intakes are more or less directly above and facing forward - I did a sea trial in a F4-5 and 3ft short sharp chop (it's only a 25ft boat) and gave it a decent work out but of course plenty of spray would have ended up down the intakes - whether this is the cause of the rusted bolts on the transom assembly though, I wouldn't know.

Having had a good look at parts prices, it seems a 2nd hand transom assembly can be found for £500 or so, assuming the worst case scenario. Pulling the engine would be on the winter 2020-21 task list.

 

[Daibhheid1]

That could also be the result of a leaking bellows in which case I'd recommend getting a torch and a mirror to scrutinize under the engine for signs of salt water corrosion. That can cost on starter motors, alternators, even oil pressure senders and can make getting the engine out "challenging".

 

[jointventureII]

Thanks Daibheid. To be honest there was some light corrosion under the engine, though the alternator and starter motor seemed in good condition and unaffected.

The debate I'm having with myself is, whether I could keep / use the boat as it is OR if it needs attention right away.

I wouldn't be able to lift it out and dedicate a solid 3 months work on the hard until next winter (engine out, sort the bilge out and strip the engine / paint, sort the sterndrive out etc). It'd live in the water until then and get approx 20 hours use, short trips. Thus, if it's feasible to just live with it and, for example, connect an anode to the transom assembly (it might already be too far gone but it's worth a shot) whilst managing the rest of the system delicately (rust growth etc)

 

[oldgit]

Had and very old Regal 25 with pair of Mercruiser outdrives.
Water weeping past one the steering seals had soaked into the plywood core of the transom and left a mushy mess.
Definately worth sorting as soon as is spotted.

 

[jointventureII]

Cheers OG - good point

I've decided that if I can buy it, keep it on the hard until works are done (let's say 3 months all in) then take my time over it as I'm sure I'll find more surprises / parts that need ordering / Italian punctuality / lockdowns delaying the process

 

[B58]

Spannerman thanks a lot that's cracking info. The recess seemed dry when I had a look, however the quantity of rust on the arm was worrying i.e. this has been going on a while. The engine air intakes are more or less directly above and facing forward - I did a sea trial in a F4-5 and 3ft short sharp chop (it's only a 25ft boat) and gave it a decent work out but of course plenty of spray would have ended up down the intakes - whether this is the cause of the rusted bolts on the transom assembly though, I wouldn't know.

Having had a good look at parts prices, it seems a 2nd hand transom assembly can be found for £500 or so, assuming the worst case scenario. Pulling the engine would be on the winter 2020-21 task list.

Lok out for the same failure on the second hand transom you need to double check any signs of water ingress thats been painted over, the steering arm swivel pin can wear causing excessive steering, check it with the drive on and the steering ram connected then move from side to side.

 

[jointventureII]

B58 thanks - I've more or less factored in the price of a new unit, something in the region of £2.5k, and knocked this off the asking price. In any case I'd want to take spannerman's modification as it is a great idea.