5.0L cracked upper housing

[welbo97]

I bought an old boat. Thought, "Hey, I can fix stuff". I've learned a lot in a few days about how much I didn't know.

It's a 5.0L Alpha I Gen II, s/n: OF417955, drive s/n: OF499009. I drained and replaced the gear oil as part of my after purchase maintenance". The old oil was dark but not in too bad shape. On the first outing I noticed the reservoir oil was getting "milky". So I pulled the outdrive off, drained it and pressure tested it. I found a crack in the upper housing, driveshaft bearing housing. Either I did something that caused myself to crack that or it was just about to/just had cracked and hadn't gotten any water into the outdrive yet. The gear under the top cover looks perfect.

So now I'm trying to decide if I should buy a complete upper or just a housing and put my gearset into it. I already have a spanner and seal kit on the way. Will I have to reshim the gears in the new housing? Is it likely the shims out of the old housing will work and a measurement will confirm? There's a pretty big price difference between a complete upper and a housing. Plus finding a 1.65R ratio that's in good shape may be tough.

Maybe buy a housing and find a merc mech that can assemble it? Is there a list somewhere? Know anyone near San Antonio, TX?

On a side note, I really like that engine. 190hp out of a 5.0L seems like it's just loafing. The tag says 4600rpm WOT but it'll do a lot more than that based on the throttle position. Maybe i need a higher pitch prop. Topic for another day.

 

[Scott Danforth]

first, welcome aboard

post a few more times, then post some pics

depending where the cracks are, you may be able to have them repaired (welded).

 

[achris]

If you buy just the housing, yes you'll need to re-shim it. The shimming is to allow for differences in each individual casting. Unless it can be welded (after which I would check the shimming anyway), your best option might be an SEI upper housing. They're not too expensive, and you'll get the ratio your looking for.

Chris ..

 

[welbo97]

first, welcome aboard

post a few more times, then post some pics

depending where the cracks are, you may be able to have them repaired (welded).

Thanks for the responses. In doing searches, this forum came up many times with what appeared to be well thought out, very courteous responses to technical questions. It was easily the first place I wanted to sign up.

The crack is in the input shaft bearing housing. It runs the full length of that bearing housing. A used housing is only about $200 on ebay. The SEI new units look like they are running about $800. I think I'll go ahead and disassemble my cracked upper and see how the internal parts look. Maybe I can figure out why this housing cracked. If the bearing seized and the shaft is scrored, it'll be an easier decision. Of course, $800 gets me back on the water faster. I've had the boat for a week, been out 5 days. I'm not sure the kids will wait for my to patiently rebuild the old one. I could have a brand new SEI by Tuesday! They have a better warranty than my personal rebuilds too.

The SEI116 comes in a 1.62 ratio and says it replaces the 1.65 ratio of the Brunswick OEM. Does that mean it won't have 24:24 teeth drive/driven gears in the upper?

 

[Searay205]

that drive is a dime a dozen. Look on Craigslist i see them all the time both halves for $600. I think SEI is hit and miss, some have luck with them others don't. Upper pretty easy to disassemble. truth be told i sold one two years ago $200 for whole outdrive. Mercruiser. wanted rid of it.

My guess you cracked it during pressure test. more than 15 psig and you have a grenade on your hands, its not a pressure vessel just cast aluminum.

 

[Rick Stephens]

I don't think you could crack the housing around the bearing pak with pressure, it would blow out somewhere else first. That's the beefiest part of the upper case. Maybe a bad u-joint could cause that.

The gear set of the 1.62 SEI is 24/24.

 

[welbo97]

The forward bearing on the driveshaft input shaft is cracked and spun in the housing. Looks like it ran dry. I can take the blame for that. I didn't properly service the gear oil when I refilled it. So a new SEI unit it is. That'll be $800 in stupid tax, please.

Searay205, that was a good idea to look on Craigslist. I hadn't thought of that. Unfortunately there wasn't anything available anywhere around here.

The gearset still looks good. Maybe I'll sleep with it under my mattress for a while to remind myself to RTFM before attempting to do maintenance again.

Thanks for the advice, all. Next post will be more fun, hopefully.

 

[achris]

...The SEI116 comes in a 1.62 ratio and says it replaces the 1.65 ratio of the Brunswick OEM. Does that mean it won't have 24:24 teeth drive/driven gears in the upper?

The difference between 1.62 and 1.65 is in the lower housing. The upper housing will still be 24:24, so with your lower housing 17:28 gears, it will remain at 1.65.

Chris.....

 

[Rick Stephens]

Check carefully that there are no metal shavings in the lower before assuming it is clean.