Alpha onr Gen 2 Replacement

[helimech2003]

Hello all. I have a 94 Chaparral with the 4.3lx and a alpha 1 gen 2. Long story short, I traded for the boat and the guy was a "boat mechanic". Well he messed around in the out drive for whatever reason and now its making ALOT of metal so, time to replace it. I was looking in the local craigslist and found a gen 2 outdrive for a $1000. Problem is, it's for a 5.0L. Not sure of the gear ratio yet so, my question is....If it's the 1.62 ratio will it work in place of my 1.84 ratio or should I just go with a complete SEI unit?
Thanks for the help

 

[Mad Props]

Some people run different ratios and change props to compensate but its not a recommended practice. You really want to try and find the correct gear ratio.

Do you know what the issue is with your current drive and what makes you think it can't be fixed?

 

[Scott06]

Unless the 5.0 was in such a heavy boat that it used a 1.84 drive it will be a 1.62. You’d have to go down in pitch to make it work so probably best to just get right ratio. Typically see a bunch on eBay if u haven’t looked there.

FWIW when I repowered my boat I went the other way 4.3 drive ratio with a 5.0 going back in. It worked but had to step up from 19” to a 21” prop.

 

[helimech2003]

Some people run different ratios and change props to compensate but its not a recommended practice. You really want to try and find the correct gear ratio.

Do you know what the issue is with your current drive and what makes you think it can't be fixed?

Well it's not done yet but when you turn the prop it sounds like the bearings are dry and full of sand. I pulled the drain plug and the amount of metal on the magnet was the size of the drain hole. No big chunks but a lot of flakes. I drained some of the oil out and it was full of metal flake. I know someone has messed with it because when I had it out to do the bellows and gimbal bearing it had hammer marks on the input flange nut. When you turned the driveshaft you could feel the bearings "rachet" like they had been over torqued.
I figured it was just a matter of time

 

[Scott06]

Might be better off having a competent mechanic diagnose before throwing in the towel, or at least pull the top cap off and
see
whats going on

 

[Mad Props]

Agree with Scott. Plus if you can diagnose if the problem is limited to the upper or lower, you might be able to get away with only buying one or the other and save some money.

There honestly isn't much going on inside these units so they are very repairable, however, the components can get pretty pricey depending on the issue to the point where it doesn't make sense to fix.

 

[achris]

Sounds quite bad, bad enough to contemplate just replacing the entire drive...
As for the 1.62 ratio drive... The later 4.3s were supplied with that ratio, so nothing bad there. But as has been pointed out, you'll need to re-prop. There's a 12% difference, so if you currently run, for example, a 21", you'll need to knock it down to a 19"...

Chris.......

 

[Bondo]

Ayuh,..... I agree,.... If it's makin' metal, a rebuild tab will probably exceed the replacement cost,....

I've run both the 1.65, 'n the 1.84 on my 21' tinbarge with a 4.3LX,......

The 1.65 was happy at 19" of prop, 'n the 1.84 is happy with a 21" wheel,.....

 

[helimech2003]

Ok. Just found out it is a 1.62. Next question is. Mines a 94. The replacement is a 2006. Are they interchangeable? They are both gen 2

 

[achris]

Ok. Just found out it is a 1.62. Next question is. Mines a 94. The replacement is a 2006. Are they interchangeable? They are both gen 2

Yes....

 

[thumpar]

Agree with Scott. Plus if you can diagnose if the problem is limited to the upper or lower, you might be able to get away with only buying one or the other and save some money.

There honestly isn't much going on inside these units so they are very repairable, however, the components can get pretty pricey depending on the issue to the point where it doesn't make sense to fix.

The issue with that is even if the obvious problem is only at the upper or lower it has all been run with the same lube full of metal.

Sounds like you have it figured out with the 1.62 ratio. That is close enough you can reprop.

 

[helimech2003]

Thank you guys so much for the replies. I’m going to go look at it today and see if it’s good. On the plus side if I buy the outdrive it comes with everything else. The guy pulled the entire power package and is converting to outboard. Down side. Engine has a cracked block.

 

[nola mike]

Don't know that that's much of a deal for a drive with an unknown history, though don't know your local market. You can get them for <$300 all day around here. Maybe a bit more scarce in June...

 

[thumpar]

Take it all. You may be able to sell off the parts and break even or close to it. Even with a cracked block it has everything needed to convert a truck motor into a marine motor for someone.