Gears in upper unit destroyed ...

[Jason 641]

1985 Mercruiser 260...

I just recently replaced all of the seals, water pump, etc... in my outdrive. all of the gears and bearings looked great. Got everything cleaned up and re-assembled per the factory manual and it was all working good.... Until this Saturday.

I had spent most of the morning pulling people on the wakeboard so it was a lot of stop and go. Later in the afternoon we took a cruise down the lake (probably about 1.5 hours cruising around 3000 rpm's) and I heard a couple "pops" and the boat quit moving. Today I finally took the drive apart and found the gears in the upper unit completely destroyed, and it also ate up the inside of the gear housing pretty good in a couple spots. I attached a couple pictures for reference.

What do you all think? Can I replace the gears/bearings/races and be OK or should I get a whole new upper unit? What might have caused this, maybe broke a tooth on a gear then it destroyed the rest? I just want to make sure something else in the driveline didn't cause this so I don't destroy the new ones.

 

[Bondo]

Re: Gears in upper unit destroyed ...

1985 Mercruiser 260...

I just recently replaced all of the seals, water pump, etc... in my outdrive. all of the gears and bearings looked great. Got everything cleaned up and re-assembled per the factory manual and it was all working good.... Until this Saturday.

I had spent most of the morning pulling people on the wakeboard so it was a lot of stop and go. Later in the afternoon we took a cruise down the lake (probably about 1.5 hours cruising around 3000 rpm's) and I heard a couple "pops" and the boat quit moving. Today I finally took the drive apart and found the gears in the upper unit completely destroyed, and it also ate up the inside of the gear housing pretty good in a couple spots. I attached a couple pictures for reference.

What do you all think? Can I replace the gears/bearings/races and be OK or should I get a whole new upper unit? What might have caused this, maybe broke a tooth on a gear then it destroyed the rest? I just want to make sure something else in the driveline didn't cause this so I don't destroy the new ones.

Ayuh,.... Buy yerselff a Brand New, Guaranteed SEI drive, 'n don't look back....

Don't really matter Why she Blew,... Lack of oil usually wipes out the top end 1st...
All those gears are now dust in the lower unit,..
It'll never last,....

Btw,... iboats has those SEI drives.....

 

[Jason 641]

Re: Gears in upper unit destroyed ...

That's what I figured .. have buy a new outdrive, I was hoping for better news though

The fluid was still full and no signs of water ... just a lot of metal shavings.

As far as getting a new outdrive, what is compatible with what I have? I know when I ordered all the seals and stuff everything was the same for my drive and an alpha 1 gen 1. My outdrive serial number is A420760 if that helps. Just want to make sure I get the best (strongest) drive I can that will still fit my existing set up.

EDIT: 1 more question... I notice the SEI drives come in 1.47 and 1.62 ratio, currently mine is stamped 1.50. should I go with a 1.47 and call it close enough or would going up to a 1.62 be better? I'm thinking 1.47.

Thanks!

 

[NHGuy]

Re: Gears in upper unit destroyed ...

Yah, get a 1.47 or you throw off prop pitch.