Bearing stuck on drive shaft?

[titaniumneck]

I know pictures would probably help but my camera broke.
I have a 2003 25 hp yamaha 4 stroke outboard, the bearing at the mid point of drive shaft where it sits on the lower unit busted. Roller pins all out and retaining outer part of bearing came off all twisted up. Here's my question, the inner hub of bearing will not come off. It is like it's made to be there. It is solid on the shaft, there is a coupling right above it that is made onto the shaft, but this bearing will not budge. I really haven't hammered down on it yet, because I don't want to bend drive shaft because that's big money. Will heat work, soak it in something, muratic acid maybe. Any ideas. I know y'all guys know what to do

 

[titaniumneck]

Bump

 

[GA_Boater]

Things like this happen to me, you're not alone, TN.

I soak with PB Blaster or your favorite derusting solvent for a while. Next I heat the race and use a hammer sliding along the shaft to tap and free the race. The slide thing is so the shaft isn't dinged which could cause a weak spot to break later on. If the shaft end to race isn't too long, a long jaw puller might work.

I hope the race hasn't welded itself to the shaft if it spun.

 

[fhhuber]

Try the solvent... then heat to as high as 450F (no more!)

When those fail... get a Dremel or similar and carefully grind almost to the shaft on both sides of the bearing race that is stuck. You should be able to stick a heavy straight slot screwdriver in and pop it off. If this doesn't work, it has welded to the shaft.

 

[joeanna]

Usually on shafts, bearing races areas are machined with a "shrink fit", heated and put on cold shaft. I also use a drema with a cut off dish and put a groove or two on the race, tapped with a hammer and or heated it should crack and become loose.

 

[titaniumneck]

Appreciate all the input, I will try it tomorrow and let y'all know.

 

[lakensea]

Hydraulic press.

 

[robert graham]

Seems like a good application for a spray can of Freeze-Off (Auto-Zone or Advanced Auto)....uses very cold CO-2 blast to help move stuck parts....maybe then some heat. I use an old small hair dryer to apply heat so as not to damage any metals...

 

[Darrenmb]

Hydraulic press.

This!

 

[titaniumneck]

If using heat which part do I heat up the shaft or the old bearing?

 

[GA_Boater]

The race. You want the race to expand, not the shaft.

 

[titaniumneck]

10 4. Thanks

 

[Scott Danforth]

2nd the dremel with small cut-off wheel and a chisel

 

[titaniumneck]

Yea, it looks like it is heading in that direction, drimmel and cutting wheel. I can't complain, I bought the motor for $200 because the owner thought the motor had seized up. First thing I did was pull lower unit and motor started right up. Everything in lower unit in perfect shape except this one shaft bearing.
$200 for a 2003 25hp yamaha 4 stroke electric start not bad, $19 dollar bearing.

 

[Scott Danforth]

Cut about 80% thru the bearing in 2 locations avout 180 degrees apart, use the chisel to whack the race and it will fall apart