046 bearing removal

[highsiera]

It's cold and raining so I'm back to the 046 project. I've got the case split, crank came right out, but I'm having a bit of trouble removing the shot bearings from the case halves. Now the clutch side, that was no problem, a little heat with the propane torch on the case around the outer race then two hits with a deadblow and a brass drift and it fell right out. But I'm not sure how to even approach the flywheel side. It sits right in a pocket molded into the case and only the edge of the inner race pokes through. I'm not afraid to put the heat on it, but I'm afraid I'll damage the case if the drift slips even just a little bit. I know a few of you have replaced these so any tricks or techinques would be graciously obliged.
Moving on to the next logical question, how do you all install the new bearings so everything is straight and true? I did a few searches and didn't find exactly what I was looking for.
Thanks in advance, Brian.

 

[Dadatwins]

I use some heat and an old socket that fits exactly through the hole and onto the bearing. Tap on the socket and the bearing will fall out. Once heated it should not take that much effort for it to pop out. good luck.

 

[Lakeside53]

If you use heat, you have to be very quick as the bearing also expands... I use a socket and just press them out cold using a 2 ton arbor press. Sometimes they are in really tight, but they all come out.. Make sure you casing is suported on the entire surface, or you can crack it.


Insertion - It's easy on the flywheel side as it's just a matter of heating the case to 300 for a while (I bake mine in convection oven) and the bearing just drops in the hole. If it doesn't, you don't have the case evenly heated or hot enough.

The clutch side can be a bear as it has a steel insert that even when heated is a tight fit, and you can get the bearing off-true and jambed real easy. I insert mine cold with a little lube from the outside and use the inner case as the true surface. Push it though with press (you cannot just bang it in, and you shouldn't as you will damages the race) until it's just slightly lower than required, mount the oil pump and press it back from the inside until it just touches the pump.


I wrote this up with pictures a while back.... check this thread out:

http://www.arboristsite.com/showthread.php?t=40590

 

[highsiera]

Thanks Dada, and of thanks Andy. Naturally Andy, I found your 066 thread right after I posted my question, great pics. I ended up "engineering" a predd using a 6 ton bottle jack, a PT 2x4, and the steel beam supporting my house. I used a socket to push and a block to cushion the case and distributed the force evenly. A few pumps on the jack and it popped right out real smooth.
In the 066 post, you demonstrated pulling the bearings into the case with the crank (or so it appeared). for the 046, do you press the bearings into the case halves and then pull the crank into the bearings?
Thanks again, always great info. B

 

[Lakeside53]

You may have misinterpreted the picture... The bearings are always seated first, then the crank is pulled onto the respective bearing.

 

[Al Smith]

A trick,older than the hills is to heat the inner race,once installed in the case halves,with a soldering iron.Having first frozen the crankshaft in a deep freeze.They pop right in .

As a rule,some well placed heat will get them out.I had a thread some place,here or somewhere else,with pictures.The main thing is,don't beat em like a red headed step child.It doesn't take much to mess them up.

Edited after thought: You can also heat the case and freeze the bearing for installation in the case halves,this works well,followed by the soldering iron trick.Another way to skin the cat,so to speak.

 

[Lakeside53]

I don't do the the soldering iron method.. It can wreck the bearings... They have poly (plastic cages), and, the differential heating can damage the deep groove bearing races. In any case, pulling the crank on isn't all that difficult, even without the factory tools. Just my 2c...

I've tried freezing the bearings - never found to to be any help on the clutch side. The extra 30 degrees differential didn't buy much with the steel on steel insert.

 

[Al Smith]

You are probabley right about that.I never did an 046.I did use that method on 038's ,048's and one 066.The soldering iron deal came right outta the"book" on the 048.

 

[highsiera]

Gotcha Andy, thanks again. I'm moving careful and slow, plus I have an extra 044 case and crank to practice on. It's been said before, expensive saw to learn on, but so far everything has been smooth. I'm going to try the freezer/ oven trick if for no other reason than to get a rise out of mrs. Siera who doesn't even flinch anymore more when she opens up the dishwasher and discovers an oil pump, a brake band and 2 case halves..

 

[Lakeside53]

Be real careful if you use a standard radient oven.. shield the case with foil... A convection oven does work best.

You'll find the flywheel side bearing pops in with rattle room...