How to Split a Chainsaw Crankcase Without a Puller

Topic: How do you split cases?  (Read 4073 times)

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I am pretty certain I need to split the case on both my MS660 and MS440 saws to replace seals and possibly bearings.
Husky sells a neat tool to split cases - I think the tool runs around $100.  Would rather not spend $100.
How do you all split cases without damage?

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One With Wood
LT40HDG25, Woodmizer DH4000 Kiln

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Without damage? I bought the tool. My Husky tool, which works on most Husky saws, was less than $60. Used it once on a Stihl MS360 also. I think Stihl uses something different to split their saws. You might ask at the dealer.

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Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

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I use Husqvarna's tool, but you don't need to split the case to change the seals.

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I split mine very carefully with a very thin pry bar. Never damaged the case or the gasket. On my brush saw there was just 4 short corner pins to ease out of.

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�No amount of belief makes something a fact.� James Randi

1 Thessalonians 5:21

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Never.....EVER use a pry bar to split cases.......

The Husqvarna splitter can be purchased for 1/3 of that price.
Just gotta talk to the right dealer.......

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J.Miller Photography

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Lots of stuff shouldn't be done, but they get done just the same.

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�No amount of belief makes something a fact.� James Randi

1 Thessalonians 5:21

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Get yourself a piece of angle iron that is long enough to lay across the bar studs and over across the crank.  Burn or drill a couple holes in one face of the iron so you can fit the flat section over the studs and down over the crank - 3 holes.   Bolt the iron down to the bar studs with the nuts.  Attach a two jaw puller to the angle iron over the crank.  Heat the case around the bearing pocket with a small propane torch or electric heat gun.  Take your time and dont burn the paint.  Apply pushing pressure with the puller over the crank.  Make sure all the bolts are out and - Bingo its apart.  If the bearing stays in the case, heat the pocket and knock it out with a socket.  Use a new case gasket, new bearings and new seals on reassembly.  Dress the gaskets with loctite 515 or 518.  518 sets quicker that is the only difference.

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Heat the case to 300f.  The magnesium expands to allow the steel bearing to fall away.  Same on reassembly.  On reassembly you can put the case half in a toaster oven on 300 for 15 minutes.  Make sure all the plastic bits are out.  Put the bearing in the freezer overnight.  The bearing will fall right into the case.  Here is a video;

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There's a number of methods that all work .My prefered method is to use heat gun to warm the bearing pockets .Put a crankshaft bearings and all in a deep freeze for a couple of hours .Tap the crank on a board and the bearings usually fall off .

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Reassembley you can use several methods .Install the bearing in the case halves first or on the crankshaft ,again heat/cool .I've done it both ways .

However it's done don't beat on the danged saw like you are driving a railroad spike .Somethings will go awry if you do ,sooner if not later .

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How to Split a Chainsaw Crankcase Without a Puller

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