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Case splitter tool

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After weeks of waiting found the problem in the motor. Got to replace crank... Anyone know if you have to have the "case splitter" tool to actually split the cases or could you use something else? Trying not to spend $200 on a tool for a one time use..

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yes 90% of the time they will help a lot.They are more like $70. or you can make your own,

 

lots of internet mechanics will come on here and tell you you will never need one, just a sledgehammer and chisel. 

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Go to any automotive parts store and buy a harmonic balancer puller for $20. Then go to your local hardware store and buy some various M6 bolts for mere cents.....there's your case splitter...

Kx-rebuild1_zps7c220cda.jpg

Edited by Fattonz
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Just split my cases for the first time a couple weeks ago. I got the tusk case splitting tool for only 60 bucks. Not to say you can't rig something else up but I'm glad to have this tool in my garage!

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I've used both the harmonic balancer puller and the case splitter. Both work fine. Just please don't try and jimmy rig it with a rubber mallet and a flathead, bad things will happen

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I have never used a case splitter tool. A few taps with a dead blow hammer and your all good! I Split a KX450 case this week and it had two places you could use a big flat tip screwdriver to pry against and that was all it took.

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So with what has been said I'm assuming I need the "puller/installer" tool also?

You don't need an installation tool used heat and freeze your bearings and crank 

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Please don't do the dead blow and screwdriver. It cannot be done without damage unless one half of the crank is Not press fit. Period.

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Go to any automotive parts store and buy a harmonic balancer puller for $20. Then go to your local hardware store and buy some various M6 bolts for mere cents.....there's your case splitter...

Kx-rebuild1_zps7c220cda.jpg

 

 

I use a three-prong steering wheel puller, but it's the same thing basically. :thumbsup:

 

Many cases are difficult to split without a splitter, because many engines don't use a center gasket, they use a gasket sealer between the center cases that can be tough to break loose. The first time I split my KX250 cases I thought I was going to strip the bolt holes it was stuck together so hard.

 

Using hammers and screw drivers is a lazy "don't give a crap" way to do it, and on a lot of engines you're just playing Russian Roulette doing it this way. Sorry if I insulted you guys that do it this way, but it's how I feel about that, nobody said you have to agree with me.

 

When reassembling you can heat the cases in an oven and freeze the bearings, and they will almost fall in. You can then do the same thing to install the crank, but unless you know exactly how to do it it can be tough to do quickly enough without messing up the case sealer. A crank insertion tool is good insurance against making mistakes and possibly knocking the crank out of true, which will  drastically shorten its life.

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For assembling the cases I use a puller that I made for less than $10 using parts from a local hardware store.  It is basically a piece of threaded rod (can be M6 or M8 depending on the bike) that threads into the stator end of the crank.  The rod extends through a piece of pipe that is the correct diameter to fit over the crank end but small enough that it only contacts the inner race of the left main bearing.  I have welded a fender washer onto the end of the pipe through which the the threaded rod extends, then install a hex nut onto the end of the threaded rod.  All you have to do at that point is cinch up the nut and it slowly and evenly "pulls" the case halves together.  No heating is required and way less chance of disturbing the bead if the engine you're working on uses sealant in place of a center gasket...

 

I install the left crank bearing into the left case half ahead of time.  I also install the RIGHT side crank bearing onto the crank ahead of time by freezing the crank then heating the bearing to no more than 230F.  I then re-freeze the crank/right main bearing as an assembly.  I then heat the right side case (in an oven to 250F) and the crank with the bearing installed will drop right into the right side case.  After everything has cooled and equalized I proceed:

 

P3220088_zpsd177ed32.jpg

 

P3220087_zps9ff0ec5a.jpg

 

P3220072_zps8ee4ff04.jpg

 

P3220074_zps0894628e.jpg

 

P3220076_zpsb1eb1c0b.jpg

Edited by Fattonz
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The only thing you have to be careful of with that set-up is that there is nothing between the cases that might interfere with pressing them together.  If you encounter an obstruction you might pull the left main bearing back out of the case half instead of pressing the case halves together.  But I like this set-up because it's a lot more delicate and therefore forgiving than using a hydraulic press.  If something isn't right you feel it right away.  Also, you don't have to worry about using a spacer jig between the crank webs, or affecting crank trueness, etc....

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For assembling the cases I use a puller that I made for less than $10 using parts from a local hardware store. It is basically a piece of threaded rod (can be M6 or M8 depending on the bike) that threads into the stator end of the crank. The rod extends through a piece of pipe that is the correct diameter to fit over the crank end but small enough that it only contacts the inner race of the left main bearing. I have welded a fender washer onto the end of the pipe through which the the threaded rod extends, then install a hex nut onto the end of the threaded rod. All you have to do at that point is cinch up the nut and it slowly and evenly "pulls" the case halves together. No heating is required and way less chance of disturbing the bead if the engine you're working on uses sealant in place of a center gasket...

I install the left crank bearing into the left case half ahead of time:

P3220088_zpsd177ed32.jpg

P3220087_zps9ff0ec5a.jpg

P3220072_zps8ee4ff04.jpg

P3220074_zps0894628e.jpg

P3220076_zpsb1eb1c0b.jpg

If weld a nut to the top of the all thread u can save the threads on your all thread by not using vice grips

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If weld a nut to the top of the all thread u can save the threads on your all thread by not using vice grips

 

 

Absolutely :thumbsup:  I should have done that but was too lazy   :blush:

 

I never back the nut off that far, so wrecking the threads wasn't a concern for me...but that would definitely be a more professional thing to do ;)

Edited by Fattonz

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if I have tough to split cases after I get some tension on them I put a bit of heat to them with a heat gun it don't take much

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I've watched pro mechanics and they always use a big rubber mallet.

 

 

And I've NEVER seen a TRUE professional mechanic just beat things apart. Owning the correct tools for a job is part of what distinguishes a pro from an amateur.

 

I'll guarantee you there isn't a mechanic in the pits at a Supercross or National that beats the engines apart with a hammer.

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if I have tough to split cases after I get some tension on them I put a bit of heat to them with a heat gun it don't take much

 

 

That's what I had to do the first time I split the KX.

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