assembling the case

[Bigbill]

I was taught how to assemble husqvarna chainsaws. When we assembled the case. We experienced the crankshaft being snug. We took a cold chisel opposite the rod and gave the crank weights a light tap to relieve the binding pressure on the crankshaft.

I do the same thing on the dirt bike cases too. You can feel the before and after on turning the crankshaft. I use the assembly tools and disassembly tools. But there can that little stress between the crank studs. Just a slight tap will eliminate this stress with a tapered chisel. Your crank bearings will thank you.

 

[fran...k.]

There are likely various ways to get the balls of the bearings perfectly aligned in the groove, which I suppose your method described above is one approach.

Where would you put the space in the crankshaft/bearing/case assembly? I pull the drive side tight put the timing side bearing tight to the crank/spacer and leave the timing side bearing where it falls which is not hard against the seal retainer piece. I have reason to believe this is not the correct method but the connecting rod seems centered and it has worked for me.

Another amusing thing is just before the locating pins engage spin the crank and see how much the cases wobble around.

Fran

 

[Bigbill]

Opposite the rod bearing inbetween. The weights I insert a new clean tapered flat chisel between the weights and a light tap will open the stressed area back to normal. This puts both ends of the outer shafts inline.

Sometimes a tap on the flywheel side and out put shaft is needed so the crank weights are centered. Then tap the weights with the chisel or wedge. To relax the stress.

If the crankshaft is tight in the case when you assemble it this process will help you free it up.

 

[justintendo]

i bought a used set of the factory husqvarna assembly tools, otherwise known as the "mangle", they work awesome! no fiddling around after installation. eurojamb makes a replica that is a tad pricy but its a nice tool. i like how it has the big crank, you can really feel the cases go back together nicely

 

[dartyppyt]

Ok so your going to stick a chisel in there and knock all the special paint I applied in the webs to prevent mag rot?
Then you have chances of getting that stuff knocked in bearing.

Once them journals are set perfect with dial indicator, I don't hit them with nothing! I've pressed those with big force to get them in tolerance and pressed them lightly as well. That's why they say when it comes to cranks. Hammer stays in the tool box.
That's why god invented case splitters, bearing seperators and presses.

If that crank don't spin on its own like it should than you got bearing pressed in wrong.

 

[Bigbill]

No I put the chisel between the crank weights in the middle.

I do not harm the case. I do not touch the case.

 

[dartyppyt]

Bill,

Not beating you up but I don't get why you still a chisel in there?

If it is assembled correctly, pressing bearings in and pulling the crank through lowering race of bearing.

Why is that necessary unless you have a tight fit from not doing the above?

That crank out to spin freely or something is wrong.

Like sprocket out put shaft. If bearing is not pressed in correctly (meaning tight) then that shaft is hard to turn.
If done correctly, is spins freely.

Why would you use a chisel in there to chance knocking your crank cheeks off from setting them with a dial indicator?

 

[Puckerbush]

When I assemble a motor, I freeze the six bearings and the crank. Then I place the two cases in my Weber BBQ and heat them to about 350 degrees. Be sure to install the mag and counter shaft flange and the clutch side retainer flange so the bearings have something to bottom out on. The frozen bearings should slip into the bearing journals. Sometimes they need a slight tap to bottom out. Then I install the main seal and reheat the left side so the main bearing is at temperature. I then slip the crank into the main seal and left main bearing until it bottoms out. When every thing is placed into the case (left side) I grease all shafts that will be mating with the right case half, along with the mag side of the crank and slip the case onto the crank and counter shaft. I lightly tap with a rubber mallet until the two case halfs are together enough for the screws to start. I then bring the two cases together evenly by screwing them in.
Its a good idea as you bring the cases together, to spin the counter shaft to make sure nothing is binding.

 

[Bigbill]

I use the assembly tools. But I check the crank for binding. Since the rod pin is offset from the centerline of the crank it can be stressed. I check for that stressing it doesn't hurt the alignment of the crank shafts. Be gentle.

 

[Motosportz]

Once them journals are set perfect with dial indicator, I don't hit them with nothing! I've pressed those with big force to get them in tolerance and pressed them lightly as well. That's why they say when it comes to cranks. Hammer stays in the tool box.

 

[Kartwheel68]

I use the assembly tools. But I check the crank for binding. Since the rod pin is offset from the centerline of the crank it can be stressed. I check for that stressing it doesn't hurt the alignment of the crank shafts. Be gentle.

If you use the correct assembly tool, and use it properly there is no stress on the crank, thats why the tools exist.

 

[Puckerbush]

After considering the binding issue, I'm going to fabricate a tool that "pulls" the right case half onto the main mag side bearing thereby eliminating stress from downward pressure. I was thinking to weld a fine threaded bolt onto the end of a crankshaft nut. Then make a plate (offset equal to that of a mag cover) with a hole in center for bolt to fit through that will bottom out on mag cover surface, Screw the tool onto the crankshaft, fit the plate over the tool, and tighten a nut against plate thereby "pulling" the crank into the main mag side bearing. This is all still in my mind but in theory it should work. I can also add a little heat to the bearing to ease the transition.

 

[justintendo]

After considering the binding issue, I'm going to fabricate a tool that "pulls" the right case half onto the main mag side bearing thereby eliminating stress from downward pressure. I was thinking to weld a fine threaded bolt onto the end of a crankshaft nut. Then make a plate (offset equal to that of a mag cover) with a hole in center for bolt to fit through that will bottom out on mag cover surface, Screw the tool onto the crankshaft, fit the plate over the tool, and tighten a nut against plate thereby "pulling" the crank into the main mag side bearing. This is all still in my mind but in theory it should work. I can also add a little heat to the bearing to ease the transition.

you are more or less talking about the factory tool, no? there are originals floating arounf but a repro is available.

http://www.eurojamb.com/husqvarna-crankcase-assembly-tool-as-nos-250-400-430-500-ahrma-p-1735.html

 

[Kartwheel68]

Exactly, the proper tool prevents all binding and eliminates the need to hit your crank with a chisel...

But if all you want to do is pull the crank into the case half, you can do that with a crank nut and an appropriate size spacer like a big socket.

 

[84scrambler]

I used two pieces of a pipe that were cut off and the wrench goes in there too as a spacer to pull the crank in. Started with one then two then add the wrench and after that its there. I do like those original tools tho.

 

[justintendo]

yes, something simpler can be made to work, but the original tool works well. someone posted here months ago selling several mangles, some splitters, some auto clutch pullers and some crank gear pullers. i had to dip into savings and go for it..

 

[jimspac]

I remember that one fine builder said all you do is because when you assemble, everything is set to the left centercase and that binding would be felt until the crank was shifted to the right. He used a leather mallet on the left end of the crank to slide the spacer on the right stub end to contact. A light tap with a 2 lb. soft mallet should accomplish this