Stihl AS and ZS Tools

[5555555]

I need to split the crankcases of a couple 066s and haven't had much luck with just heat. It looks like the AS and ZS tools wouldn't be too hard to fabricate. Can someone who has them tell me how thick the bottom steel plate on each one is? I can't see buying new ones for the little amount that I'd use them.

I've read all the posts on crackint the cases. Has anyone had good luck with splitting cases without using the Stihl tools?

Thanks,

Jim

 

[Lakeside53]

I need to split the crankcases of a couple 066s and haven't had much luck with just heat. It looks like the AS and ZS tools wouldn't be too hard to fabricate. Can someone who has them tell me how thick the bottom steel plate on each one is? I can't see buying new ones for the little amount that I'd use them.

I've read all the posts on crackint the cases. Has anyone had good luck with splitting cases without using the Stihl tools?

Thanks,

Jim

I've split many cases without the specialty tools, but ended up buying both he AS and ZS to make life a lot easier and more precise.

I used a combination of angle iron bars, pipe spacers, standard and modified pullers, presses and parts from old clutches (for the left hand thread). Lots of measuring, drilling and cutting required, but for one off you can figure it out.

Splitting is easy: The clutch side - just use an angle iron bar mounted over the bar studs with a hole drilled for the crank. Then mount a standard puller onto the bar and PUSH the crank out. Use a press to gently push the crank out of the flywheel side. DON'T use an impact wrench - the impacts will damage the bearing as they are transferred directly to the balls/races.

Assembly is more difficult.... You can use a press to push the crank onto the flywheel side bearing (which can be bad for the bearing as it pushes the inner race against the outer bearing case), or a nut with multiple spacers to pull it on with the flywheel thread. On the Clutch side, same idea, but you need to use the center of an old clutch with left hand threads to pull the case/bearing onto he crank. Use several spacers of different lengths changing them as you run out of thread. Use over-length screws to gently pull the crankcase together at the same time. It's very easy to damage the crank and bearings, so know where your pressures are being developed.


The Stihl tools are more difficult to make than they look - several adapters with both left and right hand threads, slip rings etc. I was going to do this and throw my collection of bar and adapters out, and bought the AS/ZS tools to copy (and sell copies) but decided to was way too much work.

I answer to your question, the base material is about 3/8 thick.

I'm curious.. just how were you trying to take the cases apart with heat?



You might want to talk nicely to your dealer. They MIGHT rent you the tools, or, charge you shop rate to bust the cases apart and reassemble them. It's doesn't take long if they cases are ready to work on.

 

[5555555]

I made a quick and dirty jug out of 1" angle iron. It worked, but it flexed alot. I'm not sure if it was because the case was so tight, or the jig was just not strong enough. It was my first try. I'm sure it was puttig some side pressure on the crank and case, so I thought I could fab up something stronger.

I like the idea of taking it to the shop for breaking. My understanding from reading the posts here is that once the case is apart, new bearings and seals can be installed uding heat and cold and the case can be reassembled without tools. Am I dreaming?

Thanks,

Jim

 

[Lakeside53]

I made a quick and dirty jug out of 1" angle iron. It worked, but it flexed alot. I'm not sure if it was because the case was so tight, or the jig was just not strong enough. It was my first try. I'm sure it was puttig some side pressure on the crank and case, so I thought I could fab up something stronger.

I like the idea of taking it to the shop for breaking. My understanding from reading the posts here is that once the case is apart, new bearings and seals can be installed uding heat and cold and the case can be reassembled without tools. Am I dreaming?

Thanks,

Jim

You're dreaming, but that's o.k.... Yes, the bearing can be just dropped in if the case is at and even 300F (I put it in a convection oven for 20 minutes), but on an 066 the crank usually won't go on even frozen... If it does it's probably worn. I've seen a post about putting a BIG soldering iron in the bearing to heat up the inner race, but this is really bad for the bearing as it puts huge pressure on the race. A C3 fit bearing is not designed to have a big temperature differential between the inner and outer races. You'll end up with galling on the races from the point contact of the balls. You can also damage the plastic ball carriers. Stihl bearing are really expensive, so be nice to them... Buy them from your dealer - he may help out with the reassembly for a low price..

The seals always go in cold.

 

[Lakeside53]

...also, make sure you have ALL the screws out of the case. Hate to admit it, but twice I've missed one screw and busted the case...