Flushing out the crank case

dastevoe

Wood Hacker
Joined
Jan 3, 2009
Messages
135
Location
Norwood Ontario,Canada
I've got my "doner "026" apart and clean as a whistle now.
Jug is off and needs new p&c ,lost a small piece off ex. side skirt (not to be found).When crank is spun by hand the bearings feel good.If I pop out the seals and flush the CC with diesel should this be ok ? I'll also be able to visually inspect the bearings when seals are out.
I just don't want to get into separating the CC if I can avoid it.
Is using compressed air (low pressure) at flushing ,a NO-NO ?
Steve
 
If it grenaded a piston it would be my suggestion to split it . The reason being if just one tiny itty bitty bit of loose aluminum gets lodged in a bearing it will do untold amounts of damage .

If a bearing hangs it could spin within the bearing pocket in the case ,not good at all .

Generally speaking a piston that just got scuffed usually won't throw aluminum in the case .If however you saw even a little of it in the case the possibilty exists it could have hit a bearing .
 
Try diesel first, blow from outside in.

Use straight gas the last time to wash out diesels and evrything else. Just don't leave any in there when you are done.
 
Steve, Al is right, it is probably best to open it up and inspect the bearings with a magnifier to be sure, but it is easy to mess things up if you plan to use a hammer. I have the STIHL tools to split a case safely and correctly, and put it back together without using a hammer, and it makes the job fast and easy, but the tools are pricey.
Instead of diesel gas like Magnus uses, which is OK, I just use a can of brake cleaner spray to flush everything out. It is under pressure, doesn't burn too bad when it gets in your eyes! :cry:
and dries clean. If you pull the seals then it would work well to spray through the bearings from both directions.
I have some pics of splitting the case if you want to see them. I had an 034 rebuild posted at Magnus site and something happened to the Photo Bucket links and I just have not made time to go get them all reconnected.
I will try to do that tonight, and I guess I could post them here too.
Eddie
 
You can split them without the special tools if you know how ,I've done bunch of them and never screwed a thing up---- but if you don't know how best not go there .
 

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Sawcollector, I wouldn't mind seeing pics of how you do it. I just ordered a Husky splitting tool. It was $67.80. I made the mistake of splitting the saw and putting it back together with questionable bearings. I chickened out on running them, so I ordered new, which came in today. $24.48, for both bearings, is cheap insurance.
 
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So Al after you heat the c/c halves do the bearings "drop" in real quick & easy or do you have to tap them a bit? Does the crank get pressed into the bearings ,And do you warm them up again before putting the crank in (lubed with oil of course).
When I did my 038 ,the brother-in-law helped,we warmed the bearings, slid them on the crank,let it cool, then warmed the housing and put in one side(we still had to tap it to get it to go together because I think the bearing & crank sucked the heat out pretty quickly and the housing started to tighten-up),then heated the other 1/2 and same deal as before. It was my first one and was pretty stressful (I thought this build stuff was to be fun!!:what:)
Does this sound familiar to some of you guys ?
Steve
 
Here is how my Husky dealer told me to do it. You press the bearings into the case until seated. Then you assemble, using the case bolts to evenly draw the case halves onto the crank. Then you tap the end of the crank a good smack with a plastic mallet. This ensures that the bearings aren't being side loaded. This is the same advice given to me by my Stihl dealer. I trust both of them.
 
Getting it apart is not a problem .Heat the bearing pockets and it will pry apart ,heat ,pry,heat , pry .Usually just freezing the crank and thumping it on a board will shake the bearings loose .Sometimes after freezing they about fall off ,just depends .

Putting back together could be a problem .Two methods I have used .Freeze the crank ,warm the bearing ,tap them onto the crank using a piece of tubing ,deep well socket whatever .Only tap on the inner race . Then toss the whole mess in the freezer over night . Next day or at least after a few hours in the freezer heat the bearing pockets and push one side of the crank in .Then do likewise the other .

Method two as per the Stihl instructions on 048/042 .Install the bearings in the cases ,freeze, heat what ever .Freeze the crank . If and I do mean if the bearing has no plastic cage use a soldering iron to heat the inner race,install one case half do like wise the other .

It most likely won't harm a bearing by just applying some pressure to the balls but don't thump on it .The balls and race are hard as a rock and if they get chipped failure is eminent .If you are going to press it in the case use the outer race.Use the inner for putting it on the crank .

The main thing is don't be thumping on this thing like you are driving a railroad spike .
 
If you put this much effort in it and split the case, change the bearings and seals! No need to inspect with magnifying glas then either...

If you don't want to split the case or get these parts, clean it up as best you can and put it back together. You might even find the part(s)...


When doing this I usually heat the bearing, if it is not with seal in it and put them on crank, then in throw this in freezer. Heat case a bit and on it goes.

Be very careful when doing this so the alignment is correct. No tension and spinns freely of curse... Not all or should I say most don't have a seat to push in to, just casings walls to sit in.
The position it has in the case is never the same on two models and can even be different from saw to saw in some model's...
Some you don't need to split the case to get the bearing out.

Do you have a pic of the piston so we can see a bit more?
Perhaps in the case too?
 
I have some pics of splitting the case if you want to see them. I had an 034 rebuild posted at Magnus site and something happened to the Photo Bucket links and I just have not made time to go get them all reconnected.
I will try to do that tonight, and I guess I could post them here too.
Eddie
If you need help let me know...

When you fixed that post, just copy it and paste it in here, it should work just fine.
 
Another thing...
When you inspect the bearings, assuming it is clean, turn crank over slowly a couple full turns so you feel if there is any abnormality's in the bearings.
Hold the rod gently, spin carefully, and feel and listen...
 
034 Case Split

Well I managed to get the pictures organized for splitting the case.
This is how to split a STIHL pro saw crankcase using the STIHL tools. The process is basically the same for any pro saw from a 026 to a MS 880. I realize the tools are expensive, but they do work extremely well and ensure that nothing gets damaged. I have done it with a hammer and a brass drift, and heat and cold, as Al discussed, but with these tools the job is fast, safe, and professional, without putting expensive parts at risk.
This 034 was given to me with a scored piston and a broken case half.

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Once it is stripped down to the bare case drive out the two dowel pins and then remove the screws holding the two halves together.

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I always refer to the manual since these tools are designed for multiple models of STIHL saws and cut-off machines. There are different adapters and lengths of bolts and the manual tells you what goes where.

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One tool pushes the case apart, then the other pushes the crank out, and then each tool is used again to pull the crank back into one side, and then the two halves back together.
The AS tool is for the bar stud side and the ZS tool is for the ignition side.
The AS tool is bolted to the bar studs while lining up the spindle with the crank.

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Then screw in the spindle and you will hear a pop pop pop as the crank and bearing is pushed out of the case.

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On most applications like this the bearing race that spins has a tight fit and the race that is stationary has a loose fit, so the bearing should come out of the case and stay on the crank.
Now I use the ZS tool to push the crank out of the ignition side. This is an 1125 series saw so I use the number 7 holes.

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Bolt the tool to the three threaded holes in the case through the #7 holes, then tighten the spindle and the pop pop pop happens again and the crank is out of the case.

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Next I will show you how to get the bearings off the crank, then we will go through reassembly.
Steve, is the Husky tool the one the guy posted about over on RaceSaws that reaches inside the case and pushes on the crank? I had never seen one like that and it does look to be more universal than the STIHL tools.
 
Now this is coincidental because I also have an 034 that was given to me with a damaged piston due to dust inhalation because of a faulty air filter .How about that .:)

My only comment about using these tools is the fact they are pressing against the bearing races . It obvious they work great .However in dealing with bearings it's not the normal accepted practice to press by having the bearing balls carry the load . Then too because of the design it's about the only way you can do it .
 
Now this is coincidental because I also have an 034 that was given to me with a damaged piston due to dust inhalation because of a faulty air filter .How about that .:)

My only comment about using these tools is the fact they are pressing against the bearing races . It obvious they work great .However in dealing with bearings it's not the normal accepted practice to press by having the bearing balls carry the load . Then too because of the design it's about the only way you can do it .
If pressed on inside race for crank and outside for case it is OK.
Pressing or pulling on the right place is important.
 
If pressed on inside race for crank and outside for case it is OK.
Pressing or pulling on the right place is important.
Well ,that is true too .It's hard to say without seeng exactly how that thing works .

I have no doubt if Stihl designed it there is nothing wrong with it .

In my books I have pictures of that press plus some other specialty tools .The only one I've duplicated so far is a flywheel puller . Mainly because I wouldn't use the others as much but they would be nice to have .:)
 
I guess if you are this far the bearings might as well be replaced, since Al is right, there is no way to do this without putting some stress on them.

Once the crank is out, if the bearings are to be changed a bearing splitter must be used. They don’t always need changed but since I am this far and it is an old saw and I know the man used it a lot I will install new ones. There really is no way I know of other than like these pics show to do this without causing damage to the crank. Saw cranks are two or three piece, and in some cases five pieces, not counting the bearings or rod. A press will just fold it up, and a hammer and punch can loosen the press fit of the crank pieces, so my recommendation is to get the tools or pay someone who has them, which in the long run will usually be cheaper than buying a new crankshaft!
There are several different sizes of these and I have ended up with three to do the jobs I have gotten myself into. Select one that is about the right size to slide up under the edge of the bearing like this:

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As you tighten the two bolts the separator starts sliding between the bearing and the crank and you will hear the bearing pop. Keep going until you have a good bite under the bearing:

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Now put a 2 bolt puller on the bearing separator with 2 long bolts. I keep an assortment in a special box that I keep put away so I don’t use them for something else. Now use it to pull the bearing off the crank:

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And all without ever getting out the hammer!!!

Once everything is clean and inspected I heat up the case with a hot air gun and the new bearings will just about fall in. I always have a driver tool that is just smaller than the outer race handy to tap it in till it is seated.
So now the new bearings are in the case:

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The STIHL tools are now used in reverse with the double threaded adapters to pull the crank through the bearing on one side and then pull it through the other and join the case back together. I put a little two-stroke oil on the crank to help the bearing slide on. Make sure the gasket is in place and the rod does not get pinched between the case halves, and snug it up, drive the two dowel pins back in, torque the crankcase bolts to spec, and then see if the crank spins freely.

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Once the bolts are tight the crank is tight too. This is common, and the fix is to hit the crank on both ends carefully with a dead blow hammer or plastic mallet. This releases the bearings and centers the crank, and now it spins freely.

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As I have said, the tools make the job fast and easy and do it right, so if you do not have the budget or justification for the tools then consider making them or finding a dealer willing to help you out if you already have it stripped and ready.
Steve, do us some pics of the Husky tool in use so we can see how it works.
 
Fantastic pics and explanation. :thumbup:
Very informative, nice to see how this is supposed to be done (just in case I ever end up doing this). 8)
 
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Sawcollector; I don't have the Husky tool or any specialized tools ,you must have me mixed-up with someone else .Sure wish I did !! I'll probably use Als methods.First I gotta get the danged flywheels off :X
The other 038 that I'm "magnumizing" had a godawful mess of blackish oil under the drum side cover so I suspect it has a bad seal,so I got new seals for it today as well as for the 026.Plus replaced some other worn tidbits. This "nickel & dime" stuff really adds-up :cry:
I guess thats what happens when you rescue saws that have lived an abused life and want to put them as new again (or better than new:D).
I'm interested in finding out more on putting the 044 carb on an 026 (maybe I read it in some of Brians posts ?)Does it just bolt on ? Is it a good match for a woods ported saw ?Is it a fuel hog ?
Just wonderin ? Probably won't shell out the dough though, unemployment cuts into the "toy budget".
Thanks
Steve
 
I mentioned the Husky puller. I got it today. I was able to split the case without it, but it was a big PITA. Here is a shot of the puller with the part number. It was something like $68 bucks at the Husky shop.
 

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Very nice pics Collector .:)

Dastevoe that flywheel puller is a screw type thing that goes into the threads on the end of the flywheel .

Being stingy I made one from a metric hydraulic tubing fitting ,a piece of round sock and a Ford head bolt .
 

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I just thought of another "McGiver" method of getting the bearings off the crank .

Big drill chucks use a Jacobs taper .To remove a big chuck you use tapered slotted wedges ,two of them driven in 180 degrees apart . I think about a number 3 or 4 Jacobs taper wedge should be about the correct size to drive off a bearing by getting on the inner race . Unfortunately my wedges are at my shop ,my shop is 20 miles away and it's 7 in the morning . I have no way of knowing exactly what size they are . That said though a set of Jacobs wedges don't cost that much .

Now I've removed them by using a pair of screwdrivers as wedges but it's a pain in the bottom side . You have to be darned careful not to engage the outer race or you risk trashing the bearing .A clutch side Stihl bearing is in the 30 dollar range .:O
 
Thanks for the compliments guys.
Sorry Steve, I thought it was you but it was Dave with the puller. That one is way less money than the STIHL tool, but I don't see how it would work for reassembly. I guess you could just use long bolts to start the two halves together and do it that way. What does the Husky shop manual say about putting the case back together?
That is the advantage of the STIHL tools, they are used for reassembly also, and I would guess that they might work on other brands with metric threads.
Al, it is awesome to be able to use the lathe to make your own tools. Let's see, how much is a lathe???:whine:
So I guess the next thread I need to do is on seal removal and installation...
 
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