Rebuilding stihl 044

[Mike Whitmore]

Ordered heat gun will be here tomorrow..so re assembly starts tomorrow evening

 

[Mad Professor]

I try to take stuff off in assys and put into zip locks to keep track of things. Take a sharpie and draw a picture on the bag for stuff like different length screws /bolts.

For bearings and such a chisel or punch mark to note orientation.

A stack of stuff like a clutch assy run mechanics wire through the parts just as they came off. Stuff like this, note some washers have thrust sides and you don't want to flip them, same as clips.

take pictures

hope this helps.......

 

[BuckthornBonnie]

FW Bearings with “open, ball side” towards crank. The Stihl proprietary clutch bearing is with the step pointed towards the oil pump.

 

[drf255]

Like Buck said above.

I use a propane torch, a heat gun never gets it hot enough for me.

The PTO bearing, you need to put the oil pump on to set its depth. The machined lip/bearing extension goes towards the pump, it retains the seal.

If you don’t have special tools, do what I say below.

Freeze crank in a ziplock bag overnight. Warm the Fly side and drop the bearing in. When the bearing soaks up heat, it will have a different feel to it. Wait 5 minutes.

Take crank out of freezer, push it right into that hot Fly side bearing. Bottom it out. The let the whole thing cool, freeze it in a bag again for an hour or two.

Put oil pump on. Heat the pocket and drop the PTO bearing in. Let it soak up heat. Grab case, add gasket. The PTO side will now slide right over the cold crank. Use the case bolts to pull it all together and when done, use a punch in the center of the crank on both sides to stress relieve/center the crank.

The above will get a Stihl case together without any fussing or BFH use. The MattyO tool works the best, but it’s alot of money if you do few saws.

 

[Mike Whitmore]

Do i need to freeze the flywheel side bearing to let it slide into pocket? For after warming fly side? And or freeze pto bearing prior to dropping it into pocket to set against the oil pump?

 

[BuckthornBonnie]

It helps, but isn’t always needed and results in condensation. It can be done without freezing the bearing.

 

[Mike Whitmore]

Was wondering could a lil 3n1 oil help to reduce possibility of condensation damage on bearings?

 

[BuckthornBonnie]

Oil reduces it, yes...

 

[drf255]

Do i need to freeze the flywheel side bearing to let it slide into pocket? For after warming fly side? And or freeze pto bearing prior to dropping it into pocket to set against the oil pump?

Not needed. Even if some condensation occurs, it will get so hot it will evaporate.

 

[BuckthornBonnie]

Agreed on the freezing. I sometimes cover the bearings in oil if I freeze them before install, but not always. The condensation shouldn’t bother things unless it doesn’t evaporate as doc said.

The key part is getting the case up to temp and allowing expansion.

 

[siouxindian]

Like Buck said above.

I use a propane torch, a heat gun never gets it hot enough for me.

The PTO bearing, you need to put the oil pump on to set its depth. The machined lip/bearing extension goes towards the pump, it retains the seal.

If you don’t have special tools, do what I say below.

Freeze crank in a ziplock bag overnight. Warm the Fly side and drop the bearing in. When the bearing soaks up heat, it will have a different feel to it. Wait 5 minutes.

Take crank out of freezer, push it right into that hot Fly side bearing. Bottom it out. The let the whole thing cool, freeze it in a bag again for an hour or two.

Put oil pump on. Heat the pocket and drop the PTO bearing in. Let it soak up heat. Grab case, add gasket. The PTO side will now slide right over the cold crank. Use the case bolts to pull it all together and when done, use a punch in the center of the crank on both sides to stress relieve/center the crank.

The above will get a Stihl case together without any fussing or BFH use. The MattyO tool works the best, but it’s alot of money if you do few saws.

this is very good info well written.thanks.

 

[Mike Whitmore]

Does the pto side seal go on the flywheel shaft before or after the bearing spacer? Before or onto the shaft of number 11?

 

[pioneerguy600]

The seal installs into the PTO side bearing shell extension. # 11 will push in after.

 

[Mike Whitmore]

Gotya...so is it normal for the crank to ‘tighten up” (not ratate as easily) after installing and tightening the clutch? If i loosen the clutch it is back to ratating more freely...also with new bearings and case tightened the crank didnt rotate as freely as with old bearings

 

[Mike Whitmore]

The seal went in first then the bearing spacer fits down right insight the seal and fits nicely sealing it well.

 

[huskihl]

The bearings will have a side load after screwing the case halves together. I use a hammer and center punch in the center of the crank and give it a couple raps on each side to relieve the side load. Try one side and check...try the other... back and forth til it spins freely. If you have the seals in place as well as the worm bushing, it'll have some resistance and be more difficult to get it right

 

[pioneerguy600]

Gotya...so is it normal for the crank to ‘tighten up” (not ratate as easily) after installing and tightening the clutch? If i loosen the clutch it is back to ratating more freely...also with new bearings and case tightened the crank didnt rotate as freely as with old bearings

As long as you have either # 14 or #15 installed in the right direction the clutch will tighten down with no problems or damage. What you do need is the correct washer for the clutch you have, the shape of the back side of the clutch dictates which washer/shield is required, otherwise the clutch body will contact the washer/ shield and cause a hard turning crank.

 

[Mike Whitmore]

Didnt change any of the parts outside of the seal...odd....i wonder if wrong clutch and washer were on it?

 

[Mike Whitmore]

Probly cut with it over 14 years...several hundred cords of wood..sold wood for a couple years

 

[pioneerguy600]

If its run for 14 years then its likely just fine, the big washer/shield contacts the end of the # 11 bushing but the oiler drive # 12 and 13 must be able to rotate freely from contact with the shield. That shield is only there to prevent a broken clutch spring from damaging the oil pump if one breaks. I have seen a couple pumps that were badly damaged by broken springs when the shield was left off when a clutch was changed.