Stihl 025 Could use some advice on replacing bearing and seals.

[HarleyT]

Why would you need to "drive" or "tap" the seal into place?

 

[HarleyT]

Which part # seals did you buy? There are two different ones, one for when you have the engine off/apart, and one
if you replace just the seal without taking the engine apart.

 

[HarleyT]

Here is a bulletin.

 

[Roy Hockett]

Why would you need to "drive" or "tap" the seal into place?

Harley T, I did not think you can just push the seals into place with fingers. I am not understanding about why you think the Stihl plastic case has to been split in half. The motor has to bolted into the bottom 4 holes. I have downloaded the shop manual but have misplaced it on my computer. Where I can I find the inbox on this site?

 

[HarleyT]

I never even suggested the Stihl plastic case could be split in half.

Just confusing trying to follow your thread here.

Just put the seals on before putting on the crankcase/cap bottom.

Which seal part number did you buy? The part numbers are listed on page 3 of the Tech bulletin I put up.

 

[TheTone]

Roy,
take the entire engine out, pan and all. With the pan and cylinder separated, the seals slip onto the crankshaft. You coat them and all mating surfaces with sealant (I think you mean Yamabond 4, and I agree wholeheartedly with that choice). You will see the "slots" that the seals fit in on the cylinder. The pan also has similar "slots", and you fit the parts together. Make sure the seals fit in place correctly in both parts. The open side where you can see the springs in the seal go inside - closed sides go outside. Pay attention to the manual to make sure you get the pan oil pump seat on the correct side. Then, with sealant in place and parts held together, place the whole engine in its seat in the housing, insert the screws and tighten. This is the way the manual says to do it. If it seems like you need three hands to do this, there is another option. You can use spacers (couple of nuts) and assemble the engine without putting it in the housing. Run the screws up snug but not to the final torque. Let the Yamabond set up for a day or two. Then remove the screws carefully, in a crisscross pattern, and set the engine in place. Tighten the screws a little at a time, again in a crisscross pattern, up to a final torque of about 90 inch-lbs. I know it sounds intimidating, but it's not rocket science. I'm only 4 years younger than you and have been doing this stuff less than a year.

 

[TheTone]

I know all this is confusing. You are getting posts from people who have been buildings chainsaws for years and have forgotten what it's like when you don't know s**t from Shinola. If you can't make sense of it all, click on my avatar and click "start a conversation". This is a private message and I will be glad to help you one-on-one and walk you through the process. That's what this site is all about - helping people who need help.

 

[Roy Hockett]

I never even suggested the Stihl plastic case could be split in half.

Just confusing trying to follow your thread here.

Just put the seals on before putting on the crankcase/cap bottom.

Which seal part number did you buy? The part numbers are listed on page 3 of the Tech bulletin I put up.

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I never even suggested the Stihl plastic case could be split in half.

Just confusing trying to follow your thread here.

Just put the seals on before putting on the crankcase/cap bottom.

Which seal part number did you buy? The part numbers are listed on page 3 of the Tech bulletin I put up.

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STIHL 021, 023, 025, MS210, MS230, MS250 CRANKSHAFT BEARINGS & SEALS REPLACES STIHL ,9503-003-0340, 9638-003-1581, 9639-003-1585 ,

SPECIFICATIONS ON OUR HIGH PERFORMANCE BEARINGS:

• Wide temperature range Mobil Polyrex EM2 (-40 to +350 degrees) lubrication
• Noise tested before and after lubrication
• Passes V2 noise vibration standards for smaller bearings and V3 standards for larger bore
• Matched ABMA grade 10 precision balls for roundness
• Finely honed superfinished raceways for long life and low noise
• Meet or exceed ABEC 3 tolerances for high quality level

I ended up getting these off of Ebay. I did not purchase the Stihl parts. The Stihl dealer close by wanted $24 each for seals and same for each bearing. I finally got around to reading the service manual and now I understand that the seals are put in at the same time as the bearing. It actually surprised me that it was this way. Trying to make it a lot more difficult then actual is. The manual and you guys have helped a lot. I am new at this type of web site sorry to make it more confusing than it really is.
Thank you Harley T
Roy Hockett

 

[Roy Hockett]

I know all this is confusing. You are getting posts from people who have been buildings chainsaws for years and have forgotten what it's like when you don't know s**t from Shinola. If you can't make sense of it all, click on my avatar and click "start a conversation". This is a private message and I will be glad to help you one-on-one and walk you through the process. That's what this site is all about - helping people who need help.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
The Tone
I appreciate your patience. This is the first and only chainsaw that I have done. I finally got around to reading most of the manual. Need to print out a few pages on it. I finally got it in my head that you can put the bearing and seals in at the same time. I ended up driving up to Honda and bought some Hondabond 4. This is the bearing I got off of Ebay.

STIHL 021, 023, 025, MS210, MS230, MS250 CRANKSHAFT BEARINGS & SEALS REPLACES STIHL ,9503-003-0340, 9638-003-1581, 9639-003-1585
SPECIFICATIONS ON OUR HIGH PERFORMANCE BEARINGS:

• Wide temperature range Mobil Polyrex EM2 (-40 to +350 degrees) lubrication
• Noise tested before and after lubrication
• Passes V2 noise vibration standards for smaller bearings and V3 standards for larger bore
• Matched ABMA grade 10 precision balls for roundness
• Finely honed superfinished raceways for long life and low noise
• Meet or exceed ABEC 3 tolerances for high quality level

I have not got my parts from Ebay seller yet. I am going to print out a few pages and with the help of you guys, I should do ok. I may end up starting a conversation with you when I get into a stump. I can put my phone number out there on a private message if necessary. My real weakness is carbs. I job for years was refrigeration and most of it was low temp like -110 F below. Also have done a lot of liquid nitrogen and liquid oxygen work ( minus 300 below) but this stuff just tries my patience because it is just new. I hope this ebay bearing and seals will be ok. Stihl wanted about $100 or about $24 each for bearing and each seal. I will take you up the private message if I get into a bind. Thank you The Tone.
Roy Hockett

 

[drf255]

Roy,

Much of the confusion here lies in the fact that there are two basic saw engine designs, a pro-style saw and a clamshell motor.

Pro-style saws have the entire case the holds the crank/attached oiler/tank mounts integral to it. The case is made of metal, the cylinder unbolt sand pulls off the top of it with 4 bolts. And the case needs to be separated or "split" to get to the bearings to change them.

Your saw, the 025, is a clamshell. The entire engine is removed from the base of the saw (aka case) and then the lower pan unbolt from the engine. The crank, bearings and seals can be pulled right out and changes. No "case splitting" is needed.

You can assemble saw right in place. Many say, as above, to use spacers to bolt the motor together with the bottom cap screws and let the sealant set up for a day before installing into the case. I've done it both ways and it's made no difference.

There's got to be a member here close to you. I'm sure someone would give you a hand if you stopped by with a 6 pack.

 

[Roy Hockett]

Roy,
take the entire engine out, pan and all. With the pan and cylinder separated, the seals slip onto the crankshaft. You coat them and all mating surfaces with sealant (I think you mean Yamabond 4, and I agree wholeheartedly with that choice). You will see the "slots" that the seals fit in on the cylinder. The pan also has similar "slots", and you fit the parts together. Make sure the seals fit in place correctly in both parts. The open side where you can see the springs in the seal go inside - closed sides go outside. Pay attention to the manual to make sure you get the pan oil pump seat on the correct side. Then, with sealant in place and parts held together, place the whole engine in its seat in the housing, insert the screws and tighten. This is the way the manual says to do it. If it seems like you need three hands to do this, there is another option. You can use spacers (couple of nuts) and assemble the engine without putting it in the housing. Run the screws up snug but not to the final torque. Let the Yamabond set up for a day or two. Then remove the screws carefully, in a crisscross pattern, and set the engine in place. Tighten the screws a little at a time, again in a crisscross pattern, up to a final torque of about 90 inch-lbs. I know it sounds intimidating, but it's not rocket science. I'm only 4 years younger than you and have been doing this stuff less than a year.

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The tone
I have got the bearing on just fine. I ended up using a two jaw puller to get bearing off. I cooled off the shaft and piston is dry ice and cooled the shaft down for about $3.00 worth of dry ice and they slipped right on with a small tap of a deep well socket. I got the short side shaft seal on very easily with a little grease. The longer shaft side not so good. I greased shaft and seal but the seal stopped at the location where the C clip is located. Tried to wedge it on and actually the inter O ring popped out of the seal itself. Tried it three time and seal O ring came off each time. I may have screwed up the seal so I have ordered another set of seals. What is the trick of getting the seal over that C clip ridge on the long half of the shaft? What I was doing wrong but I am sure I screwed up the seal on that side. I have not got the botton cap on the cylinder as yet. Now I wait for the second set of seals to arrive. Could you give me a hint of what I was do incorrectly. I have thought maybe I need to fill in that crack or C clip slot of gasket compound and let it semi harden up. Is that a possibility? What is your suggestion on this.

Thank you
Roy Hockett

 

[TheTone]

What is the trick of getting the seal over that C clip ridge on the long half of the shaft?

Some people wrap a piece of photographic negative around the shaft and slide the greased seal over that. Others use pieces of thin aluminum can and do the same (I would be concerned about those sharp edges, however). Actually, I have never used either method. I slide the greased seal up to the slot and gently pull one side of the seal up a hair from the shaft and toward the bearing. Slight pressure from the opposite side helps. This gets one part of the lip over the slot, and then you can gently work the rest of it over. Key words here: gently and slowly.

 

[Roy Hockett]

Some people wrap a piece of photographic negative around the shaft and slide the greased seal over that. Others use pieces of thin aluminum can and do the same (I would be concerned about those sharp edges, however). Actually, I have never used either method. I slide the greased seal up to the slot and gently pull one side of the seal up a hair from the shaft and toward the bearing. Slight pressure from the opposite side helps. This gets one part of the lip over the slot, and then you can gently work the rest of it over. Key words here: gently and slowly.

------------------------------------------------------------------------------------------------------------------------------------------------------------------]
I tried the gentle method first and it was solid wiggle slight and no budge . Next tried socket and a tap it on. ( bad idea) that is when the inter O ring popped off. Tried a few other times and each time internal O ring came off. At this point I have reordered another set of seals. Film would be a good idea. Maybe I can come up with some old film slide next time. Thank you The tone for the advice. It is helpful.

Thank you
Roy Hockett

 

[Roy Hockett]

Some people wrap a piece of photographic negative around the shaft and slide the greased seal over that. Others use pieces of thin aluminum can and do the same (I would be concerned about those sharp edges, however). Actually, I have never used either method. I slide the greased seal up to the slot and gently pull one side of the seal up a hair from the shaft and toward the bearing. Slight pressure from the opposite side helps. This gets one part of the lip over the slot, and then you can gently work the rest of it over. Key words here: gently and slowly.

I may try some aluminum heating cooling tape or even some blue painters tape may work.
Thank you Tone

Roy Hockett

 

[MartDalb]

watching thread here, very nice info, I have to do this installement soonish myself. I did try the "aluminium can way" a while ago on a Husq 254xp, worked like a charm, just make sure no edges catches the seal when you pull the aluminuim out. I'm very new to saw repairs, and I had no issue doing it.

 

[HarleyT]

Always used a microfiche card.

Maybe play some Led Zeppelin and give it a quaalude? {1980's tactic}....

 

[TheTone]

I may try some aluminum heating cooling tape or even some blue painters tape may work.
Thank you Tone

Never thought of that, but the thin aluminum film HVAC tape with the blue plastic that peels off the sticky side would be perfect for this job!

 

[TheTone]

Always used a microfiche card.

Maybe play some Led Zeppelin and give it a quaalude? {1980's tactic}....

Ludes were quite the rage back in the day. But it would never be able to make a straight cut again.

 

[HarleyT]

MS714.....

 

[TheTone]

MS714.....

Which is not a new model Stihl chainsaw...