025 case seal questions

[paddlerdan]

I am going to change the case on my Stihl 025. What parts do I need to buy in addition to the case to do a complete job. I mean gaskets, seals, etc. Do I need RTV or Permatex? Where?

NOW lets get a bit technical--- Any Stihl techs out there? I need help clearing something up.
In the Stihl IPL for the 025 it lists 2 different crank seal part numbers.
9638-003-1581 and 9639-003-1585. These are both described as being 15x25x5. there is also a footnote ref# ( 24, 96 ) I cant find out what that means.
Are these different grades or versions of the same seal? I looked at one at the dealer showed me. it had a hard black ceramic disc outboard (kinda like a washer incorporated into the seal) of the seal lip. This one was 20 bucks plus! for a 1" seal!
I wonder what one or the other looks like and if one of them costs like a "normal" (whatever that is) oil seal?

Thanks Guys, Dan.

 

[Fish]

If replacing the seal without splitting the case, use the #96380031581.

If taking the pan off, use the 96390031585

 

[Lakeside53]

The -85 seal is closer to $8.

The best sealer to use is the Dirko Red - that's what the factory used.

Why are you splitting the engine to change the saw case? It just comes out as a complete unit.

You might want to get a service manual.

 

[jbgariel]

I have used yamabond 4 with good results. It can be had at any yamaha shop.

 

[paddlerdan]

Calling all Stihl techs-

Any Ideas guys. Why the 2 part numbers (listed previously) for the same seal? I am still guessing that there is a stock and maybe a " heavy duty" seal.
Lake, If you recall my pressure testing/ no impulse question of about 2 weeks ago, I found out that the clutch side seal is faulty. That is why I am changing it.
Thanks for making me sit back and think though, as I fell into the misconception of the " plastic case" Stihl consumer saw BS that is going around. Looking at a photo of the case I thought I saw where the seal was pressed in. I knew better, that the power unit ( piston& cyl., rod,crank, main bearings,pan, etc) is bolted to this plastic "chassis" as a unit.
My current case is cracked to s*** and leaks bar oil.
Any how, ideas guys on why the 2 part numbers for the same seal? I am still guessing that there is a stock and maybe a " heavy duty" seal. I'm just curious. I going to take back this 20 dollar seal and get the cheaper one.
So to swap cases to a new one wont take any gaskets? Just some sealant as needed, if at all? Am I hearing this right?
Thanks, Dan.

 

[Fish]

Reread my post, 1 is for when you replace just the seal, the other if you
are replacing the seal when you have the case split. The one is easier to press in, I guess.
Why are you doing this anyway?

 

[Lakeside53]

No gaskets - just sealer...

Service manual???

 

[paddlerdan]

Got It!

OK, Fish, now I get it, it seems I got the "----85" seal, This is the one that presumably is for replacing while the case is not split, (what I need). I was wrong on the price of the seal I got it was $15 & change, with the inpulse hose and tax came to $20+.
I guess it has a stiffener around it. Kind of a black ceramic washer incorporated into the seal. It seems the dealer gave me the right one.
I'll post a pic later to explain.
First of all I have no/low impulse pressure, and found through a pressure test, a leaky seal.
While its apart I want to replace a cracked case. Oil tank leaks, someone did the JB weld thing but it still leaks overnight.
BTW, The case I was looking at fell thru, does anyone have a spare plastic case for an 021/023/025 or a MS 210, MS 230 or MS 250 for sale? They all will work.
I'm posting in the classifieds here too.
tx. Dan