Stihl 075 Complete Rebuild and Performance Mods

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The rewind housings were easily broken on the finned parts.These rewinds got swapped around a lot bak in the day.If a cutter had two Stihl 08ss in the bush one older one newer he would swap rewinds as nobody cared much what the saw looked like never mind the logo.Get them trees on the ground choke em up and skid em to the landing.Repeat cycle till dark.the recoil from the S10 or the cut off saw were identical.
Kash
 
Not to get sidetracked again, but for the sake of thread accuracy there were two different types of recoil assemblies and they were not interchangeable..., at least not easily. One was friction shoe. One was the pawl engagement. Different fanwheels were required for each. (There were even two types of flywheel friction cup inserts for the friction shoe design.) This applied to the TS's and other saws of the era as well. The newer style logo was used on both styles which could lead one to believe that a newer recoil was interchangeable with an old one based solely on the logo, but the different assemblies were not interchangeable without also changing the fanwheel and/or flywheel.
 
Not to get sidetracked again, but for the sake of thread accuracy there were two different types of recoil assemblies and they were not interchangeable..., at least not easily. One was friction shoe. One was the pawl engagement. Different fanwheels were required for each. (There were even two types of flywheel friction cup inserts for the friction shoe design.) This applied to the TS's and other saws of the era as well. The newer style logo was used on both styles which could lead one to believe that a newer recoil was interchangeable with an old one based solely on the logo, but the different assemblies were not interchangeable without also changing the fanwheel and/or flywheel.

Thanks for the input. I'll have to watch these type of issues as I put stuff back together.
 
Ok, we had a bit of weather here in Texas. Power was off and on for a few days and garage was freezing, so I haven't gotten anything done lately.

IMG_5280.jpg

On top of that, I got a box of junk from Oregon - some Stihl parts and two Jonsereds 80's that were completely wasted. Finished disassembling those and harvesting what little I could use off of them.

In the meantime, my eBay 075/076 case showed up. It's serial number 4354410 and it's in pretty good condition. Given the serial number re-start in 1977, I'm guessing this saw was produced in January 1978, give or take a month or two. That would put it 4 years later than the damaged case that I'm going to toss -- SN 8295359 -- June 1974. I compared the two and can only see minor differences from a visual comparison.

IMG_5322.jpg

I also got a shipment of NOS 1111 gaskets (2 complete sets) in from Australia. I think I paid about $45 each + shipping. Not cheap, but I certainly prefer this to aftermarket bits.

I'll split the cases on both saws tomorrow, harvest what I can from the damaged case halves, and start reassembly.
 
Ok, we had a bit of weather here in Texas. Power was off and on for a few days and garage was freezing, so I haven't gotten anything done lately.

View attachment 890956

On top of that, I got a box of junk from Oregon - some Stihl parts and two Jonsereds 80's that were completely wasted. Finished disassembling those and harvesting what little I could use off of them.

In the meantime, my eBay 075/076 case showed up. It's serial number 4354410 and it's in pretty good condition. Given the serial number re-start in 1977, I'm guessing this saw was produced in January 1978, give or take a month or two. That would put it 4 years later than the damaged case that I'm going to toss -- SN 8295359 -- June 1974. I compared the two and can only see minor differences from a visual comparison.

View attachment 890957

I also got a shipment of NOS 1111 gaskets (2 complete sets) in from Australia. I think I paid about $45 each + shipping. Not cheap, but I certainly prefer this to aftermarket bits.

I'll split the cases on both saws tomorrow, harvest what I can from the damaged case halves, and start reassembly.
Be sure to save that billet aluminum oiler button! I'm looking forward to seeing how this turns out!
 
Spent several hours on the saw this weekend and made some progress.

10 screws hold the case together. They have a regular flat tip screwdriver head. My preference would be an allen or torx, but I managed to get them out without stripping any of the heads. I also tapped out the two drive pins that align the case halves. I split both cases so I could harvest the useable bits from the original saw case.
IMG_5323.jpeg
From there, I split the case. The tool I use just barely fits inside the crankcase. You can also split the case by slowly prying it apart with something non-destructive (plastic pry tools), but that's a tedious process that can take hours.
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The cranks appeared to be the same. The one for the original saw was stamped "32 - 74" and the one from the eBay case was stamped "36-77". These should be date codes from when the cranks were produced. The 32 and the 36 could refer to the day of the year (32d day of 1974) or the week of the year (36th week of 1974) in which the the crank was made. Some of the bearings felt a little gritty at first, but after a good cleaning, they were all quite smooth.

IMG_5327.jpeg

Oil system for original saw (top) and eBay case (bottom) were quite similar. I went with the pieces from the eBay case.
IMG_5328.jpeg
 
The oiler bodies for these two saws were configured differently, as you can see in the picture. As a result, I suspect the case is machined differently, too, and the oilers won't mix and match. I didn't try swapping the oilers, so I could be wrong on this. The later model (from 1977 eBay case) has a part number of 91111547040.
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You'll need snap ring pliers to get a few snap rings out - one for a crankcase bearing and the other for the oil pump. Helps to have a seal puller to get the seals out, too, but you can also tap them out with a hammer and socket once the cases are split, of course.

IMG_5335.jpeg

Took quite some time to clean off decades of dirt, grease, and sawdust from the nook and crannies on the case but it cleaned up pretty good. This is a mechanical rebuild, not a cosmetic restoration, so I just give it a good cleaning; no painting at all.
IMG_5336.jpeg
 
Spent several hours on the saw this weekend and made some progress.

10 screws hold the case together. They have a regular flat tip screwdriver head. My preference would be an allen or torx, but I managed to get them out without stripping any of the heads. I also tapped out the two drive pins that align the case halves. I split both cases so I could harvest the useable bits from the original saw case.
View attachment 891314
From there, I split the case. The tool I use just barely fits inside the crankcase. You can also split the case by slowly prying it apart with something non-destructive (plastic pry tools), but that's a tedious process that can take hours.
View attachment 891315
The cranks appeared to be the same. The one for the original saw was stamped "32 - 74" and the one from the eBay case was stamped "36-77". These should be date codes from when the cranks were produced. The 32 and the 36 could refer to the day of the year (32d day of 1974) or the week of the year (36th week of 1974) in which the the crank was made. Some of the bearings felt a little gritty at first, but after a good cleaning, they were all quite smooth.

View attachment 891316

Oil system for original saw (top) and eBay case (bottom) were quite similar. I went with the pieces from the eBay case.
View attachment 891317
I agree with you on case bolts, Torx my choice,,,,, You need to get a dirtier hammer, that new Estwing makes you look a brand new mechanic . I can't trust you any more. LOL
 
I removed the bearings from the cases to give them a good cleaning and inspection. From there, the pair that were going back into the case were put in a plastic bag and tossed in the freezer; this reduces the OD just enough to make them easier to reinstall. Then I used a heat gun to heat up the case where the bearings sit to expand the case a bit. I was able to get the area up to 300* or close to it.
IMG_5342.jpeg
Tapped in easily afterwards and checked to make sure they still spin freely. Dribbled a bit of Stihl oil on them for good measure. Tapped the seals in using the same method - heat the case and freeze the seals. I added a dab of grease to the inner lip of the seal after installing it.
IMG_5337.jpeg
Next I installed the case gasket, held into place on one side with some Indian Head shellac.
IMG_5345.jpeg
Then I took the crank out of the freezer (again, slightly shrinks the OD) and installed it. I got it pretty close to being flush with some gentle tapping and then finished pulling together with the case screws.

IMG_5349.jpeg
 
Got the oil pump reinstalled next, followed by the sprocket and clutch assembly. Clutch shoes looked really nice with a lot of fiber left, so I re-used them. Sprocket is .404 rim drive, 7 pin.
IMG_5350.jpeg
Got ignition installed after work today and got the flywheel cleaned up and installed, too. I know there are compatibility issues with ignition components but since all these parts came off the same saw, I don't expect to have any issues.
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I'll set the flywheel gap next, and then probably install the jug and piston.
 
Got the oil pump reinstalled next, followed by the sprocket and clutch assembly. Clutch shoes looked really nice with a lot of fiber left, so I re-used them. Sprocket is .404 rim drive, 7 pin.
View attachment 891338
Got ignition installed after work today and got the flywheel cleaned up and installed, too. I know there are compatibility issues with ignition components but since all these parts came off the same saw, I don't expect to have any issues.
View attachment 891339
View attachment 891340
View attachment 891341
View attachment 891342

I'll set the flywheel gap next, and then probably install the jug and piston.
It had a 8 pin 3/8 rim on it when I got it, to work with the 28 inch bar, but I was gonna put the 41 on it so I swapped the rim. I'm happy to see it getting the care it deserves.
 
The oiler bodies for these two saws were configured differently, as you can see in the picture. As a result, I suspect the case is machined differently, too, and the oilers won't mix and match. I didn't try swapping the oilers, so I could be wrong on this. The later model (from 1977 eBay case) has a part number of 91111547040.

Case is indeed different, starting with serial number 9945250. Found the tech bulletin that details it. There are several other pages that describe the tools and process to modify the early case to accept the later oiler, too.1111 Oil Pump Rev.1.jpg
 
It had a 8 pin 3/8 rim on it when I got it, to work with the 28 inch bar, but I was gonna put the 41 on it so I swapped the rim. I'm happy to see it getting the care it deserves.

3/8 would work better for someone who is going to mill with it. When it's done, I'll likely offer it for sale with a choice of either 3/8 or 404.
 
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