Bounty Hunter
Addicted to ArboristSite
The last thread we posted we dealt with the condition of the cylinders and pistons of the dead 066 I am going to try to rebuild, and the dead 440 Mrs. Bounty Hunter has set herself to rebuild…come hell or high water. The 066 seemed to have perfectly fine bearings and seals, and it passed the vacuum and pressure test. The 440 did not…there was no point in even testing it since the bearing felt REALLY ROUGH…obviously hopelessly shot. We realized now why we got this saw so cheap.
So over the last few weeks we have been rounding up parts from our dealer and from one of the AS sponsors, Bailey’s…who provided us a gasket set, bearings, and new seals.
We had also obtained a Stihl 440 service and repair from FleaBay…20 bucks seemed a little steep but we now count it as well spent…as the manual has step-by-step pictures that even noobies like us can follow.
The first step in replacing bearings is splitting the cases…which according to the service manual requires a special tool…which we didn’t have. So, being the cheap hillbilly bikers we are, we made one. I took a heavy steel angle, tubing, and some threaded rod and nuts to make a facsimile of the Stihl tool. Here it is, ready to go…
It worked! We pushed the crankshaft right out of the bearing, then went out to the garage and used a shop press and a couple of appropriate sized sockets to pop the bearing out of the case half. For the flywheel side case half things didn’t go as well. We got some 5mm x 3” threaded rod and threaded them into the case half like the manual explains, but again didn’t have the special Stihl tool…but found a harmonic balancer puller for a Chevy engine would work. With some washers, the puller pushed the crank just right…but the bearing was so fried that all the ball bearings fell out of the races and the inner race stayed on the crankshaft. I had to grind it off with a mini-grinder.
After cleaning everything up, we prepared the new bearings, case halves and crankshaft for installation.
Here’s where we departed from the service manual…and leaned on the knowledge and experience of our friends here on ArboristSite…namely pioneerguy600, who wrote and outstanding description of how to install bearings and reassemble the cases…Thanks Pioneerguy600!
Here we go...the tools ready and the bearings are going in the oven set at 210 degrees…
Using welding gloves, we popped the bearings on the crankshaft…they didn’t just fall into place; we had to tap them on with a piece of ½” id water pipe. Here’s the crank with the bearings installed, so now we are ready for the bearings to be set in the cases.
The oil pump has to be in place to act as a stop for the clutch-side bearing, so we bolted it in temporarily. We then let the case half heat up in the oven for 5 minutes, then quickly set it on the wood blocks and tapped the bearing and crankshaft gently into place.
Now for the hard part…putting the cases back together! We threaded two of the 5mm x 3” threaded rods into the flywheel side case half to act as locating rods, as well as the existing Stihl pins. We set the gasket on the clutch case half, and blocked it up with the wood pieces. After heating the flywheel side for 5 minutes, we grabbed it out of the oven and popped it on…again it didn’t fall in place, but had to be tapped with a plastic hammer. The case bolts were used to draw it up the final bit…which (as Pioneerguy had predicted) caused some axial stress on the bearings and they did not move freely. We did a few baps with the plastic hammer to the shaft, and nothing happened. We lacked a brass hammer, but I had a chunk of brass bar about 5 pounds…two short biffs with the brass and that crank was centered and right as rain. We finished torquing the case bolts and installed the seals…
There it is! Mrs. Bounty Hunter is thrilled, as the rest of the rebuild should be fairly easy...Plus she just got her "Big Bore" kit from Bailey's...it's a 52mm piston and cylinder, which will up the cc's from 70 to about 78 I think...I've heard it makes great power in a 440...please stay tuned!
So over the last few weeks we have been rounding up parts from our dealer and from one of the AS sponsors, Bailey’s…who provided us a gasket set, bearings, and new seals.
We had also obtained a Stihl 440 service and repair from FleaBay…20 bucks seemed a little steep but we now count it as well spent…as the manual has step-by-step pictures that even noobies like us can follow.
The first step in replacing bearings is splitting the cases…which according to the service manual requires a special tool…which we didn’t have. So, being the cheap hillbilly bikers we are, we made one. I took a heavy steel angle, tubing, and some threaded rod and nuts to make a facsimile of the Stihl tool. Here it is, ready to go…
It worked! We pushed the crankshaft right out of the bearing, then went out to the garage and used a shop press and a couple of appropriate sized sockets to pop the bearing out of the case half. For the flywheel side case half things didn’t go as well. We got some 5mm x 3” threaded rod and threaded them into the case half like the manual explains, but again didn’t have the special Stihl tool…but found a harmonic balancer puller for a Chevy engine would work. With some washers, the puller pushed the crank just right…but the bearing was so fried that all the ball bearings fell out of the races and the inner race stayed on the crankshaft. I had to grind it off with a mini-grinder.
After cleaning everything up, we prepared the new bearings, case halves and crankshaft for installation.
Here’s where we departed from the service manual…and leaned on the knowledge and experience of our friends here on ArboristSite…namely pioneerguy600, who wrote and outstanding description of how to install bearings and reassemble the cases…Thanks Pioneerguy600!
Here we go...the tools ready and the bearings are going in the oven set at 210 degrees…
Using welding gloves, we popped the bearings on the crankshaft…they didn’t just fall into place; we had to tap them on with a piece of ½” id water pipe. Here’s the crank with the bearings installed, so now we are ready for the bearings to be set in the cases.
The oil pump has to be in place to act as a stop for the clutch-side bearing, so we bolted it in temporarily. We then let the case half heat up in the oven for 5 minutes, then quickly set it on the wood blocks and tapped the bearing and crankshaft gently into place.
Now for the hard part…putting the cases back together! We threaded two of the 5mm x 3” threaded rods into the flywheel side case half to act as locating rods, as well as the existing Stihl pins. We set the gasket on the clutch case half, and blocked it up with the wood pieces. After heating the flywheel side for 5 minutes, we grabbed it out of the oven and popped it on…again it didn’t fall in place, but had to be tapped with a plastic hammer. The case bolts were used to draw it up the final bit…which (as Pioneerguy had predicted) caused some axial stress on the bearings and they did not move freely. We did a few baps with the plastic hammer to the shaft, and nothing happened. We lacked a brass hammer, but I had a chunk of brass bar about 5 pounds…two short biffs with the brass and that crank was centered and right as rain. We finished torquing the case bolts and installed the seals…
There it is! Mrs. Bounty Hunter is thrilled, as the rest of the rebuild should be fairly easy...Plus she just got her "Big Bore" kit from Bailey's...it's a 52mm piston and cylinder, which will up the cc's from 70 to about 78 I think...I've heard it makes great power in a 440...please stay tuned!
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