My question is why was the heat gun focused on the bearing?
I was heating up the inner race of the bearing to install the crank. This is my first time reassembling a split case chainsaw, so please forgive my ignorance. After watching a some videos and reading a bit about it, I thought I had formulated a method that would work with the tools I have available. Here's what I did step by step.
1. Heat the outside of both case halves with heat gun and install bearings. This part went smooth and the bearings dropped right in with no issue.
2. Heat inner race of clutch side bearing and drop the crank in. This part also went smooth and the crank dropped right in and seated flush.
3. Heat inner race of flywheel side bearing and drop the crank (with other half of the case) in and seal it up.
#3 is where I ran into a lot of problems. I assumed that since the clutch side went in so smoothly, that the flywheel would be the same, but that wasn't the case. When I went to drop in the flywheel side it started to go but quickly got stuck. I applied a fair amount of force to it as well, but I ended up having to heat the outside of the case on the flywheel side and tap the crank/bearing out, then use my puller to get it back off the crank. I had plans to try this again using a press for more force, and equal application of it, but I haven't made it back to that point yet. Could this method have possibly worked had I put the crank and other case half in the freezer?
I decided to give it another try yesterday, but this time using the press. When I tried to reinstall the bearing into the flywheel side of the case using the same method as before, it started, but got stuck, so I tapped it out and tried to install it again, this time I decided to try that part with the press. I felt like I was having to apply too much force this way, so I decided to go back to the drawing board before I ended up breaking a case half or something. This is the part that really has me confused. Why would the bearings drop right in with 0 force during the first installation, but give me trouble on the 2nd go around? According to my chinaman laser thermometer the case half was right around the same temp as before.
To make matters worse, I decided to put a thin layer of Threebond on the mating surface of both case halves along with the gasket for some extra insurance. So I had to clean all that crap off, and make another gasket after my initial failed assembly. I don't know about you guys, but I really hate having to do that. lol
So now here I sit with an assembled clutch side case half, with the crank installed. Along with a flywheel side case half, and an overheated bearing, trying to figure out where I went wrong. I am open to any and all suggestions.