I've ran across a few Dolmar 7300 series crankshafts in the that the past, that bearings were not loose, but would slide off the crank pretty much by hand. Then when I'd go to install the new bearings, I could slip them all the way home by hand.
From time to time I'll run into an aftermarket crank that has the same problem.
I thought about peening the crank with a point in several places, but that didn't sound like it would keep it uniformly centered.
I went to Harbor Freight and got one of those "el cheapo" engravers a while back, so I ran a random pattern over the bearings press fit surface Then the same surface treatment to the inside of
the bearing.![1484210750108-1492015654.jpg 1484210750108-1492015654.jpg](https://cdn.imagearchive.com/arboristsite/data/attachments/233/233925-87bcd09c31070dd19cc490a96e980496.jpg)
The microsopic divits did the trick. Maybe - like shot peening.![1484211117511-591311277.jpg 1484211117511-591311277.jpg](https://cdn.imagearchive.com/arboristsite/data/attachments/233/233926-da3cff100736443bda723d2bdd3b3d73.jpg)
For assurance, I put some loctite 638 on the mating surfaces, and pressed the bearing on.
It behaved just as a normaly clearanced press fit bearing.
If I ever get this saw back, then I'll report back on how it fared.
From time to time I'll run into an aftermarket crank that has the same problem.
I thought about peening the crank with a point in several places, but that didn't sound like it would keep it uniformly centered.
I went to Harbor Freight and got one of those "el cheapo" engravers a while back, so I ran a random pattern over the bearings press fit surface Then the same surface treatment to the inside of
the bearing.
![1484210750108-1492015654.jpg 1484210750108-1492015654.jpg](https://cdn.imagearchive.com/arboristsite/data/attachments/233/233925-87bcd09c31070dd19cc490a96e980496.jpg)
The microsopic divits did the trick. Maybe - like shot peening.
![1484211117511-591311277.jpg 1484211117511-591311277.jpg](https://cdn.imagearchive.com/arboristsite/data/attachments/233/233926-da3cff100736443bda723d2bdd3b3d73.jpg)
For assurance, I put some loctite 638 on the mating surfaces, and pressed the bearing on.
It behaved just as a normaly clearanced press fit bearing.
If I ever get this saw back, then I'll report back on how it fared.