Bearings loose in crankcase (93 XR600)

I have the cases split to replace second and third gears. Much to my surprise, the right side crank bearing fell out :thumbsup: while I was scrapping off the old gaskets. With the exception of the left side balancer and right side main transmission shaft bearings, all of them were loose. I was able to remove the crankshaft from the left side with a little pulling.

Are my cases screwed? For all these bearings, the manual has procedures to press them out and in. I can see how the bearings that are in the aluminum can get loose, but the crank bearings already are in steel sleeves. All of the bearings are in great shape. There is no evidence that the bearings were spinning in their holes. How did they end up loose? Overheating?

My plan is to do some intentional damage to the holes and then press the bearings back in. Is this a bad plan?

Any suggestions will be appreciated.

I just rebuilt my 96 Xr and had the same thing. I sent the crank and bearings to Xr's only and they said to reuse them. Seamed kind of questionable to me to, especially when the service manual is instructing to heat one piece and freeze the other to get the bearing in.

I have rebuilt several XR600 engines that exhibited the same thing, bearings were a snug fit, no pressing required, never had a problem. As long as there is no evidence of galling on any of the mating surfaces, should be OK. The one thing that you might want to consider replacing is the bearing plate, I have seen a few that allowed too much crankshaft end play and had to be replaced.

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