You could probably get a machine shop to fab it, it would be pretty straightforward to do out of 2 pieces that are then welded together...

 

Thanks Dave_R, I think that's a good suggestion. I'll check around to see if I can find a machine shop that's willing to work on it. I was thinking I might ask them to check out the housing bearing housing (? not sure the correct term) is square, if not possibly machining it to the next larger bearing size. The bearings pressed in very tight so housing may be okay, I think the big problem was I couldn't find the correct bushing that fits between the inner bearing races so I had to mostly guess how long to trim the one that I found. I'm guessing it was either too long or too short causing the bearings to wear quickly.

 

Yes, you want that center bushing to be slightly too long, so when the assembly is tightened, the outer race of the top bearing goes again the ridge of the machined spot for it in the housing, the inner races of the top and bottom races press against the center bushing, and the outer race of the bottom bearing "floating" in the machined spot for it in the housing (so it's not pressing against the ridge in the housing). From the spindles I've worked on, the bearings are just a close fit, not a press fit, so when the bore in the housing is cleaned, and with a new bearing, you can push it in/out by hand, but it doesn't rattle around.

 

Well it's interesting, the old races were stuck very tight despite the bearings being destroyed. It was very difficult to get the new ones in as well, used my press and it took a fair amount of pressure before they seated. I don't think there would have been metal transfer, the housing appears to be aluminium. You can see the old center bushing, it wasn't helpful for measurements. I'm pretty sure this is how they came out, completely dry and no grease in the housing at all, the other outer race was still stuck in the housing at this point.

 

You want to clean the housing so at least one of the bearings isn't a press fit, it has to be able to slide a bit on it's own as the spindle is being tightened. It's not unusual to have to use persuasion to get old bearings out, as rust and dirt can wedge them in place, but the new bearing (or even reinstalling the old one if it's good) has to be able to move a bit so that it doesn't have a side-load on it (due to the inner and outer races not being aligned).

And you probably should use something like a lathe or spend some time making the end's of the spacer bushing square, as if they aren't, the center race can be tilted a bit, also causing the bearing to wear faster.

 

..and you want the spacers to be the same length for all the spindles (unless they use a very odd setup), as typically with using a center spacer, the length of it affects the blade height.

 

where did you find a jackshaft? trying to find one