Hilbilly
Veteran Member
I have to agree with Dave.
Bearings using an eccentric locking collar have runout built into them which is why they aren't used on things that require precision, no vibration or that run high speed. You can use an indicator to check how much runout there is but it wouldn't surprise me the manufacturer will say that runout is within their design limits.
Also, the input shaft may run truer when a load is put on it. I can't see the input shaft bearing in the video but I would imagine they used a self aligning bearing, probably a pillow block with an eccentric locking collar, that will self align once a load is put on it. Keep in mind that self aligning doesn't mean it will run perfectly true, it just means it will run true enough for the intended use.
OK, that's 2 votes for it's not something to be concerned about. Today I will run it up to PTO speed and see if it starts to shake badly. If not then I suspect it will be OK. I did indicate the shafts last night and this is what I found:
1) the shaft in the gearbox is dead straight and runs true,
2) the end of the fan, at a point as close to the rear as I could measure had 0.025" runout
3) the fan side of the chain coupler, as close to the chain as I could measure, had 0.055" runout
4) the driveshaft on the tractor side of the chain coupler had 0.060" runout.
I watched a video of the previous blower running and could not see any wobble on that driveshaft but that blower had a much more serious problem as I described earlier. Not the same thing as this one. This one appears to have the bevel gears properly shimmed, as there is no detectable slop and they look to be meshing properly. The only thing, so far, is the shaft wobble. However I can't use it to see if everything else is OK until we get some snow.
I have very little doubt in my mind that the manufacturer would tell me this is within acceptable limits, even if there is no spec for what that should be. I believe I found some information on what misalignment tolerances are within a roller chain coupler operating limits and will see if I can find that again. If this is within those limits and the wobble doesn't cause the whole thing to shake badly, at operating speed, then I guess it should be OK.