Replaced spindles/bearing assemblies; now she SHAKES

[longirons]

Have you tried removing the blades THEN running it ??

Have not. Good idea. Will do so the next chance I have to attack it again.

 

[longirons]

What happens when you put on the old blades? Do the new blades "nestle" perfectly when stacked together, and look identical ?

New blades nest perfectly. Old blades are gone, I'm afraid, chucked in the trash (maybe prematurely).

The runout required for good balance may be the problem. I believe you said 1/64" or .015" (check me). Seems like only a couple thousandths are expected at a bearing shaft.

Well, I said "less than 1/64," which it is. Maybe just the few thou expected. However, that was measured with a pair of uncalibrated eyes. I'll do a proper runout measurement the next chance I get.

 

[motoman]

Just more blabber on bearings...I once hit a brick with a front wheel drive car. Then a balance problem started. The wheels were rebalanced-still a problem. You could not feel any looseness jacked with weight off wheel , no runout. Finally replaced the hub and bearing-solved. Today I read a similar story in one of the auto mags. A typical new bearing assembly problem is the operator pushes the bearing in on the inner race and damages the balls which start working on the race. Or the ball separators become buggered and drop into the mix. Often cannot feel gritty sensation when bad. I bought a cheap HF stethoscope when I had a another front end problem. The thing uses batteries to amplify noise. The old way...put one end of a screw driver on the suspect and the other end on your ear while you rotate the shaft.

 

[SeniorCitizen]

Today I read a similar story in one of the auto mags. A typical new bearing assembly problem is the operator pushes the bearing in on the inner race and damages the balls which start working on the race.

The same thing happens on mower bearings to professional mechanics and DIY'ers alike when pushing on the outer races with a spacer between the two bearings unless one bearing is a hand push fit.

 

[longirons]

Well, it's been along, long time, but I thought I'd report back that the problem is solved, but I have no idea why.

I used the Murray several times this year, racking up about 10 hours over the warm months, with no change. Still shaking. A few weeks back, I was doing my last cut of the year. Everything was already brown, and I was mostly just smoothing down the top of the grass. There were a few drifts of leaves in the back yard that I didn't feel like raking, so I drove over them with the mower. On the second pile (pretty deep, maybe 8-10"), the mower bogged, shook even harder than normal, there was a bump/bang from the deck, and -- poof -- the shake disappeared.

I got off and under to see if I could see anything obviously changed, but, whatever it was, it was invisible to me. Cranked back up and ran it for another half hour or so. Smooth as silk.

:confused3:

 

[Boobala]

Well, it's been along, long time, but I thought I'd report back that the problem is solved, but I have no idea why.

I used the Murray several times this year, racking up about 10 hours over the warm months, with no change. Still shaking. A few weeks back, I was doing my last cut of the year. Everything was already brown, and I was mostly just smoothing down the top of the grass. There were a few drifts of leaves in the back yard that I didn't feel like raking, so I drove over them with the mower. On the second pile (pretty deep, maybe 8-10"), the mower bogged, shook even harder than normal, there was a bump/bang from the deck, and -- poof -- the shake disappeared.

I got off and under to see if I could see anything obviously changed, but, whatever it was, it was invisible to me. Cranked back up and ran it for another half hour or so. Smooth as silk.

:confused3:

Better bag up some leaves and keep em handy, in case there's "a next-time" ...:laughing:..:laughing:

 

[motoman]

Something hidden from your view dislodged removing the imbalance (chunk of limb)?