Can you over grease lawnmower deck spindles?

grantiman

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I have an older Z-Force, model # 17AF3AGV010. I just replaced all 3 deck spindles and filled them full of grease until I felt pressure, put my blades backed on and tightened the nuts with an impact, my blades seem to turn hard now for some reason. My old spindles were shot and making noise, the bearing were going so I decided to replace all of them. With the old spindles on and the deck belt off, I could spin my blades very easily, with the new spindles on I tightened the blade and they seem to turn by hand very hard, did I pack to much grease inside them? I have always put my my blades on with the impact and could always move the blades with my fingers, when I tighten the blades on the new spindles, they're even hard to turn by hand, am I doing something wrong?
 

StarTech

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Well let's start with what did you torque the blades to. They are torque at 100-120 lbs. Over torquing will preload the taper bearings too much and cause binding (the bearing is suppose to prevent this but not always). Also did you install OEM spindles or aftermarket ones? I have had problem with aftermarket ones in the past. This is why I prefer to rebuild these taper bearing spindles.

Each spindle rebuild requires:
  • 2 Seals MTD 921-3018A (Rotary 12535)
  • 2 sets of LM11949/LM11910 Cone Bearing Set. MTD/Cub will sell them as separate pieces driving your costs up a lot more. (2ea MTD 941-04298 cone bearing and 2 ea MTD 941-04299 bearing cup). You can actually get these cone bearing set from your local auto parts store as they are use as trailer axle bearings.
What I have seen with aftermarket spindles is the bearing spacer being too short or too long. Both causes problems.
 

grantiman

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I'm not sure what the torque is, I don't have a torque wrench, just tightened them with an impact. It's a heavy duty impact and can deliver up to 750 ft lbs of torque, that may be the problem right there. I'll re tighten them with just a 1/2" socket wrench, I don't believe I'll go over a 100 lbs using that, just to see if they turn any easier. My replacements spindle are aftermarket, I was also thinking about maybe those spacers being to short. If they turn better just tightening with a hand wrench, I'll buy a torque wrench so I can tighten them correctly, I didn't know my impact had that much ft lb torque for tightening until I just read about it online, I'll keep you posted, thanks.
 

Joed756

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Often those spindles, even those with Zerk fittings, are assembled with sealed bearings. I can imagine too much grease pressing on a sealed bearing could maybe cause this. Have a look at the bearings, if they are sealed just remove the sealing piece from he inside of the bearing, this will also allow for constant bearing lubrication.
 

StarTech

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Joe have you dealt with tapered wheel bearings?

I have yet to see these bearings with self contained seals.
1717953910255.png
 

Joed756

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I have used tapered cone roller bearings, primarily on bicycles, but I don't believe I've seen them sealed.
 

jviews12

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Using an impact with 750 ft lbs is way overkill. I suspect it should be less than 125 lbs, but this is a guess. Impact great for taking off, but not putting on.
 

RevB

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I have an older Z-Force, model # 17AF3AGV010. I just replaced all 3 deck spindles and filled them full of grease until I felt pressure, put my blades backed on and tightened the nuts with an impact, my blades seem to turn hard now for some reason. My old spindles were shot and making noise, the bearing were going so I decided to replace all of them. With the old spindles on and the deck belt off, I could spin my blades very easily, with the new spindles on I tightened the blade and they seem to turn by hand very hard, did I pack to much grease inside them? I have always put my my blades on with the impact and could always move the blades with my fingers, when I tighten the blades on the new spindles, they're even hard to turn by hand, am I doing something wrong?
Too much grease can cause rolling elements to skid vice roll. Rolling elements require a vanishingly small amount of grease. This is the same reason more two stroke oil isn't better for two strokes' crankshaft bearings...the excess oil builds a hydrodynamic wedge ahead of the ball and the ball skids in the race instead of rolls. Needle bearing in con rods are very low speed and dont suffer the same fate.
 
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