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Discussion Starter #1
The local JD parts man says the the new spindles with grease fittings only grease the lower bearing. He says the upper bearing is sealed on both sides and the lower one is sealed on the outside. Why would this be the case? Why wouldn't you want to grease both upper and lower bearings. He told me I could buy all lower bearings and be able to grease both on each spindle. Is what he says true? Thanks for any input.
 

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Yes, he's correct. The bearings are the same size, but have different seal construction.

I rebuilt my old spindles on the L120 by drilling and tapping hole for a Zerk fitting. I then replaced both bearings with double sealed ones from McMaster-Carr and removed the inner seals on both top and bottom bearings. I grease them about three times a season. I just checked them after two seasons of use and they're as tight as new, so it WAS worth the effort.

However, I found it was NOT a good IDEA! While the system works well for wear, I now have minute spots of grease over the top of my deck over time. It's slung there as the grease works its way through the top bearing. It cleans up easily in the Fall cleanup, but the deck looks like it has measles during most of the summer.

Why did JD only make the bottom bearings open to grease? Probably because of the above "problem" and also because the lower bearing takes most of the strain. Just think of the stress applied by a slightly off balance blade spinning at a few thousand RPM. Anyway, that's just my guess.


Hope this helps,
Paul
 

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I've asked about that before. It's so if no one greases them the grease won't work it's way out of the upper bearing due to gravity. So basically it's so they will last longer if someone isn't greasing them.

BUT, if you grease the spindle, it will bypass the seals and enter the upper bearing. Tried it myself on a new one. When I filled it with grease, once full it to ooze out the top bearing upper seal - so it gets in there.

Paul's above answer is probably some of it too. When I've seen bad spindles, the upper bearing is usually OK. I think the grease mainly keeps water/condensation out, like on the old non-greasable JD spindles that lasted fine, but were packed with grease upon assembly.
 

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I did the same as ryanpf did. When I grease my spindles, I listen for the grease as it passes the seal. I stop as soon as I hear a sound like a pop or squeak sound. Really hard to describe in words. Just don't use a power greaser. Do it on a quiet day so that you can hear as you HAND PUMP the zirk. My 46" deck on my 318 has been working this way for years with no trouble. And I have had no spots on the deck or under it.:thThumbsU
 

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Discussion Starter #6
Well after I bought new BCA bearings with the plastic/rubber seals I started thinking about their ability to handle the stress of the blades. The original bearings are "PEER" and have metal seals. Are these good bearings or the cheapest thing that JD can find to use in the decks?

I would like to do it right while I have it apart. I am thinking about getting the original bottom bearings sealed on 1 side and using them on top and bottom so I can grease them both. I know I can remove one of the seals on each of the BCA bearings but am afraid I will blow the outside one off when I grease it. Will the metal seals blow off too?

I have packed many bearings over the years and I know it takes some pressure to push the grease into the bearing. Thanks for all the replies.
 

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When I first said what I said, I was referring to the bearings you can pick up at any local parts store. I was thinking about common bearings that have a metal shield covering most of the seal area. Then there is a very small area around the area that the shaft will penetrate through, namely the center most of the shield that has a rubber compound. Take a small screw driver, stick it through the rubber area and pop the seal out. Put the bearing(s) in the spindle so the shield is away from the grease zirk and be done with it. Now the hard part comes. After filling the cavity between the bearings, the grease starts building up pressure until finally grease starts ozzing out around the shaft where the rubber part of the shield is. It is at this point where you have filled the cavity that you should really slow down your pumping grease. Take a shot of grease, wait, another shot of grease, wait, etc, letting the preasure even out somewhat. When you just start to see the grease push the rubber seal ever so slightly away from the shaft. Then STOP.

We haven't gotten in to this, but after removing the blade,and hopefully sharpening it, I hope you make some attempt to balance it by removing metal from the heavy end. What you use to balance the blade is up to you and not part of this thread. But is a vital part of the total process.
 

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Discussion Starter #8 (Edited)
Thanks for the info Doug. I have already sharpened and BALANCED the blades. I am just trying to figure out which bearings to use. The JD store has the bearings with one metal side but like I said they are "PEER" brand. I bought BCA bearings which I think are as good as any. None of the parts stores had bearings with metal seals.

I went to several stores and the cheaper $5.00 bearings are already loose in the box. You can move the inner race side to side. I am pretty sure they WON"T get any tighter as they wear. I would rather have the metal seals to prevent blowing out when greasing. Are the JD "PEER" bearings made for mower decks? Or are they the cheapest thing they can buy to put in these decks?
 

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Are you replacing the non-greasable spindles with the new greasable ones or have you had a problem with the greasable ones? I only say this as most people here have no repeat problems out of the new spindles. And like I said earlier, grease WILL enter the top bearing when you grease the housing.

I think you are overthinking the bearing thing. I doubt there is any bearing specifically for mower decks.
 

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Discussion Starter #10
Are you replacing the non-greasable spindles with the new greasable ones or have you had a problem with the greasable ones? I only say this as most people here have no repeat problems out of the new spindles. And like I said earlier, grease WILL enter the top bearing when you grease the housing.

I think you are overthinking the bearing thing. I doubt there is any bearing specifically for mower decks.
I guess I am not stating my basic question clearly. I have drilled my housing and installed grease fittings. What I really want to know is would the good BCA bearing with the rubber seal/shield blow out of the bearing when pressurised with grease? Would I be better off using the bearings that JD sells with the metal seal/shield on the outside only? Thanks for all the replies.
 

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I must confess that in the 30 plus years of being in the work force, I have not used bearings with "loose" shields in all the gear boxes, electric motors, spindles, etc. that I have worked on prior to my retiring some 10 years ago. What changes to bearing design in the past 10 years I'm not priviliged to. So, I guess I must bow out of this thread. I would agree with Engine_Tech when he refered to the "overthinking" querry. I always used name brand bearings and never had loose shields.
 

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I don't think you'd have any problems with the BCA bearings. Old JD's never had grease fittings and had no problems. You just packed grease in the housing upon assembly to prevent condensation from forming. That water is what would kill the lower bearings. I think you will be fine. I don't think the grease being pumped in would damage the seals or blow them out.

You don't have much to lose, try them.
 

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Discussion Starter #13
I don't think you'd have any problems with the BCA bearings. Old JD's never had grease fittings and had no problems. You just packed grease in the housing upon assembly to prevent condensation from forming. That water is what would kill the lower bearings. I think you will be fine. I don't think the grease being pumped in would damage the seals or blow them out.

You don't have much to lose, try them.

Well, I drilled, tapped, and installed the grease fittings. I bought a new Lucas hand pump grease gun that uses 1 hand unlike the lever type that takes 2 hands. I also puts out less pressure. I installed the BCA bearings that I already bought and decided to leave the inner seals in place and just fill the spindle with grease to keep out the moisture as you suggested.

It took about 45 hand pumps each to fill the spindles because the hand pump gun puts out less grease than the lever type. Once I felt the slightest resistance I stopped.

Being the skeptic I am I decided to drop out each spindle shaft just to see if any grease had come through BOTH inner and outer seals in any of the spindles and guess what? It did! On the center spindle lower bearing it had actually pushed the outer seal out of the bearing! I was able to wipe away a little grease and pop it back in place. It went through the inner seal and blew out the outer seal. I guess that is why JD uses metal seals/shields.

I think I will be ok for a few years now, but next time I WILL buy bearings with metal seals/shields. Thank's to all of you for your help and advise.
 
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