Advise me on bearing removal and replacement on a harrow

[MHarryE]

Mace is right on that. The bearing in the spherical housing makes a great self aligning bearing unit much stronger than the stamped flange type found on so many lighter disks. When they are all rusted in place, however, they can be real tough to break loose. If you can't break them loose after soaking with penetrating oil, heat is your best friend. Put a bar through the bore for leverage to break them free, but remember what Mace said about too much force. You don't want to break a housing if you can possibly avoid it.

 

[mjncad]

There is also a 3" grease fitting extension that is broken. Where can these be bought?

By extension, I'm assuming you mean a tube with a standard Zerk at one end. I think you're out of luck buying them as I looked for a long time on the net for a 6" extension, and came up empty handed. I finally made my own as shown in the following photos.

https://picasaweb.google.com/110106108324823291002/FIMCOSprayer#5620098436918276610

The extension is partially covered by the "brake micro-switch for cruise control" text.

https://picasaweb.google.com/110106108324823291002/FIMCOSprayer#5620098428518596146

The extension is visible just to the right of the multicolored wire harness I added, and to the left and above of the master brake pedal.

 

[SandburRanch]

There is also a 3" grease fitting extension that is broken. Where can these be bought?

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Grease fittings with 1/8 th inch pipe threads are common so an eighth inch pipe nipple the length you need may be of some value.

 

[greasemonkeyok]

Soak the assembly for a week in a good rust dissolver. It can't hurt. I've used one of those "sonic" cleaning machines to speed up the process. The problem is finding a container large enough to hold the assembly.

 

[HCJtractor]

Bad night at the shop. Despite your warnings, I ended up breaking the cast housing! I tried to get it to budge and finally the housing snapped. I feared that my restoration project was over. But I called Athens Plow today and they still sell the housings so I consider this a $90.00 lesson. He gave me some advice also. Now that I can get a new one to inspect and have the old one to see what I am working against, maybe I will be more successful on the other seven. THe fellow at Athens said the tolerences are tight and that even a coat of paint inside the new one can make seating difficult. So the layer of rust and grime certainly locked it in. Next time, I will soak it longer, and try to pick out the dirt inside the housing with a dental pic. But being able to see the exact path of insertion and therefore the reverse path, maybe I can be more effective.

They still sell the zirk extensions, so I don't have to make new ones. And they are cheap.

 

[Canada_CT230]

As mentioned...heat the bearing block and the bearing should free up and should be able to be tapped out.

Heat is your friend here.

 

[MHarryE]

Here is a picture of a similar mounted bearing without all of the rust to give a better idea. This is a NTN bearing. At Allis-Chalmers/Deutz-Allis/AGCO and Case NH we always designed out own housing rather than buy an off the shelf unit from a bearing company because they wanted too much $$$. Athens is probably the same because they use a lot of 1 design and it is much better to design one to your exact needs rather than to make compromises to fit in an off the shelf unit. This unit has a groove around the center of the housing bore so it doesn't matter where the hole is in the bearing OD - grease is going to find its way inside.

 

[HCJtractor]

THe people at Athens advise mounting the block to a good strong metal table and (of course after soaking and cleaning) use a shaft the same size as the bore to leverage it gently. I will also use some heat. I assume I can heat it without fear. I am a rookie with a torch so should I heat it up moderately or all the way to red?

 

[kebo]

Don't think you want or need to get it glowing like a cherry. I think it will have expanded sufficiently before it gets to that point. As for soaking, I would just put them all in a bath of penetrating oil and let soak for a couple weeks, maybe even longer. Take them out every day to flip over so that any trapped air can release and let the fluid in a bit deeper on each side. Lastly, before you really start trying to pry them out, "shock" the bearings with some solid taps (but not too hard) on both sides. Use a piece of steel with a small, flat surface with the hammer, so as to not dent/deform the bearings like a small punch would. Good luck.

 

[MHarryE]

Remember you are trying to swell the housing oversize compared to the bearing so if you heat soak too much the bearing will start swelling too. Also if you concentrate the heat in one area too much you can also crack the housing due to stress. Just reminders, not dire warnings not to do it. Actually it sounds like a fun job. Instead I have this rusty old horse drawn disk with wood block bearings in cast housings I am trying to restore this winter, a rusty piece of junk I'd gladly swap for something newer and more practical than a lawn display in front of our place.