Advise me on bearing removal and replacement on a harrow

[Arkaybee]

QUESTION FOR mjncad

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.

I see the end of the extension in the photos but I can't figure out how you made the extension. I am in real need to do the same on a metric machine. Is the extension solid pipe or flexible rubber tubing? It appears that there is a clamping device on the end of the tube to retain the zerk. Also, how is the extension attached at the machine end?

Could you please explain how you made the extension? I would greatly appreciate it and it would be helpful to me and others as well.

Thanks for your help.

Arkaybee

 

[mjncad]

Arkaybee:

I bought some 10mm x 7mm steel tubing from McMaster-Carr. I threaded each end with a die. One end goes in the factory hole, and the other end is for the jam nuts I used to insure I could orient the 90-degree Zerk the way I wanted it to be. The tube end with the Zerk was threaded with a standard 8mm tap. It just so happens that 7mm is the tap hole diameter for a 8mm thread size. If you are using a straight Zerk, the jam nuts are unnecessary.

I have a bunch of tubing left; what do you need? Maybe I can make you one if this tubing size is right for you. We can discuss price later.

I hope I described this clearly on how I made mine.

 

[HCJtractor]

I am still frustrated with the bearing removal. I have soaked it, cleaned all the debris around periphery, and heated it. It still has not moved the slightest, not even a microscopic amount. I will continue to soak it in PB Blaster and next time use more heat.

What is the possibility of cutting the bearing out with a plasma or torch? Sorta dissecting it carefully from the center outward? My whole project is at a standstill and the housings are too expensive to break. Could this be done, even enough to deform the outer rim so that it can be collapsed slightly to break it free? It appears that the fit is so snug that the bearing almost appears bigger than the opening in the housing.

I ordered a new housing so when it comes in, at least I can study the exact pathway of insertion and removal. But in the meantime, could a skilled operator cut it out? I have seven of these to do and I have spent several hours on one with no luck at all. Even if I could see a tiny bit of movement when I tap on it, I would be more optimistic.

 

[mjncad]

I've heard that an ATF-Acetone "home brew" mix of 50 - 50 automatic transmission fluid and acetone works better than any commercial product.

 

[Mace Canute]

Regarding the ATF/Acetone mixture...

Penetrating Oil ??? - The Home Shop Machinist & Machinist's Workshop Magazine's BBS

 

[Mace Canute]

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.

I have to ask...how did you manage to break that housing? How did you try to get the bearing to move and what did you use on it?

 

[mjncad]

Regarding the ATF/Acetone mixture...

Penetrating Oil ??? - The Home Shop Machinist & Machinist's Workshop Magazine's BBS

Thanks for the link to people who have tried this mixture first hand.

 

[HCJtractor]

I have to ask...how did you manage to break that housing? How did you try to get the bearing to move and what did you use on it?

Mace, I am embarrassed to tell you. After soaking and cleaning and trying to get it to move, I used my shop press to try to get it to rotate a little. You can say "you told me so" and I plead guilty. I learned my lesson about cast parts and how they can break. I worked on the other housing last night and finally after several hours, I got one bearing out with the housing intact. Man, they are really locked in tightly and it was a bear to get out. I think I have at least learned what works and what doesn't. I have 6 more to tackle. I still wonder if I can cut the internal aspect of the bearing with a plasma and perhaps make it a little more flexible to break free.

 

[timster2]

Here is an old trick I use to use to remove frozen bearing races from salt spreaders, similar bearing assembly. Using a torch cut out the bearing and roller cage parts until you are left with the race. I assume if you have a plasma and a torch you have a welder. Next weld a bead on the inside of the race, the heat of welding expands the race and the cooling of the bead shrinks the race and breaks the rust. When cooled the race will come out with finger pressure. In some cases they would fall out on there own.

 

[Arkaybee]

Thanks mjncad.

Your description is good; and thanks for the offer to help me out by making one for me. I will have to determine the thread size of the zerk I need to extend. The Kubota dealer says there are two different sizes of zerks used on this machine (ZD18 ZTR mower). This zerk goes to the base of the middle spindle housing and is behind the deck drive-belt and very difficult for me to get to. I want to extend with a pipe or hose and mount the end on or through a metal tab so it is out of the tight confines. I will let you know what I find out when I learn it. Thanks again for responding.

Arkaybee