B21 - Replacing bushings

[PointyHairedBoss]

I am doing some repairs on my new-to-me B21. The stabilizer cylinder connections are a little sloppy so I decided to change the bushings - see the photo showing a worn bushing. Can anyone give me a tip for removing the old bushings? They seems to be siezed in there. I could go at it with a screwdriver or chisel but I dont want to score the bore of the cylinder.

 

[ihuntbear]

a press might work

 

[BruceWard]

I am curious how many hours your B21 has?

Would a bearing pusher and a press work? Something like this Bushing/Bearing Set

Or even a correctly sized socket, perhaps an extention and a press?

 

[PointyHairedBoss]

Thanks for the info, Bruce. My machine has 1700 hours.

I'm a rookie at equipment repairs but this will be a regularly used piece of equipment when we retire in the next 2 years. We will be in a remote location so I want to be able to do regular maintenance & small repairs myself so I don't have to rely on someone else.

I thought of using something to drive or press the bushing out but it is completely worn away on one side & there is no shoulder there for a punch or press to grab. I can work at it with an old screw driver or small chisel - I was just concerned with scratching the cylinder bore.

 

[leonz]

I am doing some repairs on my new-to-me B21. The stabilizer cylinder connections are a little sloppy so I decided to change the bushings - see the photo showing a worn bushing. Can anyone give me a tip for removing the old bushings? They seems to be siezed in there. I could go at it with a screwdriver or chisel but I dont want to score the bore of the cylinder.

Good Morning,


You have a couple of options, bearing/bushing drivers, a Dremel moto tool with long bits to weaken the bushing walls, a large CO2 fire extinguisher, and finally a sawzall which will work wonders; no worries about the bore as long as your slow in working and check your work every few seconds as it will advance quickly-2 cuts and its out- the steel in th ecylinder is harder than the bushing.


Throwing the new bushings in the freezer the night before or in dry ice will aid your repair nicely.

 

[SandburRanch]

I am doing some repairs on my new-to-me B21. The stabilizer cylinder connections are a little sloppy so I decided to change the bushings - see the photo showing a worn bushing. Can anyone give me a tip for removing the old bushings? They seems to be siezed in there. I could go at it with a screwdriver or chisel but I dont want to score the bore of the cylinder.

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I've cut bushings out like that with a hacksaw blade. Since it's worn through on one side you'll only need to make one cut on the opposite side like mentioned. A scratch or cut on the bore surface won't hurt a thing if you emery tape it a bit to prepare for the new bushing.

 

[PointyHairedBoss]

Thanks for all the help

 

[KWentling]

If its worn completely through on one side it shouldn't take much to drive it out. If you have a big punch, or maybe even use the old pin (I assume you are replacing it too) just use it as a punch and use a good 3 lb. or so hammer. You need to get "western" here. It will come. A screw driver is a pretty wimpy tool for this. A carpenters hammer likely won't be enough either. Leave it in your toolbox. It's likely the bushing (unless its brass) is hardened so cutting won't be easy. Is the new bushing a split spring steel or solid bushing? If its solid walled freezing will make it go in easier. If it is a split bushing, no need to freeze. Make sure you get all the rust and any dings you might raise in the bore cleaned up before going in with the new.

Kim

 

[BruceWard]

When I have replaced bearings in spindles I have heated the spindle in the oven and frozen the bearings in the freezer before installation.

I have also used brass drifts do drive things out. The brass is softer and deforms instead of deforming your project.

 

[KWentling]

When I have replaced bearings in spindles I have heated the spindle in the oven and frozen the bearings in the freezer before installation.

I have also used brass drifts do drive things out. The brass is softer and deforms instead of deforming your project.

I assume you are talking a spindle housing (hub). Freezing shrinks (liquid nitrogen is great), heating expands. If he heats the end of the cylinder he needs to extend the rod to get the piston seals away from the heat.

Agreed on the brass. If the bushing is hardened, it won't matter.

Kim

 

[PointyHairedBoss]

... Is the new bushing a split spring steel or solid bushing? ...Kim

Looks like brass - here is a photo from Messicks.

Now I have a related problem. I was unable to remove the cylinder end pin from either stabilizer arm. The cylinder referred to in my original post was disconnected by cutting the pin in 2 places with a sawzall. Two of the 3 pieces of pin came out easily bit the 3rd piece is still frozen into the frame - see 2nd photo. I used a sledge with a piece of 1/2 sch 40 steel pipe as a drift but it wouldn稚 budge. I even got a 3 ft. pipe wrench on the outside end of the pin in an attempt to turn it but no luck. Any suggestions?
(The 3rd photo shows the complete pin in the other stabilizer arm - frozen too).

 

[KWentling]

That may even be a fiberous composite. If it is, as I recall, they don't shrink when frozen. Your probably going to need a special driver to install those without messing them up.

As far as removing the end of the pin, if you have an ox/acetylene torch, you can try quickly heating the pin boss hoping that it will expand enough before the pin gets hot that it will get loose enough to drive out. If I had that where I work, I would get a port-a-power jack in between the ears, stout c-clamps supporting the ears so they don't spread, and jack it out. That might require heat too. I doubt you have access to the port-a-power though. If you have the above mentioned torch and #3 cutting tip you could probably cut it out.

Kim

 

[Carl_NH]

Along the lines that Kwentling mentioned you could get a 6" long 5/8" or 3/4" dia threaded bolt with nuts and flat washers on the opposite side of the cut pin and then turn the bolt pushing against the pin, then with some pressure on the pin, whack the head of the bolt to loosen then push/drive it out.

As mentioned before, heat, C-clamps to keep it from spreading and penetrating oil and you should be able to get it out.

For the other side if both ends are frozen thats a challenge but heat and some penetrating oil might be enough to loosen the pin..

Good Luck

 

[PointyHairedBoss]

... and penetrating oil ...

I thought of doing something with a bolt as you suggest but I have to get some heavy clamps first. Regarding penetrating oil, I thought that was mainly for loosening threaded parts. Will it really creep into seized up parts like I have?

 

[PointyHairedBoss]

I solved my pin problem:

1) cut with sawzall
2) heat with propane torch then penetrating oil when still hot
3) wait 2 hrs
4) compact hydraulic ram - about 4000 lb force - use clamp to limit frame deformation
5) apply my 5 lb gentle pursuader

Wow that was in there tight.

 

[irvingj]

Very nice documentation!

Were there really no grease fittings in that location?

 

[PointyHairedBoss]

Very nice documentation!

Were there really no grease fittings in that location?

There's a grease fitting in the end of the pin which feeds the center of the pin to lube the cylinder. But the pin is ungreased in the frame.

 

[KWentling]

That is exactly as I would have done it, right down to the exact same clamp and pancake jack! Good job.

Kim

 

[dfkrug]

I solved my pin problem:

1) cut with sawzall
....

Interesting you were able to cut those pins with the Sawzall. Kubota
uses hard/tough steel in their pins.

 

[PointyHairedBoss]

Interesting you were able to cut those pins with the Sawzall. Kubota
uses hard/tough steel in their pins.

They didn't seem that hard. I used a Milwaukee blade (Lennox is good too) & slowly rocked the saw as I cut. Through in less than 2 minutes. But after 4 cuts the blade is pretty much pooched.