Pin clearance?

[Workerbee]

I need to replace a couple bushings on a dozer. The originals are 1.965” diameter and need to be torched out as they will not come with 20 tons of pressure.
Now I can get new replacements for $480/pr at the same specs, or can get some that are quite close but the diameter is 1.961 for $185/pr.
Quality is equal, (same mfgr) what would you do? Will .004 extra clearance on a 2” pin cause issues?

 

[mcfarmall]

No. It's a dozer, not a Swiss watch.

 

[Daferris]

Back years ago when I was a machinist in the stamping press repair trade. The standard was .001 inch per inch of diameter. I would think that (I am assuming these are pins for the tracks). with a an extra .004" of slop they will wear quite fast as grit ect will have more room to enter the joints. They also will be pretty sloppy,

 

[Workerbee]

Theyre the pins for the angle cylinders on the blade

 

[Daferris]

Theyre the pins for the angle cylinders on the blade

In that case it will still be a " sloppy joint" but since you only would have a pin at each end the cumulative effect of the extra play would not be as bad. Given the price difference it's probably worth a try. I would grease them more often than normal just for the attempt to help keep grit out of the joint.

 

[Workerbee]

They get greased daily, but the machine doesnt get babied. It pushes a lot of stumps and levels rocky ground. Will the .004 take out bushings a lot faster or wear out the frame holes? I cant really see the frame holes being an issue, as like I said, we cant even push the old pins out. Theres nothing rusty there, its like the pins grew, or were assembled with a press.

 

[GreensvilleJay]

re: No. It's a dozer, not a Swiss watch.

have to agree.....kinda hard to believe you don't already have more than 4 thou 'slop', here, there, everywhere...... especially since its NOT a 'trailer queen'.

bushings will usually wear first

The old pins may be slightly 'egg' shaped. I'm betting you don't rotate the pins every time you grease them, so they get 'hit' on the same spot every time. eventually the circle becomes an oval (egged).

 

[lugbolt]

don't overthink it. Put bushings in, put it back to work.

 

[Workerbee]

Like you said, Its got play here and there, especially in the chains and pads. The 6 way blade pivot points have been pretty decent, but they do get a beating and eventually that adds up. Im leaning towards saving the money, but not if its going to just cause a premature failure. None of the repairs on dozers are easy or much fun.

 

[TheOldHokie]

I need to replace a couple bushings on a dozer. The originals are 1.965” diameter and need to be torched out as they will not come with 20 tons of pressure.
Now I can get new replacements for $480/pr at the same specs, or can get some that are quite close but the diameter is 1.961 for $185/pr.
Quality is equal, (same mfgr) what would you do? Will .004 extra clearance on a 2” pin cause issues?

You said bushings are 1.961/1.965 and the pin is 2". How does that work?

Dan

 

[PoTreeBoy]

If these are bushings, aren't the cheaper ones going to give a tighter fit?

 

[Daferris]

They get greased daily, but the machine doesnt get babied. It pushes a lot of stumps and levels rocky ground. Will the .004 take out bushings a lot faster or wear out the frame holes? I cant really see the frame holes being an issue, as like I said, we cant even push the old pins out. Theres nothing rusty there, its like the pins grew, or were assembled with a press.

 

[Workerbee]

Im not sure how you do things where youre from, but here the pins need to come out to replace the bushings, and they arent coming out without torching them out. Lol, saying 2” pin was in relation to the .004 clearance.

 

[Daferris]

It could be that they were put in cold and the that would also explain the tight fit. Likely what has happened is the pin has a wear step that is catching the bore. That would keep it from coming out potentially if not in exactly the right position. I don't think the bores will get hurt bad enough to make a difference with the smaller pins. The thing to watch/be concerned about is the contact area that the pin has in the bore. Then smaller pins will apply pressure to slightly less of the bore radius that it's going to contact on compression. But it's such a small difference that I don't think you have to worry about it. It's just something to be aware of/keep an eye on. When they start to get really sloppy again I would replace them as that's when you probably would start tearing up the bore.

 

[Workerbee]

It could be that they were put in cold and the that would also explain the tight fit. Likely what has happened is the pin has a wear step that is catching the bore. That would keep it from coming out potentially if not in exactly the right position. I don't think the bores will get hurt bad enough to make a difference with the smaller pins. The thing to watch/be concerned about is the contact area that the pin has in the bore. Then smaller pins will apply pressure to slightly less of the bore radius that it's going to contact on compression. But it's such a small difference that I don't think you have to worry about it. It's just something to be aware of/keep an eye on. When they start to get really sloppy again I would replace them as that's when you probably would start tearing up the bore.

Now that makes sense to me. Thank you
I apologize to Dan and Po boy for my poor wording in the original statement. I do need to replace the bushings but the pins need replacing also due to the fact they will be ruined getting them out.

 

[TheOldHokie]

It could be that they were put in cold and the that would also explain the tight fit. Likely what has happened is the pin has a wear step that is catching the bore. That would keep it from coming out potentially if not in exactly the right position. I don't think the bores will get hurt bad enough to make a difference with the smaller pins. The thing to watch/be concerned about is the contact area that the pin has in the bore. Then smaller pins will apply pressure to slightly less of the bore radius that it's going to contact on compression. But it's such a small difference that I don't think you have to worry about it. It's just something to be aware of/keep an eye on. When they start to get really sloppy again I would replace them as that's when you probably would start tearing up the bore.

If the pins are going to be destroyed size the new pins to fit the new bushings. Do you know the actual diameter of the new pins?

Dan

 

[Workerbee]

If the pins are going to be destroyed size the new pins to fit the new bushings. Do you know the actual diameter of the new pins?

Dan

I havnt bought the new pins yet but do have the new bushings.
The correct pins would be 1.965” diameter @ $209 ea plus tax and shipping. I can get pins that are 1.961” diameter @ $82 ea plus tax and shipping included. Both are OEM JD pins.
Thats why Im asking what the consequences of saving $250 can cost me before I order the pins.

 

[TheOldHokie]

I havnt bought the new pins yet but do have the new bushings.
The correct pins would be 1.965” diameter @ $209 ea plus tax and shipping. I can get pins that are 1.961” diameter @ $82 ea plus tax and shipping included. Both are OEM JD pins.
Thats why Im asking what the consequences of saving $250 can cost me before I order the pins.

I would spend the extra money.

I doubt .004 has any effect on rate of wear but if you start out undersize you will definitly hit the wear limit sooner.

Dan

 

[DustyRusty]

This machine is used every day to make you money, and I doubt that what you will save equals much more than a few days profit that the machine generates. The machine being down while you debate saving a few hundred dollars is costing you more than that few hundreds of dollars. Buy the correct parts, put it back together and put it back to work. You are pinching pennies and losing dollars in the meantime.

 

[Workerbee]

This machine is used every day to make you money, and I doubt that what you will save equals much more than a few days profit that the machine generates. The machine being down while you debate saving a few hundred dollars is costing you more than that few hundreds of dollars. Buy the correct parts, put it back together and put it back to work. You are pinching pennies and losing dollars in the meantime.

Actually its not used every day. We bought this long ago to do some development work on our own land and for our own use only. Its paid for itself in that regard. So time isnt of the esscense here, but I do know what you were thinking and if it was used every day you would have a valid point.