642 engine rebuild

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ryanu

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Sep 30, 2007
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New to the site. Great site. Very much needed! I am currently having my ford 1.6 rebuilt out of my 642.. While I am waiting I am poking around for other needed repairs. One thing I found was at the top of the lift arms there is a lot of back and forth play at the pivot pin, probably 1/8 inch each way. Does anyone know what is normal for play here? I want to put in some shims. Anyone else who has had to do this? Also, does anyone know of a good aftermarket parts place, or online Bobcat parts?
 

Tazza

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Do you mean back and forth or side to side play? You can make nylon shims to remove the side to side play but you will need new pins for back and forth movement. The arms andrams unfortunatly don't have re-newable bushings. When they wear all you can do is replace the pin and live with the slop. When i re-built my 743 i made it so i could pull new bushings in when they wear. 1/8” is really not mush at all i personally would feel thats an acceptable amount of play.
The pins are easy to make, get some quality precision ground 1 1/4“ bar and drill a hole in the end for the bolt to pass through. I use 4140 steel for mine, they are super tough even when they have not been heat treated.
 

ryanu

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Sep 30, 2007
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Do you mean back and forth or side to side play? You can make nylon shims to remove the side to side play but you will need new pins for back and forth movement. The arms andrams unfortunatly don't have re-newable bushings. When they wear all you can do is replace the pin and live with the slop. When i re-built my 743 i made it so i could pull new bushings in when they wear. 1/8” is really not mush at all i personally would feel thats an acceptable amount of play.
The pins are easy to make, get some quality precision ground 1 1/4“ bar and drill a hole in the end for the bolt to pass through. I use 4140 steel for mine, they are super tough even when they have not been heat treated.
It is side to side. I think it is too much because you can hear it bang back and forth sometimes. It almost appears that the frame is bent out slightly on each side of the pin. Maybe I worked her too hard! Are new pins pretty expensive that you recommend making them?
 

sterlclan

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May 1, 2004
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It is side to side. I think it is too much because you can hear it bang back and forth sometimes. It almost appears that the frame is bent out slightly on each side of the pin. Maybe I worked her too hard! Are new pins pretty expensive that you recommend making them?
ive run machines with less than 200 hrs that had/have more play than that if you keep em greased it shouldn't be too bad Jeff
 

Tazza

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ive run machines with less than 200 hrs that had/have more play than that if you keep em greased it shouldn't be too bad Jeff
I honestly don't know what genuine pins cost, but the 4140 precision ground bar i used was about AUD $25 per metre. I'm pretty sure they would be a fair amount more than that from Bobcat. The other reason was i changed how the pins were fitted to my machine so i had to make my own.
I'd shim the arms, you can use nylon cut to length in a lathe or you can simply use large washers. The less movement you have the less dirt is able to get in and cause wear. Don't knock the old pin straight out either, use the new pin (if you replace it) to knock it through, the arms with a bobtach attached are quite heavy!. This way the arm will not drop making it even harder to install the pin.
 

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