My Volvo ec240b is showing a bit of slop in the bucket pin. At only 2900 hrs, it seems a bit soon. But she has run a 2.25 yd bucket and a hydraulic thumb her whole life. I figure its the price you pay. I was wondering how much of a job is it to swap those bushings. Maybe i should get at it before it gets bad. Ken
It is a pretty good job. The bushings are very tight. You will have to weld them out and freeze the bushings to get them back in. What type thumb are you running? If it is not installed right it will wear very fast. I have found this to be a cause several times lately.
Weld them out? Can you elaborate please? I installed the thumb myself, and i am afraid it might be a bit tight. When i retract it, i can see the pin lifting slightly just before the thumb cylinder bottoms out. They told me to make sure the cylinder doesn't quit bottom out to prevent banging the cylinder repeatedly. But this means the pin and bushing takes the cylinder pull on retraction. Not sure what's best here. Thanks Ken
If you remove the pin and weld a bead the length of the bushing, the welding process with pull the bushing to a smaller diameter. Just turn down the output on the welder so that you don't weld the bushing in place. You'll need a press to install the new bushing. Dry ice or liquid nitrogen from your local AI guy will contract the diameter of the new bushing making it easier to press into place. I'm sure someone else here can offer a better description of the process.
Yair . . . watglen. What joispoi mentions is pretty right only I weld a good weave at pretty high amps right around the inside of the bush . . . it depends on the thickness of course. As joispoi mentions you don't want to weld it in! It's always best to do this last thing before knock off and let it cool down over night. Next morning you can often bump them out with the hammer handle, works like magic . . . usualy Alternativly if you are good with an oxy torch or even a hacksaw you just need to split that bush. I always had a couple of feet of 3/4" and 11/4" high tensile Acme thread and nuts which with suitable washers and pipe spacers was invaluable for extracting and installing bushes. The dry ice works and even over night in an ordinary domestic freezer will make a difference when installing. Cheers.
It takes quite a bit of weld to get them to contract enough to come out easily. You will want to weld beads to cover the whole bushing. dont worry about weld quality just quantity. The set i put in last month was about .004 -.005" tight. If you can freeze the bushings in dry ice before you start welding and then knock the old out. The stick will still be hot and expanded and will make install a little easier. You may still have to press them in.
I've worked on some bushings that have bronze or some kind of alloy in them, don't take welding well at all, welding helped little in contracting the bushing. On those type of bushings I've always had to melt a groove in the bushing with gas ax to make a relief to relax bushing. The biggest PITA to doing arm bushings at bucket pin and pin in dog bone is all the grease in there. You pretty much have to clean out all the grease or you wind up with a helluva fire.
Volvo uses a steel bushing. Yes it will mak a nice fire. The fire sometimes will help to heat the stic to ease installation.