I have a Cat 304C that has suddenly developed some bucket slop. A pin could have broken, but I’m looking at the various shims trying to figure out if something is missing. Starting with the tipping links. Should these be tight fore and aft, with no space between them and the stick? Here’s a vid of the movement...
And between the bucket ears and stick - how much space should there be? You can see 1/4” of space on the right side, and the left side has about 3/4” with a shim - should they fit tight or is. 1/4” reasonable? https://ibb.co/R6F03Gm https://ibb.co/NVk7nPc
Those links are definitely ovalled out and could use replacing or some welding. I like to go pretty tight with my shims on my cat 303. You would want to shim the bucket ears and stick as well. Does the thumb/end pin stick out like that normally or is it pushed through from the other side? Take some more pictures/videos
Someone needs to learn how to use a grease gun.
I should say that this machine is new to me so I'm trying to figure out what the previous owner was doing and where I need to give some attention. The thumb sticks out quite wide, and has some sleeves welded on to make up the gap to the stick. You can see both in the second pic. As for the bucket, it looks like the ears are a little wide and need some shims. One side has one that you can see from the pics, the other doesn't. Sounds like I need to add some shims in there so there is no space between any two parts. https://ibb.co/jfN0F92 https://ibb.co/BBhTqmq https://ibb.co/PFQb1Z2 https://ibb.co/CtjnqQy https://ibb.co/ykX5gbq https://ibb.co/grrYbRK
Someone cobbled together a bucket and thumb and made it work. Now you have some work to do to make up for their shade tree ways.
I wonder if the link plates on the side have or could have bushings installed? Doesn't appear there's a way to grease them.
The outside links are supposed to be locked to the pin and the pin rotates on the bushings inside the stick.
No doubt. That's alot of wear for a mini - those grease zerks must've never been hit with a gun.
grease ??????
Is that a crack?
Yes, it is a crack. It is only on one side but goes all the way across. Will have to give that one a new weld.
One side is locked to the pin, but the other side is not: https://ibb.co/16w0mTF https://ibb.co/mv04Q3q
I am planning to fill all excess spacing as close to tight as I can using spacers. The main bucket/thumb pin will be a bitch to align with all the weight. I may need to just pull the pin halfway and shim that one side so I dont have to take it all apart and fight to get it back together. As for the elongated link arm holes, the one side is bolted to the pin and is pretty tight - it is the other side in the video with a lot of slop. I plan to put the linkage in place with shims on pins, align everything then tack the washers in place. Not sure about filling the gap with weld however...
Yes don't take the pins all the way out just hammer them back so you can get a shim in at one point and do all your shimming there. Be prepared to play with the controls to line up the pin back but it shouldn't be too bad. try to get it relaxed on the ground i.e. turn the key to the on position and don't start it, put the hydraulic lockout down, and wiggle the controls to relieve the pressure in the lines and set the bucket down without keeping pressure on the pins.
Kind of makes you wonder about the rest of the previous owners "PM Maintenance Program" although that seems fairly obvious.
I pulled these off today. The issue is with the pins: they are worn where the link arms sit. The links themselves are a little elongated but the pins are the main issue. As for the bucket...the stick needs bushings and plenty of shims. I’ll start with the shims and tackle the bushings another time.
It sounds like everything is pretty worn out... You may want to disassemble everything around the bucket and make sure the bushings are still intact. If they are not you will start to wear into the bore that the bushing is in and make this a more expensive repair down the road (replacing pins and bushings vs line boring and replacing pins and bushings)
I’m in the process of replacing the bucket bushings and pins. The dogbone bushings came out fine. The bushings had some big pits in them and that pin had some lumps in it. The boom pin actually looks fine - minor wear but I’ll keep using that pin. But the previous owner had welded around each end of the bushing/bore. I ground off the weld protruding from the outer face of the bore, but I’m note sure how to get the bushing out now. I used a cutting disk on my Dremel to carve out around the outside of the bushing and into the OD of the bore a few millimeters. The only thing I can do is keep going deeper into the bore and expanding the diameter of what I’m grinding out until I think all the weld is gone before trying to pound it out. Here’s a picture of what I’m working with. Any thoughts/suggestions?
Those Bushings can be arc-aired out quite quickly, Then you can start with a good bore New bushings and new pin with proper grease holes and good for thosands of hours. A few more dollars now but if greased twice a day still new in 5 years from now. I always grease bucket linkage with bucket curled in at end of day and dumping also to get grease around full circumference of pins and bushings. No excuse for worn pins and bushings unless if excess hours. Thats how I see it. Simon
Well I don’t have an arc air so I need to do it the old fashioned way, somehow. The bushing actually has a split the entire length of it so it should be a snap to remove if I can expose the ends from the weld. Maybe a stone wheel to continue to grind out where I started, but deeper/wider? How far do I dare go?
Have you tried hammering/pressing it out yet? The welds make me think that the bushing was not properly fitted and you may be able to bust it right out. I would at least try that first before doing anymore grinding.
I had the very same idea - especially since the entire bushing has a full-length split. I've tried some pounding but have not seen any movement. The problem is I can't tell if there is weld still holding it in or not. I'm thinking I'll try using a grinding wheel to make sure the diameter of what I'm grinding is exactly the same as an old bushing and start hammering without grinding in any deeper. Any suggestions on what kind of grinding stone to use? I have been using a rotozip that's been working ok because of it's speed, but I need to find the right kind of stone for it.
If the bushing is split full length with arc-air or chamfer rod there will be way less external pressure holding it in the bore and whatever is left of weld or press fit tension may move easily with a hammer or maybe a hollow ram with puller plate and 30 tons of pressure. Should move with just a hammer if you split it again right through. If I was there i am sure i could split it in 1/2 hour or so. Simon
I like the confidence. You’re hired.
I was finally able to pound that bushing out after a bit more grinding. Next obstacle is getting new bushings in. It’s currently 30 degrees, I’m not planning to use dry ice. I plan to tap them in to get them started, insert a pin with a cap on it and pound them in as far as I can with a sledgehammer, then use an old bushing to recess them in the bore the rest of the way. One bore has a spacer bushing that sits in the middle of the bore between the outer bushings - that may be more of a challenge to get in. Anyone have a better ‘at-home’ process with minimal tools? Maybe just threaded rod to go through the bore/ new bushing with nuts/washers on either end to press them in?
Make sure bore is clean. Put small amount of 80/90 inside bore for lube, coat bushing. When you hit bushing in once straight and aligned do not use a small hammer as it will mushroom the drive end more. Use a big sledge on a quality driver or a Centre hole ram with push Plate and Power Pack. Frozen busing will help greatly. Simon
Great, thank you. I will keep the bushings in the freezer but it’s already well below freezing outside anyway. I’ll get it started with a small hammer and once started and aligned I’ll be using a big sledge, hitting an old pin that has a cap on it so there is a solid platform between the bushing and sledgehammer. Has anyone had success cranking bushings in just by using threaded rod going through the bushing and bore with washers/nuts on both ends?
If you are going to use a threaded rod weld a nut on the one end , so the rod does not turn if you put a socket and long power bar on the welded nut end. If the bore is not too tight cranking in with a puller rod works some time. You only have so much time with the frozen bushing. I is good to get the whole bore to maybe 150 Fahrenheit with propane torch or whatever , then put the lube in it , then quickly lube frozen bushing and install. Sometimes they go in very easily, sometimes way tighter. Hope this helps. Simon
Ive stripped out lots of threaded rods hoping it would work if you have someone tightening one side while you hammer the other, helps greatly. Also if you get a few cans of computer “dust off” air, you can hold the can upside and spray bushings with the liquid nitrogen. This keeps them nice and cold. Also if you have a welder, bottle jack and some steel you can weld up a rectangle and make a small homemade press to fit around the stick. Where there’s a will, there’s a way!
If you use a 1-3/8 National fine rod with lube on the Thread it will probably push the bushing in as Alaskaforby4 said especially if someone hits the back end with a sledge hammer.
Yeah a porto power makes the most sense but I don’t see you can rig it up without a hollow ram.
That is correct. Need a hollow 30-60 Ton Hollow ram. It is worth a try with quality ready rod with Sledge hammer behind. 12 Pound sledge is equal to 100 Ton Press with right man on sledge. That is my experience. Should have no problem with sledge and ready rod.
Id ask ,how are your bores ? Sounds like someones done some hack n slash by the looks of welded bushings. You might try and find someone with a set of mikes to measure the bore for out of round or taper. Were the bushings actually split when you opened things up?If so they must have been made up from something like light duty pillow block races . Airarc or a carefull trim with the torch is a simpleway to deal with the weld,you wont make things any worse with a bit of care. If the bushings are not split run a few beads of weld around the inside of them then you can tap them out after they cool. It sounds like you need buildup and lineboring or if the bores that small a new boss made and welded in.
I have all the bushings out. Bores are good.
Thats good ,always wonder when i see bushings welded in.