Got some excessive play in my swing frame to boom connection. Is this possibly a worn pin or would the bushings be wrecked? I have about .045 of lateral play at top pin and about .030 of vertical play, videos below. I think im missing the top shim which is supposed to be .020 as i see no space at all between the top forged ears of the swing frame and boom(red arrow in pic below)
Post a Serial Number please so someone can look up specs and any adjustments. A quick check showed 8 different models of 305E2. No telling if they are all the same or not.
Thanks, Its H5M10007
Most likely to be bushings but don't count on the pin having no wear at all. Maybe the pin could be slid part way out for inspection.? At least far enough to look at the surface of the pin where it rotates on the bush. I see that 0.020" thick spacer. So it's not there on your machine.? Never been there as far as you know.? The parts list calls for two of them in that location. There is a mountain of work and required tooling to remove the swing frame. Maybe a short-term fix would be to get hold of some 0.030" material and manufacture a shim for the top. If you can then raise the uppser pin far enough the shim could be slid into the space. TBH I would also manufacture a shim for the bottom of that same joint which looks as though it has far more daylight between the frame and the boom than the upper side does. If you can cut down the movement relatively easily you could then monitor the lateral movement going forward.
Thanks Nige. I cleaned things up better at the spot where there are supposed to be the .5 mm shims and there are no shims. Not sure I can make up some .030 shim stock, since i dont have a lathe and machine shops around here are sparce. Could i get the correct shims and put them in the top? Where there are supposed to be some? Wonder what happened? I bought the cat used with 1500 hrs, and noticed some play when i got it at 1500 hrs
Sure you could. Just that because you have a 0.030" (1.5 shim thickness) gap my thought was to get hold of some material of the appropriate thickness and custom make a shim to fit your specific circumstances. The shim is 92mm inside diameter and 133mm outside diameter. TBH with material only 0.030" thick you could almost make one using a 4" grinder equipped with a cutting disc if you had steady enough hands.
Ok so I put a jack under the bottom pin and jacked up taking up all slack, got .042 in feeler gauges in that top joint so those factory shims should be just about right. Also I pulled the pin and yes there is wear and the pin measures oval shape on the upper part of it. .010 measured with a caliper. I was surprised because that's a fixed no rotation part of the pin. so I guess I'll get a new pin and shims?
It will certainly improve things but I would bet that in order to fix the problem completely will need a replacement of the upper bush as well.
I replace the Pin and added the 2 shims that were supposed to be there and it cut my slop down by half or better.
I remachined one of these from a 305 and made a new, oversized, hardened 4140 pin to fit. This was a big job on my boring mill and really made me scratch my head why Cat built them this way. Not a great design, very cost intensive to fix.