12-09-2015 01:33 AM
Just an update on this, it did work, twice thus far. I figured since I had a spare cover to be rebuilt and swapped that I would do the remaining two engines (one was just recently swung so im not worried about it) the first engine has a little over a week's runtime on the rebuilt cover and the second engine has about 6 hours runtime on it and no failures yet lol. Now ill have the cover rebuilt one more time and put it back on the idle compressor package at the shop. Thanks and I hope everyone had a good thanksgiving!
11-25-2015 11:40 AM
11-25-2015 10:22 AM
Well, I am not totally sure about the clearances. I just went over the component measurements and did the math, applying the clearances that are used in other gear bushing/shaft setups like this in gear trains. For instance, some of the gears in the G3500 gear train are like this. There were so many replacement bushings that had too much clearance that Cat quit selling the replacement bushing and sold only the gear with the bushing installed. Many times after the customer had installed the bushing, it was too small for the shaft. When the machining was done, the clearance was too loose and that caused problems.
Hope it works okay. Let me know. Have a good Thanksgiving!
11-25-2015 12:38 AM
11-09-2015 10:01 PM
This type of operation is not uncommon. They want to have the tightest tolerance so they work on general dimensions and then want to shoot for a tight clearance when machined in place and assembled. This is common with bushings in timing gears to get a tighter, more uniform running clearance for longevity.
11-09-2015 09:21 PM
I didn't find any clearance measurements. But doing some rough calculations and referencing some similar shaft and bushing drives, I would shoot for machining the installed bushings to give 0.0095"-0.0105" clearance, (larger than shaft diameter). I would also shoot for 0.8 micrometer finish of the bushing bore when machining. Because there are no real clearances that I find, I might shoot for 0.005" to 0.008" clearance for first target to make sure you don't oversize machine the bushing bore. It also states that the shaft must turn freely in the TWO bushings when assembled. This is a pressure lubed bushing so you can stand to be a slightly bit tighter, I think.
A good machinist can take this info and probaby make it work okay for you.
11-09-2015 05:02 PM
Hello everyone, one of my 3608 A3's has a leaking alternator drive due to worn out bushings around the shaft and I would like to rebuild it. I have procured another used drive cover from our bone yard and have pressed in new bushings and have a new shaft, seal and wear sleeve for the pulley. The problem is I cant find clearance specs for the bushings anywhere in my service manual or the specifications guide. Wagner Cat the local dealer provided me with drawings that contain dimensions of the bushing and shaft but it doesnt give clearnaces of the bushings installed. The new bushings will slip right over the new shaft out of the box but when they get pressed into the drive cover the shaft will no longer fit into them. The part number for the drive cover assembly is 196-6044, the shaft part number is 130-5199, and the bushing part number is 130-5194. Any help would be appreciated Thanks!
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