CAT 225, drift or bleed down on the boom.

[fastline]

Sorry, the links are 9K6628 and 9K6629 (inner and outer?). There are some newer links that are 9K6629H and there are a few that are aftermarket. Asparco? or something like that but could not get a certain PN from them.

I know these chains have seen better days and frustrating because it really doesn't need to go far these days but if it can't track, that is an issue.

I have 2" of slack in the tracks right now between the top roller and idler.

I think the target pitch on these is supposed to be 6.75"

I am not sure what a reasonable wear limit is on the pitch but at this point, I am not sure where the issue is to determine what to do about it. I don't think it would be too wise to try to patch things too much rather than just replacing and I would be I will have my work cut out trying to press those pins. Well, some of them are literally steel bar stuck in there and welded!! There were running it around with bad lower rollers and grinding on them until they were VERY flat.

Is there a way to determine if the pins are very frozen to where lubing them could help for now? Tracks are so heavy that it makes assessing things difficult. I know when I jump on them, they seem to move pretty free.

Regarding the idlers, maybe I am wrong but I would think if that was the sort of my binding I would either see the track slip on the idler causing heavy marks or fresh meat where the idler was making contact with something?

When I look at how the pins ride the sprocket, they make contact with the front side of the tooth, then "pop" in steps down into the root of the tooth, then exit on the opposite side of the tooth.

As well, I read in another post where someone mentioned that binding and track issues can further cause final drive failures? Is this due to the extra load or something else?

 

[Nige]

If you have 47 links per track then Part Numbers 9K-6628/6629 are LH and RH links and correct for your machine. The specified link pitch is 6.75". To measure any pitch extension due to internal wear measure 4 links (pin #1 to pin #5 in other words and you should get a measurement of 27.00" when the links are new. A measurement of 27.50" is equivalent to 100% wear limit on pins & bushings, 27.70" is equivalent to 120% which is the scrap limit.

For link rail wear measure a few links from the underside of the track shoe to the bottom of the link where it runs over the rollers & idler using a straight edge across the link. New links measure 3.75", 100% worn 3.51", & 120% worn 3.45".

3V-1727 sprockets are original and correct for 6.75" track pitch.

In view of what you've posted regarding the "repairs" done to the links by previous owners it might pay you to look for a set of used links to which you can install your existing track shoes. If there is nothing available see if there is a low-hour option available from Cat. I'm not sure what they call it these days, maybe light duty or something like that. It's fairly obvious that the tracks have been patched at one or more instances in the past and that has brought you to what you have now. Continued patching-type repairs are only going to result in throwing good money after bad IMHO.

Regarding whether to lubricate or not, why not try it..? It shouldn't take a massive amount of time and even if it doesn't work you've lost nothing, but TBH if the machine was standing for 2+ years I would be very surprised if some track pin joints were not seized.

A complete new standard link group (2 reqd.) for your machine currently sells at $2,000.

 

[fastline]

OK, from your specs, it looks as though the chain pitch is not WAY out of spec and not even to max wear limit. I have provided a quick drawing of how the pins are striking the sprocket. When I tested the pitch, I measure over 6 pins to get a more accurate value. To obtain a 27.50" wear limit value, that is a pitch of 6.875" which, even accounting for some inaccuracy, I am certain I am not at. Due to that, I am wondering if I should do some repairs to the chain.

questions:
1. How can I determine if the pins are binding up? I know they move under force but not sure how to quantify an issue here?
2. if I obtain a few pins to replace the junk the other guy installed, will I have any luck with a big hammer approach to install? I will assume new interference fit will not be achieved.
3. Can you see the way the pins hit the sprocket as abnormal?

As I mention, when I hear the popping, it is most certainly coming from the sprocket area, not the idler or anywhere else. Each time it pops, you can see the pins stick/slipping their way into the root of the sprocket. They don't casually slide in.

I am also wondering about the bushing or pin wear that cannot be seen by testing the pitch? I think I was measuring the bushings at about 2.00" and I think new is 2.12"?

 

[etd66ss]

Not to hi-jack fastline's thread, but I too have a 225 51U26xx.

I have 7 frozen pin/bushings. 5 on the RH track, 2 on the LH. They were frozen when I bought the machine in 2009, and I thought when I used the machine they would free themselves up, they never did.

Here are some pics: http://i.imgur.com/nplmykL.jpg http://i.imgur.com/gOSW0nm.jpg http://i.imgur.com/17zyBbB.jpg http://i.imgur.com/WUhAt7n.jpg http://i.imgur.com/qxRK7pL.jpg

I have been using a mixture of diesel + used motor oil on just one seized pin/bushing to see if I could get them free. I put the entire weight of my Ford 575D backhoe on this joint and it didn't move. Next step will be to place a piece of firewood on the round and try to run it over in a way to back bend this link under the weight of the machine.

I dunno, so far, it doesn't seem like I'm going to get this to break free. These links have been seized for ~8 years now...

If I can't break them free with Diesel, is the only other option to field press the pins out?

What about drilling a hole in the top of the bushing to get oil/penetrant in between the pin & bushing then welding back up, taking care not to weld the pin to the bushing (even a small spot of weld would break free easily if I left the pin dirty)?

Also, about fastline's track popping. I too had terrible track popping on one side only for many years on my machine. It wasn't until one of the track drive hoses blew that the problem was fixed. I guess if you have a track drive hose that is leaking, the drive can surge generating a cab shaking pop. Ever since I replaced all the track drive hoses, I have never had any more popping when tracking.