Hi guys, I blew my idler ram seal so I had to take the track off to fix it. But when I pulled the idler assembly off I saw the darndest thing: The idler wheel has been spinning on a raw axle all this time. No bearing. Is this how it should be? I am a real novice but I'm thinking no way Jose... You don't have to be a forensic scientist to see that the axle is badly worn away where the idler wheel has rubbed raw metal on metal. I'm thinking if I get a bearing put in I will not only preempt total disintegration but I will notice some extra power in my hitherto woefully unpowerful track drives. The digger is a crappy old 1970's 12 Ton JSW (JD/Hitachi precursor) that has already earned me its tiny purchase price in work done. I now feel ashamed I have been abusing this venerable machine so badly and want to make amends.... Can anyone tell me how to get the wheel off the axle? I'm assuming I have to undo the 4 bolts shown on the ram assembly in the photo above... any other tips? Thanks in advance, See my other posts for photos of the digger. Kiwi Ben
I'm afraid the proper procedure at this time is to replace the idler and axle, Sorry, Mitch
get an aftermarket unit idler axle and support blocks already assembled ill bet if you look the one on the oppisite side is probably bad also..
Thanks for the super quick responses guys... so are you saying there are not bearings on these things? Also, sorry to be stupid, but any advice on how to take it all apart?
there were bearings in there a long time ago, but it would be a very expensive undertaking to machine the parts back to size to put in new bearings. If the new aftermarket part comes w/ the side blocks, you just take out the 2 bolts on each side at the rear, and bolt the new one on
They have bushings with seals either side and filled with oil for lube, when the seals go they wear out pretty quick, i would have to say its done alot of tracking without any oil in there to end up looking like that the cost of repairing that would far out weigh the cost of buying a whole new complete unit Looks as though there would be a roll pin either side to locate the main shaft in the carrier, its abit hard to see how its held together but that would be my guess
Thanks guys, I'll hunt around for parts here in NZ...
Some more photographs... partly so you can wallow in my misfortune but mainly so I can steer my NZ parts dealers to the photographs and situation. But can any of you guys tell by looking at my "good" track whether the axle assembly has blown out in that one too too? It looks good and tight and straight to my untrained eye. Encouraging me further is the fact this good side has never thrown its track, Unlike the bad side.. I have had to put that track on 5 times now. One more thing: see in the second shot the track pin just left of the one I removed. It has fallen half out to the inside of the track. Do I just try and bash it back in? I already tried this with a claw hammer but it seemed impossible to line up properly and would go in. Is there a lug or something I need to line up? Here are couple of shots of the good side. Thanks in advance for any advice...
the pin should just hit back in, but it will be tight.. at least a 12lb sledge job but the hardest part is lining the hole up, good trick is to use a dummy pin (which is just a pin slightly smaller than a regular pin so it will fall into place) which you use to assemble the link with the seals in place and then drive the correct size pin home in turn knocking out the dummy pin you can make one from an old link pin by grinding it down to make it slip through the link with ease, my biggest worry with the pin which has walked out is that it is too loose and will keep doing the same thing and you may snap the chain or damage the link/s I've welded large washers on the outside of the pin (or links) to hold the pin in place to buy some more time for a track job before to check your other idler you need to take the weight off the track and get a large bar and lever the idler back and forth to see if there's any play, and finally i'm not surprised that you have lost the "bad" track afew times as the old idler was that worn it would have not been sitting straight when tracking or turning, as the side force moves the idler one way it would have been moving on a big enough angle to let the track slip off the the idler
Try these guys www.west-trak.co.nz
Awesome, thanks guys. will do asap
Love the corrugated iron on the roof mate, truly genius Cheers Wisey
Thanks Wisey... you should see some of my other fixes: galvanised pipe to replace a Hydraulic line, number 8 wire to hold the 2 main rams together to stop them from slipping off their pin top shaft.... But I am writing this post to report a stunning development. See photo 2 how the idler outermost edge has been pulled backwards by the track (thanks to the collapsed bearing)and therefore started wearing a groove in the idler yoke? (excuse me if I am using the wrong words). Well, that groove got all the way through the metal until it created a little pinhole through to the grease cavity o9f the track tensioner. Hence the catstrophic loss of track tension that I thought was a blown seal in the track tensioner. This was easily fixed with a blob of welding... I am pleased because a new adjuster was going to be $2000. Although I had plans to use a 10-ton hydraulic carjack welded into place instead Now for the new idler. This was impossible to source in NZ, so have bought a "near enough" idler for a komatsu p120. When it arrives I shall cut the arms of the old idler yoke to the appropriate size, and weld it onto the new komatsu idler arms. Bingo! This also means I won't have to try and get the roll pins out, which has so far proved impossible.... Will post photos of this latest Kiwi fix-up job when it's finished for your viewing pleasure. While I remember, Thanks to Mr Kobelco who has confirmed JSW turned into Koehring.... it was hard asking NZ parts suppliers to look for stuff when I didn't know what JSW had morphed into.
I ran a 450 John Deere with the same problem.The idler wore a hole in the grease cavity so the track would not stay adjusted.My fix was to put a tube of silicon caulking in an old grease gun and pump the track adjuster full with as much as I could get to stay in it but it didn't really work all that well because the silicon does not really cure very well in the absence of air so what I had hoped for did not materialize in practice. I jacked the idler forward and filled the cavity on a Friday night and it did hold for a while on Monday but hardly worth my time.We just welded tabs on the track frame to hold it and dealt with it the best that we could until it could be repaired. Now that I think back on it that is the last time that I ran the dozer,I found another job soon after.I put up with them for six or seven years.Ron G
well, no luck finding a new idler to fit. I bet there are plenty out there rusting away, but nobody can find one. I tried to fit a slightly larger new one but the extra inch diameter meant about 6 inches extra circumference and I couldn't rejoin the track even at the minimum adjustment. So I am going ahead with the rebuild. Looks like it'll cost me about the same as a new idler (US$600), maybe slightly less. Trouble is, I have no idea if the bearings I'm fitting will be strong enough or not.... I will just have to wait and see. Will post photos later of the fixit job.
Do you still have that other idler you bought? If you do, you can just cut the bearings and some of the sides out of it and get it welded into your old idler, that way you should be pretty sure the bearings will be good to hold the load and it probably will cost you nothing more than some welding time... At least that's what I would try...
Good idea... will do that next time if these bearings fail. So far so good... I have been throwing it round as bit to try and test the bearings and they are still working great. But with murphy's law they probably won't fail until I am in a precarious and remote location...