Hitachi EX75UR-5

[Muz]

The other track was loose but thats been tensioned (2 finger widths at under the most central roller)

The track which is the problem - Noticed it was sagging on the top side a fair bit, tried greasing it (obviously with track off the ground), and it wasn't taking any grease. Grease was escaping from the grease gun connector.
Picked the crap out of it, then used a ballpoint pen to exercise the ball bearing inside the grease nipple - tried again and i barely got 1/4 of a pump into it. (Had approx 4 to 5 finger widths of play on the bottom) Again, wasnt taking grease through the nipple.
It was when I walked on the top side of the track to start greasing the blade cylinder and rod ends that I noticed a lot of left and right wiggle in the idler carrier. It may be because of the amount of slack?
I have a photo of the position of the idler wheel prior to tensioning attempt on my phone but the forum doesnt support image uploading from mobile devices.

Just to be clear, the left side track is the issue.

Ok so it is purely that it wont take grease then, which is a different issue ... well that can only be two things, as you say the nipple is faulty, or the tensioner will not go out any further because it is either restricted somehow, or the piston is stuck in the cylinder. The restriction could be a binding issue inside the frame, as clearly its not meant to be out that far, or it could be impacted muck jamming it, so if its not the nipple you are still likely to be in for a shift .. cos you will need to pull the whole lot out and find out whats going on. This means slipping a track off (just at the idler .. dont take it off at the sprocket) and the whole idler and tensioner assembly pulled out for investigation, not the easiest on an 8 tonner, but dooable by a single human

[v8druid]

Probably hang on ... nah .. cant find it

IIRC not long after I joined Muz ... if you can search chronologically

[Locofitter]

The other track was loose but thats been tensioned (2 finger widths at under the most central roller)

The track which is the problem - Noticed it was sagging on the top side a fair bit, tried greasing it (obviously with track off the ground), and it wasn't taking any grease. Grease was escaping from the grease gun connector.
Picked the crap out of it, then used a ballpoint pen to exercise the ball bearing inside the grease nipple - tried again and i barely got 1/4 of a pump into it. (Had approx 4 to 5 finger widths of play on the bottom) Again, wasnt taking grease through the nipple.
It was when I walked on the top side of the track to start greasing the blade cylinder and rod ends that I noticed a lot of left and right wiggle in the idler carrier. It may be because of the amount of slack?
I have a photo of the position of the idler wheel prior to tensioning attempt on my phone but the forum doesnt support image uploading from mobile devices.

Just to be clear, the left side track is the issue.

[Muz]

IIRC Muz did a tensioner ram a while back with some piccies .... Muz .. am I right? can't recall where though?

Probably hang on ... nah .. cant find it

How would I get in back inside if this is the case? I'm assuming it'll be take the tension off the idler and push it back in towards the machine?
I dont think this is the case though as the track looked slack this morning before the work.

Now you are in for a shift ... to be absolutely certain , you say you pump it up (it takes grease) and it then goes slack ? overnight or something ?

[v8druid]

Anyone?

IIRC Muz did a tensioner ram a while back with some piccies .... Muz .. am I right? can't recall where though?

[Locofitter]

Anyone?

[Locofitter]

How would I get in back inside if this is the case? I'm assuming it'll be take the tension off the idler and push it back in towards the machine?
I dont think this is the case though as the track looked slack this morning before the work.

[Muz]

Managed to get the RH track tensioned properly, the LH is another matter. The idler carrier/wheel assy flaps about from left to right. I'm assuming this because the grease nipple is naff - doesnt seem to want to take any grease. So now on the hunt for grease nipples for it.

Just make sure you haven't pumped the piston out of its case, and the grease is just falling inside the carrier assembly which you can't see

[Locofitter]

Managed to get the RH track tensioned properly, the LH is another matter. The idler carrier/wheel assy flaps about from left to right. I'm assuming this because the grease nipple is naff - doesnt seem to want to take any grease. So now on the hunt for grease nipples for it.

Spent the day greasing all grease nipples, I dont think its seen grease in many years as it took approximately 10kg of grease across 20 or so nipples, shocking really, can already feel the difference in the controls. Arm ram should be ready for collection on Friday so should be fitted next week some time.

[Locofitter]

Indeed, I dont want to take a link out as its not the proper way and will only add wear in other areas such as carrier assy. But I dont think theres much choice in the matter.
I've never purchased track or track chains before so dont quite know which ones to buy, are they categorised by machine type? Are there different types etc? How do I know what to get a quote for?

I have seem two of the same machines on ebay for around £8,500 each and have requested it goes through to the committee that we purchase one and break it down for parts.

The joys of obsolescence!

[v8druid]

A similar discussion here


http://farmingforum.co.uk/forums/sho...-digger-tracks

I'm wondering if its because the sprocket only engages every second link, and/or if the sprocket teeth numbers are not equally divisible by the chain link numbers ?

As long as centre dimensions match Muz, the chain can be as long or short as you like ..... it's all about pin centres not track length .... if the track was just laid out on the floor, say a mile long, as long as the pin centres matched the sprocket engagement centres it'd just roll along the track .... it's why the system is called a track laying drive ...... just happens that they're endless on a machine ....... just a big rack and pinion drive ultimately.

[Muz]

How does it change the pitch Muz Pin centres remain the same .

Hmm ? just re-quoted a dealer of old, without thinking about it .. perhaps thats only relative to systems that had sprockets at either end like some old 803's I came across .. but .. if one sprocket was an idler it shouldn't ? got me thinking now as to what he meant, and I can see what you are saying. Clearly with a centre to centre difference in pins, the wear would be greater, perhaps he meant that taking a pad out just exacerbates that and causes faster wear because the pitch is even further out on an increasingly worn track?

A similar discussion here


http://farmingforum.co.uk/forums/sho...-digger-tracks

I'm wondering if its because the sprocket only engages every second link, and/or if the sprocket teeth numbers are not equally divisible by the chain link numbers ?

[Muz]

As a rule .. the further out the idler assembly appears from the frame the more wear it will exert on the frame that holds it,from a leverage point of view,as it is not properly supported, and it will give greater slap from side to side, leading to a much higher likeliehood of a throwm track, so either way, you shouldnt really be able to see the idler assembly. Cutting off a link just prolongs the inevitable, and is only a stop gap solution, but if funds are tight, it works for some, personally Ive never done it for the reasons mentioned earlier.

[Locofitter]

I've been given a brief report on the dipper ram: not looking good although it is repairable.
It appears that the rod had bent with the dipper fully extended, this had dug the piston into the barrel. Fine, BUT... The machine was used for an hour or so after this which in turn has caused quite severe gouging to the barrel walls. End cap was also bent and has had to be machined off.
Wouldn't mind going to the engineering firm to see them repair it, do like a bit of machining myself.

Muz, is it a safe assumption to say that its probably better to take a link out? Or shall I see how far out the carrier comes once track has been adjusted to its correct tension and then make a decision based on that? The safer option, I think, would be to take a link out as at least this would buy us some time to be able to try and source track chains with the metal/rubber shoes.
This Vesconite is a material far stronger and wear resistant than Nylon, as said before its going to be a long time before we put those bushes in but when we do, i'll most certainly update this thread.
If its of any other interest, i'll also update with the ongoing overhaul of said machine.

The manual is ok, one of the ones that came on CD from the states. However, its a bloody ball ache trying to go through it as all the pages are hidden in so many different file folders. Trying to make it so its a single, searchable .PDF atm. Not having much luck with that either at the moment.
Its nice to have the schematics though, not all too familiar with hydraulic diagrams so this shall be interesting.

[Muz]

Indeed, the idler carrier protrudes approx 20mm from the frame. Is this an acceptable wear limit and will adding a bit of tension to this track cause damage to the idler/track tension ram?

Its about as far out as Ive run any of mine, the piston for the tensioner will be quite far out of the cylinder at that point, but shouldnt bother it. The main issue with that level of wear is you are more likely to get tracks thrown off, so .. re bushing or re chaining reduces that likeliehood.

The last digger I owned with Nylon bushes (or similar) was a Hitachi EX8 ..micro .. and those bushes were crap IMO. I had no end of bother with it, and swore never to own another like it. I dont know if they just hadnt got the matarial right at that stage, but when you start getting site debris in about the system, it didnt seem to work. At least with greasers, you keep a constant pressure on the joint, pushing the shit outwards all the time.