Drive work necessitated loosening the track. Grease fitting block on one side is at an angle pointed more downward than squared to the framed opening. I was able to loosen the relief to do what was needed, but was a bit tight in trying to get a socket on to the relief bolt. After the track was loose, I tried to move the housing/block with a slight pressure, no luck twisting it to realign it with the opening. I have looked in the parts book but cannot identify what keeps it aligned with the access opening? The track is presently separated, so if there is a bit more to it - to adjust the position of the grease fitting and relief bolt, seems now would be the time. Guessing it may be something very simple? Or should I say hoping it is? What do I need to do to turn the "grease housing/sleeve/block??" up for better access through the opening? The "grease housing" is a square configuration on this machine. Do I need to remove the idler assembly out of the slides to adjust this??
Assuming this unit will simply turn with no pressure on it???
Try moving the idler forward slightly. Easier than it sounds when everything's rusted.
Nige, Does the parts book show a pair of dowel pins that the adjuster head locates on? Seems like I remember some excavators built that way.
I don't see anything. It appears to me as though the opposite end of the track adjuster to the idler has a "dimple" (for want of a better word) on it, said dimple fits into a hole in the front end of the track frame and that is what keeps everything centred with respect to the track frame centreline. I assume that the fit of the dimple into the hole in the track frame is quite close and would bet that the 2 pieces are in fact rusted together.
i think this tensioner is bolted to the plate. i have done a 325D not long ago and that one was bolted on the end plate too. that tensioner looks a lot like this one. but it looks like there is some space between the end plate and the tensioner on this one tho. if this is a tensioner bolted on the frontwheel, then you probely need to jank it out there if it has so much rust and sand in it. then you can clean it out a bit and put it back again. sometimes its hard to turn these tensioners when even when the grease is depresurized.
It isn't - at least not according to the parts book it isn't......see post #5 above. If by "frontwheel" you mean the idler wheel then yes the front end of the tensioner cylinder assembly is bolted to the back end of the idler frame.....
Oke then just pull the idler out(in dutch we call it frontwheel) and clean it and get it back in.
Just grabbed up a seal kit for the tensioner, seems now is the time to pull the idler and assembly out of the frame and re seal it. I will take some additional pics and post when I get back to working on this machine. The other side idler needed replacing within the past year or so when the new chain and sprockets were replaced. The side I am working on was fine, I just noticed the tensioner block was turned downward in working through my final drive repair work. There was no issue with it keeping the track tight, but due to having the track separated at this point, might as well get after that it seems now too. Thanks for the replies on this subject.
Nige, do you have drawings that might help me see clearly how to get to and repack the track tensioner on a cate 311b Cat says the serial number is 8gro1237. what is printed on the machine is, 8Hro1237. Thanks so much Stacy Whetzell [email protected]
Finally getting back to this part of the project. Final drive back together and on the machine, seems to roll well unloaded. Pulled the idler and assembly out of the machine last evening. Nige was exactly correct in that a raised dimple is on the back of this housing with no bolting involved. The adjuster rod is simply stuck in the track adjusting cylinder. Not having much luck of removing the grease adjusting rod(?) from the mating cylinder as of yet. Pumped it up with grease, hung it, tried persuading it a bit with 12 lb sledge, pulled the fittings and tried a bit more persuading.... Any tricks someone might share? The rod pictured is a spare one..
For getting the piston out i usely put my hydraulic press on it with max700 bar. And if that doesnt work i weld the tensioner on the floor (got a steel plate in the floor) and pull it also with a crane. With or without also the 700 bar off pressure. How ever the tensioner i usely get are separate from the springpackage so easier to weld and handle. If that doesnt work then i throw it in the bin and buy a new one. Cause then usely the tensioner is so rough that its beyond repairs anyways. Good luck, it can be a pain to get it out!
Ahhh,, Good to read that it is not just my iron that this happens with... I actually thought it would slide out fairly easily, being it was a greased part. Thanks for the reply and info. Any considerations for re assembly that could be handy? - that is, when I do get it apart.
Ahhh,, Good to read that it is not just my iron that this happens with... I actually thought it would slide out fairly easily, being it was a greased part. Thanks for the reply and info. Any considerations for re assembly that could be handy? - that is, when I do get it apart.
Haha nope. **** happens to everybody. Usely the tensionerpiston will get rough by all the rust and when you push the piston back(to get the chain untensioned) then it eats the seals or atleast jams its self pretty tight. Goodluck
To install i usely put some bodyweight on it and lightly tap it with a hammer. So the seals can find his way. If you have a lot off rust on the rod it self just clean it up with some sandpaper so the sharp edges are gone. The tensioner is to cheap to think about re-chroming it again. So just make it round and smooth as good as you can and it probely will hold for a long time.
I like to slide the dust seal on the piston first then install the grease seals and backing rings. I then install the piston into the bore which takes a fair bit of pushing. Last thing I do is slide the dust seal into its bore in the cylinder and work it into place by carefully tapping around the edge with a blunt punch of some sort until it is seated. That way you don't have to fight the oring past the dust seal and pop it in the bore at the same time. There is probably a better way and I would love to hear it!
That sound pretty good too indeed. Might give that a try to next time.
What a bear of a job getting this one out was. Chained the whole idler unit back into the idler slot and pulled with the bucket, pumped grease to it, porta power in there, and had to pound the heck out of it all at the same time... finally began to move, but what a process, 1/16th at a time...... maybe... It did not look scored up or the like upon inspection.. Anyway,, it is out and now on to cleaning it up and resealing it. Idler wheel seal started leaking in the process, so now I'll be looking at what that takes to change those out... Onto the next thing.... How do you get oil into those? I did not see anything obvious in the way of a plug? Perhaps during assembly of the guides and brackets?
The idler is filled with oil during assembly. There is no way of draining/refilling oil without dismantling and you really don't want to be doing that. How much oil leaked out..? It's probably just a bit leaked past the seal while you were pulling on the tensioner.
Good Morning Nige, Guessing an ounce or so leaked out. It was not leaking prior so, you are correct for sure in that me tugging on the tension-er and handling the unit caused my leakage. How much oil is actually in there? I have not seen a print to know what makes up that assembly.. "Assuming" its a bushing / verse two roller bearings? I would hate to put it together and have the wheel seize up down the road.. Maybe it would be fine? Dis assembly instructions / procedure ? Thanks
Before you think of disassembly, read this .......... HeavyEquipmentForums The idler has a bronze bush inside it then the oil is retained by a steel duo-cone (face-type) seal on each side. The supports are pressed/frozen on to the axle. The seals have a tendency to leak if disturbed, or sometimes even if they sit for a long period of time without moving. TBH I would put it all back together and run the machine keeping an eye on the idler for any more sign of leakage. Most likely the leaking seal will "bed in" again and that will be the end of the problem. Fingers crossed.
I second Nige opinion, Its not to difficult to replace the seals but if you take them apart you better put new ones in. And even then its not 100sure it will stay good cause of some rust etc in the seal bed. Just work with it and see if it keeps leaking, usely they spring back in there happy spot and stop leaking.
Nige & BuMach.. Thank you for the insight on this issue. Sounds good to me, put it back together and monitor it. Nice link with good info regarding the 311 b that Stacy owns and that repair. My tension er piston looks a bit rougher than the spare one I have, quite allot of the chrome plating is missing as noted once cleaned up today. The missing overlay is fairly close to the internal o - rings and backers. With new UC on this machine, could probably get away with it as it would not effect the sleeve end cap seal for likely the rest of its lifetime with the rate i would be using it. Will re assess the spare one I have, but seems with minimal overlay missing that will likely be the choice for reassembly.
As long as the inside off the tube is still in desent shape you're good to go. (Otherwise grind it out or how you call it in english? Same as you do with cilinders and cilindersleeves) It would be nice if the chrome was still on the piston but that is only to keep the dirt out, and like you sad you're not running it as much and probely don't rely on it that heavy then your good to go. Just smooth the piston out a bit so your scraperseal doesnt get cut up. Good luck
BuMach, we would say "Hone".
Haha then its the same in dutch..
Good Morning, cleaned up the cylinder with a hone, looked decent inside, the piston slides in and out with no hitch or binding at this point. Should be assembling tonight if the rain holds out. Attached a couple of pics of the pistons with the guide bracket on it. Cleaned up the guide tracks and where the piston contacts inside against the frame. Interestingly, the end of the piston has a raised face (round) and can be seen in the photos. I anticipated that there was a matching hole in the pocket for it to guide into that would keep it centered up. That is not the case, it simply contacts a flat surface in there. The attached brace on the bottom of the piston is the guide to keep it lined up and aligned with the access hole in the side of the undercarriage frame. Should be very simple when reinstalling. New seals, lube it up and should be good to go.