Hi Guys, We've noticed a leak underneath the sprocket and have cut the track. There was a simple 8 bolt plate that we removed and now this is where we are stuck at. Underneath the plate there are 4 smaller threaded holes between the other holes, however they seem to be rusted/stripped a bit. Any suggestions of how to remove the sprocket from the splined shaft inside? Our thoughts are to tap the smaller holes and to drive bolts in that should press against the sprocket behind it in order to remove the inner steel which holds the sprocket in place by wedging with the spline. Also maybe apply some heat to the spline to see if it loosens it up a bit. Thoughts? Mark
Something weird somewhere. The arrangement show in the manual does not show the circular plate. Also it shows the sprocket fixing to the adapter with 12 bolts, not 8. What's the Serial Number prefix..? What's the Part Number cast into the LH side of the sprocket in the upper photo..? Was there a single bolt with a large washer and an O-ring under it in the hole in the centre of the shaft..? Does that circular plate in the photos actually come off..? According to what I see the sprocket is fixed to the adapter with the bolts, so it should just come off given a good whack with the sledgehammer (making sure you support it first). After removing the sprocket you come to an internally-splined adapter underneath it that fits on to the externally-splined shaft (the one with the single large bolt hole in your photo). To remove the adapter from the shaft calls for 2 threaded rods screwed into 2 of the bolt holes in the adapter, a bridge over the top of those 2 rods, and a hydraulic cylinder from there to the end of the shaft to remove the adapter. Be prepared - It could be pretty tight ...........
The outer plate is visible to the left in the top pic , there was a large bolt with an O ring just under the head of the bolt, that screws into the splined shaft. There are 2 plates the mentioned cover plate with 8 holes. The plate in pic #2 has 4 smaller holes that are threaded between 5/8 and 3/4 maybe 11/16 or 18 mm but are not drilled into the sprocket. The adapter plate has the splines and not the sprocket. We put 2 sockets into the void near the shaft and tried to screw the outer plate back on in a puller like fashion. Also a large KD 3 jaw puller, a 12 lb sledge, and a little heat. She is not going to give up without a fight. Ser # 9YB02855 The 8 bolt holes are threaded into the sprocket only, the other 4 need a little chasing. I have a 10t porta power.
Don't mean to crash your thread, but the 8V4734 sprocket updates to the arrangement you have now. Nige, check out SEPD0186. Back over to you....
Found it .......!! It's actually from a 215C excavator of 4HG prefix. Maybe yours has had a complete final drive installed from another machine at some time. The "ring" in the photos with the 4 threaded and 8 plain holes is actually an adapter fixed on the splines of the shaft. The outer diameter of the adapter is tapered, as is the inner diameter of the sprocket. The way to loosen (note loosen, not remove) the sprocket on the adapter is to put 4 of the 8 securing bolts that you previously removed into the 4 threaded holes in the adapter and put some weight on them. (You hope) the sprocket will move inwards slightly on the taper and so will reduce the "crush" between the adapter and the splined shaft. Additionally you could drive maybe 4 or more tapered steel wedges into the small gap (marked "A" on the photo below) that exists between the sprocket and the flange of the adapter, your photo doesn't quite show how big that gap is, if any. You may also have to persuade the sprocket to move by using some heat on it towards the centre, but not too much or you'll damage the seals underneath. Once you have separated the adapter and sprocket you'll need a hydraulic puller attached to the 4 tapped holes in the adapter to pull the adapter from the shaft. The sprocket will then just fall off. I would suggest you run a decent tap through the holes first, according to the Parts Manual the thread of the 4 holes is 3/4" UNC but don't take that as read. Be sure to check the thread before you run a tap right through them and bugger the threads completely.
You are indeed correct sir. I also found a Service Mag SEPD0018 entitled Check Bolt Torque On Excavators Equipped With Collar-type Sprocket Assemblies relating to the correct procedure to check the torque of the 8 bolts 100 operating hours after rebuild and how to re-align the sprocket with the hub if necessary. I quote .......... Measure dimension (A) at several locations between the sprocket hub and the collar flange. The variation between readings should be no more than 1.0 mm (.04"). A uniform space is required. Loosen all eight sprocket-to-collar bolts. Use a heel bar to straighten the sprocket/collar to achieve a uniform gap. Good luck with that idea ...............
Another thought. Get hold of some good-quality anti-seize compound - copper-based would be good, moly-based would be even better. Lash loads of it on both the threads of each forcing bolt and also on the end of the bolt where it will come into contact with the sprocket.
There's also a service letter PS0344. They may have been replaced under that. I don't have access to SIMS to check.
present gap less than .010
That rules out wedges then. Forcing bolts, plus anti-seize compound plus a bit of heat and maybe a few strategic blows on the sprocket with an FBH then .........
Guys, I have an idea that may help, particularly if used in conjunction with the bolts. Do you know how to remove a tie rod end without the proper tool? You strike both sides of the tapered jacket holding the tie rod. Deforming the shape by of the taper by micromeasurements makes it pop loose. Perhaps the same principle will apply here. Of course, that sproket is too big to "deform" with a hammer. Perhaps if you heated the sproket in a wedge shaped or triangular pattern in one or two spots, it would expand enough in a non-uniform manner to come loose. I think the key will be to apply the heat all the way from the teeth of the sproket (wide side triangle) to the taper (point of triangle). You want to keep the tapered / splined flange as cool as you can during this process, so a can of penetrating oil will be handy (remove the flame before you spray the oil!!) Just a thought. Good luck.
The 215 rims that I have worked on needed pulling off the spline hub just like an early style sprocket, the kit needed to hook behind the rim through the sprocket holes in 3 places was a bit costly so I made some feet using big bolts and steel plate to make a clevis end,plus some flat strip to jamb the cut down bolts in the holes, I still have the pieces but never use them now as none of my customers have 215's, the feet that go to the service press (70 ton) hook through the holes in the sprocket being jambed in place with the flat bar, I dont think they are pressed on to hard as the 1's that I worked on came off at fairley low tonnage around 40ish, so a welder 3 big bolts and a few bits of steel 3 legs and a service press cylinder will soon set them free.
Tony, As far as I can see looking through the Service Manuals on-line there are 3 distinct types of sprocket used on 215s. I've never personally worked on any of them - all I'm doing is pulling the info out of the system. 1. On early models (e.g. 14Z prefix/3204 engine or 96L prefix/3304 engine) the sprocket bolts straight on an adapter that is part of the final drive. Hang a sling on the sprocket, remove 12 bolts and she's off but it then needs a pair of studs, a cross-beam, & a cylinder to get the adapter off the shaft. This arrangement seems to go right though all the S/N prefixes until the 215B comes along. 2. Later models are what you're describing. A single bolt in the centre, remove that and attach a 3-legged puller to holes in the sprocket then pull the whole thing off in one fell swoop. These were the sprockets where Cat made available a ring gear that could be welded on to the original sprocket (after cutting off the old teeth) obviously to keep costs down. 3. The final change the factory went back to a 2-piece setup but with the externally-tapered adapter shown in the diagram above. From what I can see the adapter is held on to the splines not just by the single bolt in the centre but also by the crush generated by the taper in the inside of the sprocket up against the taper on the outside of the adapter. This type of sprocket apparently needs first to be loosened on the taper by using 4 forcing bolts, then the adapter is pulled off the shaft using the 2 studs, cross-beam, & cylinder as previously. Once the adapter is off the shaft the sprocket then falls off. I am of the opinion that if someone tried to pull that sprocket using the holes in it it would actually tighten the adapter on the splines of the shaft and make it really hard to come off.
Nige, I have not done 1 of these bangers for years, but the way it fired free was by hooking and jambing " 3 fitments " that located through the outer large sprocket holes being pulled off just like pulling a D4D style spocket, I think I pushed off the undone a bit centre bolt? it might have been on a 219 or 225?? but I still have the home made fittings that I fab'd up to strip it down with, they are in my heap of things that I will never need again??? but WD40 heat and a big hammer is only going to do damage, it needs tearing off from the outside I am sure the sprocket set free off the hub without to much trouble, I dont think I have any photos of this else I would post them.
The 4 bolts holes in the adapter plate are 3/4" UNC
I can find out the part No of the hook adapters that fit in the holes of the sprocket if needed?? but thats how you tug them off with the centre bolt and washer loose to catch the bits after the service ram has done its duty.
I can find out the part No of the hook adapters that fit in the holes of the sprocket if needed?? but thats how you tug them off with the centre bolt and washer loose to catch the bits after the service ram has done its duty, the 3/4 unc bolt holes might be of use to tug against via a hard bar and a small hight cylinder pushing against the loose centre bolt with the washer still on to catch things?? but I never used this method.
Tony, this is what you're talking about I assume..? "Tooling A" is the following: - 2 of each 5F9306 Arm, 7B2499 Ring, & 5P2421 Adapter. 1 of each 5P3100 Pump, 9S8900 Cylinder Group, 6H4158 Pin, 2P8348 Adapter, 5F9882 Adapter, 5F9888 Adapter, & 5F9892 Adapter. There is another procedure for earlier machine but all it describes Tooling A as is in that case is "a suitable puller" .... not much use.
Nige, that tool a in your second pic is a posi-lock brand puller, they work great. I have some fairly recent experience w/ a 215c, and I know cat updated to that outside hub type sprocket for all the 215s, and nobody makes the solid sprocket anymore. BTW, cat no longer sells the conversion kit for older machines, you have to buy the parts individually, and boy, is it pricey. My thought is that you were right to start with, on that design, you must move the sprocket in first, as it does come up on a split-taper hub. A direct pull did work on both of the older designs, (except the solid sprocket I was working on, where the hub broke out and had to be torched off). Cat went to this new design about '90 or so, so I am sure that 215B was converted in the field.
Mitch, thanks for your confirmation of what I was thinking. I was 99% convinced that on the OP's machine the sprocket would have to move inwards (even if only slightly) so as to "free" the taper to the centre hub, which would then allow the hub to be removed outwards followed by the sprocket. To my mind trying to pull direct on the sprocket to get both pieces off at the same time would only tighten things up rather than loosen them and could possibly result in the hub hanging up on the splines of the shaft so hard it might have to be cut off. What none of the documentation mentions is your comment that the inner hub actually has a split in it. The problem is that nowhere in the Service Manuals does it show a disassembly procedure for the type of sprocket in the OP's photos.
Well I have managed to dig out the adaptor group No that fits in the sprocket, its 8T5243 this is for the fancy hooks that you poke in the big holes, then you just hook up to the service cylinder and suck em off, and no they dont stay put or jamb up as they come off without to much tonnage(30-40) any gap between the 2 items is full of crap and rust they come to bits fairly easy, the early 215's had very long bolts holding the front iders onto the wishbone, I used I think D6 long transmission bolts to sort them when they break, the 219 was a lot better swinger with the 225 undercart and the 215 top.
Here's a photo of the sprocket hub. Apparently it came off easily once the sprocklet was moved inwards slightly using the 4 forcing bolts to break the taper. Tony, you can see why I didn't think it would come simply by pulling it, because of the 4 slots in the hub what I think would have happened is that the the hub would have tightened on the splines and applying enough force to get it off would probably have resulted in spline damage.
Nige I cannot get the brain cells to understand those slotted bits?? the tooling I had to use to suck off the rims I was faced with was that 8T5243 stuff, this was on I am sure a CAT 215 it makes no odds but I think I still have a parts book some place for it, I know the excavator was a used import from Germany, as the Company bought 4 excavators from the same location and a mixed bag at that 215-219-225, anyhow good to see its in bits.
Tony, Check out the diagram on my post on Page 1. The tapered hub with the 4 slots in it is the one that fits on the splines of the shaft then you pull the sprocket hard on to the taper from the inside using the 8 x 3/4" bolts. That locks the hub on to the splines and fixes everything in position (allegedly). Busted-arse way of doing it if you ask me.
Ahhhh...same idea as a Browning Split Taper Bushing with a Sprocket or Sheave. Good that 1 came apart so easily, i have had to cut out the inner split taper bushing cause they were so tight.
Update: The 2nd one was easier and faster than the first.Thanks to advice on this forum. Found this duo cone info from Cat http://www.cat.com/cda/components/securedFile/displaySecuredFileServletJSP?fileId=91334&languageId=7
Good info on the Duo-Cones there for any shade tree mechanic Gregg, also for the pros as well .............
Thanks greggn! I have always wondered how something could seal in such hostile enviroments.
https://www.youtube.com/watch?v=3z1QQSQLeAM&feature=em-subs_digest