Hey, So I got a 583K (D8K), and its leaking oil/ oily substances from the studs holding the draw bar on. I pulled off the drawbar and removed the studs. Well there is definitely fluids leaking from the holes. One that didn’t even have a stud in it was full of thick oily almost grease. Then while i was standing there looking at it, water started coming out of the stud hole. I can see it dripping out of the side of the threads and running out. Now my question is, where is this coming from? The stud holes are above the level of oil in the final drives. Is there like a hidden void behind these studs or something? The oil smelled like gear oil that was in the stud holes. Basically I want empty the reservoir where ever this water is coming from then seal it up with white thread dope or loctite or something that will stop the leaks. And pretty certain the water wasn’t just trapped behind the studs because the holes aren’t rusty they were actually nice with copper coat. There was a fair amount of fluid came out of the one, probably 3 or 4 oz. The oil for the bevel gear is same as transmission correct? Currently the transmission is completely drained. Anyway, any help is appreciated
I think there was a similar issue on here not that long ago. One of the Cat experts should be along shortly.
Yeah that was probably me too. Theres this machine’s sister up on a site with oil leaking from the same spot. I wasn’t able to pull it apart at the time, but most likely its the exact same thing.
I thought the general consensus was to just stop the leaks and monitor oil levels but I could be mistaken.
Yeah at the time it was basically pretty much have to live with it for now. Couldn’t really deal with it onsite, so I would figure it out once it was hauled home. But now I found this one doing the same issue. Im mostly curious why water would be leaking from the stud holes. It cant be be the final drives as their level is below the studs. The transmission oil I just drained today, before I knew about the studs leaking. But there was no signs of water in the oil. So if the transmission didn’t have water in the oil and the final drive oil level isn’t as high as the studs. Where could the water be coming from. When I left tonight, it was still steadily dripping water from some mystery cavern feeding the cracks in stud holes.
Could there be enough room to hold the water from around the main shafts and a small crack allowing it to access the stud holes
as near as I can tell it’s somehow trapped between the two layers of the back of the machine. There is a thick plate covering the entire back that is fully welded all the way around and somehow water must be trapped in there. All day today I kept blowing the hole out occasionally and later it would be dripping out of there again. But I drained the final drives pulled the filters, drained steering clutch compartments and Bevel gear/transmission and no signs of water. Once it seems to quit im gonna goop the threads with the right stuff ram the studs back in and thats as good as she can be. I just hope the water is outta there so it doesn’t freeze and wreck something this winter.
The rear case is welded together and composed of various pieces. Cracks develop in welds in the bevel gear compartment which allow oil to pass into a hollow space behind the bevel gear compartment which sits directly behind the studs you removed. The cracks don't affect the bevel gear or cross shaft. If you weld the cracks, they'll just crack again. A situation you live with because there's no repair and no harm other than the seep between the ripper mounts (or drawbar) and the back of the rear case. I've never had water drain from the stud holes so I don't know if your problem is condensation or weather. The water didn't come from the bevel gear compartment or the finals which is why you're seeing no trace of water there. As for freeze damage, I don't have the problem, but I'd bet the water was there last winter and many more before. If you don't have freeze damage now, you probably won't get any. Draining the water can only be a good thing. The less in there, the less chance of any meaningful ice forming.
Check break has this issue in a nutshell. It is what it is. You’re going to end up chasing your tail if you’re not careful
Heres another one for ya. Same machine, got over .100” crankshaft float. Did the 8k’s have issues with the thrust bearings? Is it a simple job as replacing the thrusts? Or does this indicate other issues? I had another 8K years ago that wiped out the torque twice in a row, it ended up that it also had extreme amount of endplay, so that one went away, but I couldn’t remember if the bad engine caused the torque to fail or if the torque had been what caused the thrusts to fail in the engine. Anyway, Im pulling the engine out because it seems damn near impossible to get the pan off with the engine in, plus it has other oil leaks I could address. They don’t really give good lifting points from what I can see, I was kind of thinking just undersling the whole engine in two or three spots with some wide slings.
You’ll need TC tractors to advise you on the end play issues. On the matter of sump removal on D342 D8 engines,they can be done in situ but are not funny. Pulling the engine sounds like a good call with the other issues you mention. They are good old engines and there’s nothing that can’t be cured on them for reasonable expense
Yeah, I figure at this point of the job its not much more work to pull the engine. Backs all apart to get the pto shaft out of it, so I could get the front cover off. So its really some lines on the torq the drive shaft and a few other misc items.
We used to call that a walking crank. It takes out the T/C as you mentioned. Best you remove the engine and go completely through it. The hardest part is the sheer weight of the D342. Your most expensive component will be the crank if its beyond help. It's been a long time since I've been involved in a rebuild so I don't want to mispeak. There's areas of that engine you don't want to skip over. Tony and Bob will be your best sources for advice. Do it right and give her proper maintenance and she'll give you another 7500 good hours.
Well, looking like the crank is Kapoot. Pulled the engine today, and dropped the thrusts, and they are toast, cranks chewed out bad and needs to come out. Turns out, as I found out today this is the third time thrusts have been replaced. They had two times previously put new thrusts in it as a band aid to keep it going. So its time to pay the piper I guess. My concern now is what is causing the crank shaft to thrust so hard one way ? There must be another issue, bent crank? Twisted or tweaked? Its odd to me the damage on the thrust is thinner right in the middle than it is on the edges by 25 thou. You would think the wear would be even. Thrust on the planetary is ok between engine and torque divider so not sure if the torq is the issue? Is there a good way to check it to see? Perhaps a conrod is bent or something along those lines causing the crank to push one way maybe? The wear pattern on the main bearing almost looks diagonal rather than straight on like you would expect it to show almost as if the main journal isn’t inline with the bearing bore. Or the line bore is out to lunch. Any thoughts? Or areas to be extra careful with or “must do’s” at this point? Owners don’t seem real interested in a full overhaul But pretty certain Ive never just replaced a crank shaft without having the entire engine tore down.
Looks like you have the removal handled. No danger of turning over there. That crank looks like she won't make a core, which pushes your costs higher. What's the dampener look like. I don't think the converter had anything to do with your problem. That crank should have come out when the first band-aid was applied. Installing a new crank now without doing a full rebuild would be a colossal waste. Maybe you can find a used engine to transplant since that girl doesn't get any hard use. RR the converter (and clean the trans lube system) and send her back out on the line.
I 100% agree with you. It should get a full rebuild. It seems absurd to even consider trying to replace the crank with the engine fully assembled. I cant even figure out how I would go about it, trying to flip it upside down with the engine fully assembled?? Or trying to have all the con rods in there while trying to lift it out. Its all very ridiculous really. As far as the dampener, it was just replaced because it came off back in November and messed up the snout of the crank. This was before my time with this company, and they basically machined a thicker/special washer, so the crank bolt would be able to push the dampener on further, then put a whole bunch of green loctite in the taper bore and tightened the crap out of everything to hold the dampener/pulley on the crank. So the crank was doomed from then on. If it was me I would absolutely giver a full rebuild, new/exchange torq and make her good for a long time. Hopefully I can convince the bosses of that too. Theres too many unknowns to not check everything at this point Blocks line bore? Connecting rods straight? Crank ? Well its toast anyway Guess we’ll see how this plays out.
This should make them realize what results from a "band aid" fix. Makes no sense to not do the whole engine.
Seems as though the sheet show will go on! They insisted the crank come out and leave the rest of the engine together. So unbolted everything blocked up the crank and lifted the engine off it. Which was a complete gong show. I knew going into it, it was a bad idea, and now know 110%, it is in fact a terrible way to take out a crank shaft. But long story short, its out. I suspect maybe the torque divider could have caused this or more likely is the victim of this walking crank. On closer inspection, the thrust bearing on the planetary is worn to the point the pins (rivets) holding it there are damaged from being scrubbed. So guess it most likely should get a replacement torq. Needs a new crank shaft. All new mains and rod bearings. I noticed the backs of the rod shells are shiny, indicating there not clamped down tight enough and are moving around to some degree. Is this “normal” on this old girl? I would love to check the preload but with the rods and pistons not out of the machine, pretty hard to do. I am suspect of the line bore of main bearings as the wear on the bearings doesn’t seem straight. Also the thrust bearing is worn thinner in the middle than the ends. Seems odd ? So at this point the engine sits with the crank out, and pretty much everything else fully assembled. Pistons are pushed all the way up and liners actually look pretty decent from what I can see. Cam looks fine. Any thing else a guy should be doing at this point? Besides the obvious. I would overhaul it too if it was up to me.
For starters, Oil Pump, Crank/Rods/Rings, Bearings, and all the soft parts. I'd be leery of the dampener also. No use trying to repeat what happened. From the few that I worked on, the converter is the victim, not the cause of the crank failure, but Tony and Bob will have better advice.
Thanks. Any help is appreciated. Its a ridiculous amount of work to get to this point, only to half azz the repair and not really fix it.
I would sorta lay it over to one side, not try to lift it off the crank. So those photos show the crankshaft cracked?
The photo shows the thrust bearing flange is cracked and badly worn. The thrust surface of the crank is also badly chewed probably 3/16” deep. Plus the snout is previously been damaged because the dampner/ pulley hub came loose and was moving around
Yeah so about that laying over on one side business. It Sort of took care of that on its own. While trying to lift the block up and leave the crank sitting on the blocks, once it came free of the crank shaft, because it was so top/ side heavy the entire works rolled over slid the slings in the hook and went sideways. It happened kinda slow motion, and luckily didn’t wreck anything. So we essentially blocked it back up and left it like that for now. In hindsight being on its side would have been much better. Granted not as ideal as having a stripped engine and complete upside down but what can ya do.
Using wood blocks, of even a quick welded up jig and strategically bolted to the engine for the support, swinging the top over maybe 60 degrees plus, more of course makes the job easier. Will have to support all the con rods real well. Damper explains the crack.
The Damper explains the cracked thrust bearing? Do you think the damper coming loose caused the damage to the crank thrust? The crank was essentially being pushed towards the back of the engine based on the side the damage to the crank is.
The damper is for crankshaft harmonics. I didn't study that picture too well at first thought it was a cracked crankshaft and is why I said what I did. I suppose in worse case crankshaft harmonics could affect the thrust bearing. I would like to know the condition of the gears in the front. I don't remember the gear helix direction. Thinking about transfer shaft loading?
Looks like you are well tooled up in the crane department and that’s a nice looking 583,so worth spending on