I feel like the dog that finally caught the car! I was out working on a county machine near home when a passerby stopped and asked if I worked for the public. I said yes and that's when my troubles may have started. He said he had a Cat 983B track loader with a seized engine. Not familiar with track loader models, I thought it was the size based on my D6C with the 3306 engine in it when I said I would take it on. Wrong! Wow. Went by and looked at it today and realized it is bigger than a house and I assume built on a D8K undercarriage. After exchanging names, we realized we're both locals so I can't wash this one off as easily as a chance meeting. He told me it had started knocking so they changed the engine oil and it ran fine for two hours or so then as he was nosing off into a ditch, it seized without warning and now the starter won't bump it. After some research, I found it has a 3408 engine with a bare weight of 7K pounds, more than many of the farm tractors I work on. Short of a lifting apparatus, is this a BIG job or not too bad? It will need to be pulled back from the water's edge before beginning repair. Undercarriage is new with dozer pads and machine is otherwise in good condition so it's not a scrapper.
I think it has a 3406 in it. Later Bob
That's also what I see as the engine in a 983B in SIS and it also says: Remove engine (33) and torque converter as a unit from the machine. The weight is 4500 lb., not that bad!
I would start determining what exactly is wrong. First, get it out of the ditch and on dry level ground. Drop the front belly pan and then the oil pan. What happened, did they spin a connecting rod bearing and the mains are ok? If it is a main, loosen the cap and see if you can roll new bearing shells in, if not can you turn it over with the main cap off, if you can, you may be able to save the crank. If so, disconnect the bad hole, cut the connecting rod to clear the crank. If it turns over and nothing else looks dire, put the pan back on add fresh oil and get it started. Slowly get it on a trailer and to the shop or further surgery.
My mistake. I meant 3406, not 3408. I had found some info that said it was 6,800 lbs bare but that did seem a little high as my old 8H engine is 7K and much larger. If it is only 4,500, a friend has a trackhoe that would lift it. As I've done enough inframe work on less offensive machines, I don't think I want to crawl under it to do much, especially with the torque values needed on rods and mains (good way to tear a rotator cusp). If it won't pry over, and if he wants to go through with the repairs, I'll just pull it in field and bring it back to the shop. The trackhoe owner has a 9400 JD I might could borrow to pull it back up to better ground. It looked like maybe the hardnose and radiator have to come off for the engine to come out.
The 3406 engine is not to bad to work on I sit them on the flywheel end sometimes when I strip them out, the parts are common to find still unlike the rest of the 983, if the shovel was in the U.K. I would try to beg the job off you or at least put you off the task so I could Cop it. tctractors
My question would be why do some people think an engine that is knocking just needs an oil change? Then they put it to work for another two hours? Just think how much money they could have saved if at the first sign of the knock they shut it down, call the flat bed and slowly walked it on the trailer and hauled it to the shop! But then guy like tctractors would not be buying new Land Rover huh? People that smart I would make sign a contract before I even touched the machine. When you find the engine spun a main and damaged the block they will faint at the cost. Not saying it can't be fixed, probably can get oversized OD mains for it, or as we did a couple times on other engines is have a good machinist bore the block out and make a sleeve to bring the bore back to standard with a couple brass pins to hold it in place. Bolt on a new or good used cap then line bore.
kshansen; I have to agree. A deep knock is not something to just keep running and see if it goes away. It only gets worse and usually in a really bad way. Doing some searching, I found a used running truck engine for $4500 so if it did go really bad, maybe I can go that route. The larger the machine, the more expensive it's going to be. If the job goes through, I'll post pics of the operation.
Not sure what you will need to change to put a truck engine in a 983. Could need to change just about everything short of the heads, and not real sure of that! Don't have any experience with 3406 but I do know 3408's came in Prechamber and Direct Injection versions which I assume would mean the injection pumps and pistons would not be interchangeable. Not trying to shoot you down just giving a heads up on what you could be getting into. I know some people who have the mindset that if it's painted Cat yellow they are all the same. Ran into this problem in the past with Mack Trucks, we had everything from Gas engined B422's to V-8 Superliners and some bosses thought that as long as there was a dog on the hood they were all the same!
The 983 B has a Cat D343 engine in it. Nothing like a 3406. The 343 is a double overhead cam engine
The D342 was installed in the H model D8s correct? I thought the D343 is a strictly marine engine.
983 has a D343. 983B had a 3406.
Fact is I have only worked on a 983 not the later B series with the early Mod being powered via the D343 overhead cam motor, this engine is fitted into heaps of CAT iron 830-M 769,s motor scrapers etc and is a great engine to work on although a bit harder to tackle than the 3406,I would still try to steal the job if it was in the U.K. anyhow I would not muck about looking at big ends and stuff until the engine is whipped out and coming to bits, I would just check its locked up inside by hand then get it free of the frame. tctractors
Your fixing to learn a good n expensive lesson
I agree with TC, Could be a swallowed piston, nothing to do with the crank.
Agree on the chance anything can be done with it in place is slim to none. Pull it and stand on end have at it! Be sure to post pictures of the damage. D343, Worked on many of them, most in 988A loaders and a few in original 769 Trucks and also the 4 cylinder version in I believe a 613 scraper. The four banger could make you think there was something wrong when tuning over by hand to set valves or time the pump. Each lobe on the cams were 90º apart so as tip of lobe moved past full open it would snap over center and take up the back lash in the timing gears. Same thing with the V-8 overhead cam engines and they had twice as many timing gears plus those balance weight gears!
kshansen, the 983 any series in the U.K. is not a working track shovel that is going to calve down possibly in my life time, there is still a few about with 1 less than 20 miles from my hovel (S.E.Davis Collection) these shovels are all in private collections now that only get the few days of running usualy at a Show and are well looked after in relation to the work put to them, so this is the reason that I would do my best to steal this engine job as its not going to happen for me here, I have been told about the 4 pot motor but never seen 1 or had the ear ache from 1 but by all accounts I am lucky. tctractors
So, we started the process of figuring out what went wrong... for what it is worth, there was never heavy knocking... clicking sound when in septic hole 8 feet deep, brought it out, shut her down. Checked the oil, and the oil was a bit low, so we took the opportunity to change the oil and filters to give her a new fresh start. With new oil change, ticking sound went away and never came back for 20 hours of work finishing that job. 6 months later at the Next job, 2 hours into it - backfilling a culvert hole and backing up with bucket dumping... complete shutdown and lock up. Tried to turn over, to no avail - when I say the engine shut down - it stopped rotating / seized / etc. The CAT was not under load, and was only idling while backing up - nothing major, well except the machine is inoperable. Triage: Took the valve covers off the top, no obvious damage. Adjusted each rocker arm over the push rod and got movement out of everyone but 5 and 6. Removed the injector lines, and took out the rear rocker arm, all rods moved as expected. Valves up and seated good. Nothing out of the ordinary. Went to the bottom... Removed the belly plates - those are heavy. Drained the oil. Removed the oil pan back and front. Removed the oil pump assembly, then removed the shield plate. Inspected each cylinder from underneath - nothing. Connecting rods, bearings and the mains are ok. nothing else looks dire or out of place... So now, we are to the front - geared timing gear and water pump etc or to the rear - the transmission, possible to unhook the PTO drive shaft and disconnect the engine from the transmission / rear-end. Also, have heard rumors that the hydrostatic pump on the rear of the engine passenger side (US) seizes causing this issue - kind of wives tale, anyone heard of that before? What's next Front, dismantle fan radiator and get to front of engine to see what's what there - trying to find piece of metal locked in gear??? Rear - got to pull the engine to do that, less I disconnect the PTO drive shaft to remove that from the equation... Or, the Hydrostatic Pump - I can remove it without affecting the timing. Afraid of touching the diesel pump, doesn't seem to be the issue but understand it to be uniquely in time with the engine... Thoughts? Drop the front belly pan and then the oil pan. What happened, did they spin a connecting rod bearing and the mains are ok? If it is a main, loosen the cap and see if you can roll new bearing shells in, if not can you turn it over with the main cap off, if you can, you may be able to save the crank. If so, disconnect the bad hole, cut the connecting rod to clear the crank. If it turns over and nothing else looks dire, put the pan back on add fresh oil and get it started.
What's all this talk of a hydrostatic pump? A 983B isn't hydrostatic. Do you mean hydraulic pump for the loader?
Will the crank rotate even a couple degrees back and forth? Have you pulled the starter? Try turning crank with barring tool, assume this 3406 has the hole near the starter hole like most. How about pulling injectors to make sure it was not hydro-statically locked up from liquid in a cylinder? Have you pulled filters and cut them open looking for metal? I'd start with the engine and then each and every other filter and suction strainers. If you find one with junk in it you have a direction to go from. Seems likely that before whatever seized there would be some damage that would be spotted in a filter. Not being familiar with a 983B I'm assuming there is a converter on the rear of engine? with a drive shaft to transmission.
After removing all the filters/screens for engine, power train, & hydraulics and cutting them open to look for debris (filters) and inspecting the screens for trash build-up the first thing I'd do would be to remove the short drive shaft #10 located between the transmission #2 and the torque converter #3 and then as KSH said remove the starter and see if you can bar the engine over. Also try turning over the input shaft into the transmission. It shouldn't be hard if you put a couple of the u-joint bolts back and get a bar in between them.
Yes, hydraulic pump - passenger side lower right side of the engine near the rear. All hydraulic hoses terminate or originate from here.
@kshansen The crank will NOT rotate even a couple degrees back and forth. I have not pulled the starter - but I did try turning crank with barring tool, no joy. I tried clockwise and counterclockwise, nothing.\ Yes, I loosened and pulled each fuel line to make sure it was not hydro-statically locked up from liquid in any of the cylinders. Good Idea, I have NOT yet pulled filters and cut them open looking for metal. As far as the engine, I've got it wide open and had a professional diesel mechanic examine the top and the bottom - nothing hot, nothing discolored, nothing out of the ordinary, valves look good and rods are all intact. So, the engine is ruled out - but I need to get to the transmission and check filters and suction strainers there. Yes, with a 983B there is a converter on the rear of engine with a very short drive shaft to transmission as seen in Nige's picture. @Nige thanks for the picture - it's true that pictures are worth 1000 words. Got the short drive #10 sighted under the floorboard of the cab. The input shaft into the transmission - is that the one that is freed up once #10 is removed - like the yolk? I'll take your advice and remove the filters/screens for engine, power train, & hydraulics and cutting them open to look for debris (filters) and inspecting the screens for trash. So, any experience with the hydraulic pump seizing up and causing engine to shut down? I'm a bit intimidated with a transmission overhaul if it comes to that, but I assume it's doable in-Frame? Could #3 the torque converter lock up - I guess anything is possible, has anyone ever seen that?
Correct. Get the drive shaft out and the input drive yoke of the transmission is exposed. If you stick a couple of the u-joint bolts back into the yoke and get a suitable bar you should be able to see if the transmission turns or not. Certainly I would be cutting all the filters and inspecting before moving on to disassemble anything else. The pump on the right side of the engine is the hydraulic implement pump as others have pointed out. I'd be really interested in the result of cutting the hydraulic system filter and if anything suspicious came out of it then the next thing would be to remove that pump and then see if the engine turns at all. The only problem is that allegedly it requires the loader arms & bucket raised in order to get sufficient access to remove the pump. Torque converters can lock up but it's not common. If the TC failed catastrophically then the power train oil filter would have to be so full of debris that you'd literally have to dig it out with a shovel, let alone cut the filter looking for particles.
Check all rods for side to side movement, Then look for a spun main if the crank has no end play. Later Bob
The drive shaft should turn with just a small bar as it is, the engine valves cannot be fully checked unless you rotate the crank or remove the cams? tctractors
Removed the rear rocker arm completely, everything in the engine checks out.. valves look good and visual inspection looks good. Indications are not in the engine, but in auxiliary pump or connection such as transmission, water pump, hydraulic pump, etc.
If so you should be able to move the crank a small amount due to backlash in gear train. Have another good look at the crank main and rod bearings Later Bob
I would tend to believe that the thrusts have doubled up with no movement and no obvious burnt bearing or galled liner.
There's a wonderful film on youtube of a start to finish 343 rebuild. A friend told me about it after he had to do an emergency rebuild on his fishing boat in a small port town with no real Cat mechanical around.
First off even if the pump or converter were locked I would think you would have at least a slight movement in the crank. Like someone else said the rods at the big end should slide front and back a few thousands easy. Then you should be able to get the crank to move front and back maybe 10 thousands with a small bar. Slight possibility that a failed converter would prevent the crank from having end play. As far as loosening and removing fuel lines to check for hydro-static lock, not going to prove anything till you remove the injectors you can't push liquid back through the injectors. But I would concentrate on the other things like checking filters. As liquid in a cylinder would most likely not stop you from turning the engine in the opposite direction from normal, at least a few degrees. Filters, crank and rod end play are the main things I would be looking at right off. Then put a wrench on one of the bolts for that drive shaft Nige pointed out and see if it will turn, should be able to turn with one hand on a wrench.
I believe we have determined this is actually a 3406. The D343 is an overhead valve engine and the OP said something about removing rocker arms, none of those in a D343, but if you want to post the link to the page I'd be interested to see it for old times sake!
You mean overhead camshaft, yes..?
@Heavey Metal - what do you mean "thrusts have doubled up with no movement" what do I look for to determine that?
Huge woody here....
I'am no mechanic, but a neighbour had a D6C present the same symptoms years ago. Turns out the (output?) shaft of the converter sheared, the broken ends turned against each other, jacking the shaft apart and putting enough lateral force on everything to stall the motor and lock it up completely.:beatsme
Yes! need to read what I write! Wrestled enough of those cam assemblies in and out of those engines over the years so I should know they are in there, still have the extra long #2 Philips screw driver I used to adjust those cam followers. At least Cat did not think to use shim adjusted valves like some motorcycle engines!
I hope if you are working on that machine with the bucket up like that there is something very substantial I don't see in the picture holding it up! Have you tried turning that drive shaft between the torque converter and transmission?
i had it worse..... We had a fleet of original 777 trucks equipped with D348 engines. Double the fun.....!
@khansen - this is a pic while it was operational about 2 hours before it shut down... I have a video of it running, but not sure how to upload a video here - you can't hear the engine purring over the tracks coming down the road though... the point is that the engine was running smooth as silk prior to locking down. Now, I've got the bucket blocked up with boisdearc stumps, but it is not high enough to gain access under the arms. I had to take the hood off (300 lbs of steel) to expose the top side of the engine for access. I have not rotated shaft yet between torque converter and transmission... that's on the "to do" list when I get back on site @Queenslander - thanks, that's what I'm going for is the one off ideas that others have seen happen
The main thrusts are 1/2 s and loose held in by the main cap. When they get enough wear slack in the crank or thrust a sudden jar ( like backing out of a hole or the torque ballooning) can cause them to double up Or fold they will also get a ramp wore in them and jump up on the main cap. Your symptoms ( especially no movement) indicate this or a galled main ( I would expect to see at least .05 end play) Pulling the main cap will tell Also the torque could have the end play in a bind as was mentioned ^^^^.
I'd be very surprised if the crank is seized. Likely there is a piston melted in a sleeve. Once you get past the belly pan, and oil pan, assess the crank, and accurately measure its journals. pending its condition, & whether you must turn/replace the crank. Get new sleeves & pistons. Likely you can make repair in the machine.
I'm still wondering what's in all the filters and screens that the professional mechanic that checked it over didn't cut open?
Well- how did it turn out?
Crank not seized ... movement north and south slightly. All Main Caps move slightly, and all Rocker Caps move slightly, cam shaft moves... nothing appears to be locked in the engine
Okay, a few years later. Finally had a "right sized" CAT big enough in the area to brute force push the 983B out of the ditch and up to level dry ground - Thanks # Jody Preas Engine inspected by a sound CAT mechanic, bottom side all intact - nothing frozen, slight movement with every main and all 6 rockers, as well as CAM shaft reveal that it's not seized in the engine proper. All filters are clean from debris. Rear #10 shaft turns freely, between Transmission and Torque Converter - so no problems in the rear trans. Lowered the access cover and drained the TorqConv - no debris and no noticeable breakage. Attempted to back engine off with reverse force - no joy, no movement in crank - absolutely none. Starter won't touch fly wheel, same as when it went down. Now going up to the Hydrolic Pump - removed fluid, going to remove that pump from the fly wheel to rule out the back side of the engine. Removed 30 Gal of HydroFluid, noticed screen intact in bottom of tank - so no debris went from "Tank" to high pressure "Pump" thru that screen... thinking something is wedged somewhere. Once that's done / we will dismantel the front to see if the timing gears are ajar.
yes - turns easily
Thanks - good idea.
If the shaft turns freely, I think you can safely disregard my theory.
After thinking back on my 3208 seizing to the point it wouldn't move at all and finding a piston locked in a sleeve (but with obvious lower bore damage), I am wondering if maybe one has galled on the topside and without any visible damage below it in the sleeve. I am awaiting a bore scope that might be poked down an injector hole if possible. Not being familiar with this engine, I don't know if I can as is possible on my 3306, 342 or 3208. I don't want to start doing a bunch of exploratory surgery without some reason for doing so.
is there any further news on this thread am really curious what if anything has been determined ?
Are you sure you did not drop a valve i have seen the valve imbed in the piston freezeing it in the cyl.
Most recent work on this project was to drop all rod caps and see if crank would free up. All pistons are free in bores. I had to cut 2 cap nuts off but crank still won't budge at all. I'm afraid the next step will be disconnecting auxiliaries then going into the timing gear train. Being as big as it is and not being able to get to the engine from such an great access design (sarc!!) this will be a royal pain in the ***.
Well if the pistons are free and the crank is free I would wonder if something in the flywheel housing has come loose and wedged between the flywheel and housing I would pull the hyd pump first and see if you have a problem there either way I bet the enging has to come out
Just did a quick read through of this thread. Did not see any mention of the starter being removed, it was suggested at on point but did not see it being removed. Reason I mention this is one time a few years before I retired the 988H at the quarry failed to start after being shut down for lunch break. Starter was making bad noises and when removed reason was obvious as the "nose" of the starter was missing. That is a pretty big chuck of cast iron to have loose inside a flywheel housing and I could see it getting jammed in there and locking up the engine. In my case we were lucky and after about three hours of poking and shoving various things in from either side of the flywheel housing we retrieved the nose and there were only a few little pieces missing less that a grain of rice!
from what im reading here sounds like my next step would be to loosen all the main caps see if the crank would move then . this sounds like a seized main bearing , but could also be a crashed gear train in front , even with that the crank should move back and forth somewhat maybe only 8/12 thous. but should move 1`m asuming this is a 3406
I think he said it does move about that much.
He said he had end play
well guess i missed that part
Any update on this?
Forgot about this one, would love to know what the outcome was.
Myself as well.
me tooo !
I was supposed to meet with him and a local Cat guru before our latest monsoon set in and haven't been contacted since. With it drying out and on my mind, I'll make contact and see where the project is. I'm the only local equipped to handle it and the guru is contracted to a local landfill operation so I'm likely still on the hook for it. With the loader down, I had in mind putting a port into a steel boom lift line and raise it with a farm tractor remote and then lock it up.
if you're gonna port into the hyd system and use your tractor to raise the boom,better bring about 10gallons extra hydro fluid with you,you'll be needin it..983 has BIG lift cyls
For all those who were watching this thread, I finally found the reason for the seizen. The last stab at identifying the problem, I was in my old service truck and lacked a couple of special tools I have now that allowed me to get to the remaining #4 rod cap off which is directly above the crossmember and nearly inaccessible along with high bolt torques. All my previous experience with rod bearing failure has been a burnt looking rod cap that was obvious on pan drop. Not this one. It was clean grey just as the others. Problem solved. Now for the fun part of removing the engine for rebuild with the loader frame partially down. I had always dreaded getting an engine call on a TL with the loader down and what do I get, pulling the engine in the largest model ever made! Thanks for all the members here who have given me great advice since I joined back in 2011. Signing off due to several jacka$$es on here now that forget this forum is meant for help and a little fun to boot and not berating and ridiculing those of us legitimately wanting sound and experienced advice. I can easily find those types without coming here.
I to have been wondering whether you found the cause .glad to hear it was found and will be remedied . don`t let a couple jackasses keep you off the best forum going
Please tell us that you are not leaving HEF permenatly ! Ignore the jackasses, there are halfwits on all forums. Report them to a mod and maybe they will ban them.
Komatsu made an even larger track loader. I'd be worried about having single grouser dozer pads on a such a heavy loader. Puts way more stress on final drives when turning. Also tracks look too tight.
Stick around. From a purely personal interest I want to see how the 983B job plays out. Especially interested to see the crank and #4 rod bearings when you get the engine out.
tracks will often look tighter if run in reverse and stopped without going ahead
stick with us wrwtexan,Ive been waiting for an update on this job. should be a simple fix,just on a lot bigger scale than most can handle.
I have been told that these 983's are around the size of the old D8 H bulldozers...is that correct ? Are they the same running gear underneath as a bulldozer ?
I do not think the UC is the same thru and thru, rollers alone would need to be heavier for the loaded side loading. Sprocket segments, idlers and base frames MIGHT be.