Hello All, Like stated in descripiton, the dozer will not move under power. I need explanation/clarification on the steering clutch system. Tractor is a 1982 Model 28Y00977. It has been sitting idle for at least two years. Previous owner passed and it was tied up in probate. The transmission dipstick reads overfull when engine is off. I haven't been able to run the engine long, because the bottom of the radiator is rusted out and it won't hold coolant. In any case I know it has hydraulic actuation for the steering clutches,because of the hydraulic lines on top of the steering clutch housings, but I thought the clutches were always engage with spring pressure, so the tractor should move if the transmission output shaft is turning. Am I wrong about that and I need hydraulic pressure to engage the clutches? I'm pretty sure from reading on this forum that I have dry steering clutches. The floor pan is removed, so I can look down and see the driveshaft turning, but I haven't gone as far as putting gauges on the test ports. Thanks for any and all input. Leroy
When the clutches engage the driveshaft you see spinning will stop spinning. It then turns slowly as the machine moves. Tansmission suction screen and all suction hoses should be checked for leaking air inwards. Could try putting a small hose on the discharge side of charge pump while putting 1-2 PSI of air on the transmission sump with a hand blow gun with a rag ball to seal the gun pipe going into the transmission sump with the engine just started. It is common for the charge pumps to become air locked after sitting a long time. Air helps to push the oil up to the pump, while the small hose hooked up, or output side of pump loosened off helps to get the pump moving oil again. I don't have a manual on your machine, but this is just a principle I have used for a long time. Simon C
I think you should get radiator fixed so you can run it longer it might pick up on it's own Pressure taps for transmission are under the round cover on top plate of the transmission they are 1/8 pipe p1 is the one you want should be around 350
Simon, I don't understand. You say when the clutches engage the shaft will stop spinning. Isn't the drive shaft connected directly to the pinion? Do you mean when the steering clutches engage? I thought the steering clutches were engaged all the time and only disconnected from the final drive when you push the steering/brake pedals for that track. If the transmisson out put shaft is spinning, doesn't that rule out the transmission for the moment? If the drive shaft was stopped, I'd know the transmission is not putting out power. I don't get how the shaft is spinning but the tractor isn't moving. Am I missing something here? Leroy
Question does this machine have a winch?? If it does you are looking at shaft for winch shaft for bevel gear is below it
Indeed it does have a carco 28 winch on it. I didn't notice it had another shaft under it.
it's pretty far down in there
You may find the attached of some use.
How much RPM were you giving it? After sitting it may take full throttle to get it moving. The tracks could be a little bound up too. I agree with fixing the rad. first. Then I'd put blocks under the winch and lift the tracks off the ground with the blade to see if the tracks will turn with the least amount of load on them. My loader version takes a lot of throttle to get moving after sitting especially when it's colder. I have a backhoe so it's easy to lift the tracks up to get them moving. Try the simplest stuff first.
Sorry man I was thinking of power shift, shaft always spinning and engage it in a particular clutch and only turns according to the gearing. When holding brake pedal down to torque stall in high gear shaft stops spinning when engaged. Forgot what type of power train you got. Simon C
On the Komatsu stuff that I worked on most the Torque is hooked up through drive shaft directly to the transmission input shaft. Little different set up and no drive line from transmission to bevel gear. Just a pinion gear coming out of transmission that turns the crown gear. So when the drive shaft turns fast in neutral it stops when a gear is selected Last torque I did on a Cat was a D7G and about 18 years ago. You will get it figured out. Simon C
Looked at the systems operation that Nige sent you and if you have the winch driveline turning which isn't in your first post, you can still have problem in torque and transmission. But if the drive line going into the bevel gear housing is turning and nothing is moving, you will be into an exploratory surgery in the back end. Without manuals on these things we are sometimes just taking a wild stab at problems and simple solutions like bleeding pumps and checking filters and suction lines. Newest Komatsus are just drive shaft off of engine running large hydrostatic systems. Simon C
Let’s not get excited winch is a direct drive to torque it turns as soon as torque is full of oil and working on the other hand you have no input to steering clutch’s until there are two clutchs engaged in transmission. As I’m typing this I just had a thought since these transmissions are known to have a problem with the rotating rings in low gear have you tried 2nd or third??
PCM, I did try all the gears. I do have the complete service manual for the tractor and I've been reading it. I was going to ask about the winch pto shaft. I gather from your last post, the winch pto shaft runs off the torque converter, so at least that's working. I didn't get back out there until late this afternoon and I fabri-cobbled together a bypass for the radiator out of pvc pipe and filled it with coolant. I only heard it run dry and I want to make sure I didn't get water in the oil before I paid for it. All was going well until I believe it ran out of fuel. I now see the output shaft below the pto shaft, so thanks for pointing that out. I'm headed back out in the morning to put fuel in it and get it running again. I haven't looked at the manual yet for radiator removal, but if the front cowl has to come off, that will be a no go until I get it to my place where I have equipment to take off the limb risers and the heavy front cowl and radiator. Thanks to all who replied and I'll keep you posted on the progress. When I get it started up with my radiator bypass in place, I can run it longer and monitor temps with a temp gun if the water temp gauge is not working. Then I will try all the suggestions to get it moving so I can load it on a trailer for transport. I have a set of test gauges ordered and will do the transmission pressure test and post results, probably be Friday night or Saturday if I don't get it figured out before then. Once again I appreciate all the help and suggestions. Leroy
The nose has to come off to remove the rad. There's some small, I think half round, pieces used for holding the rad. in place. Make sure you don't lose them. I had to take the nose to a rad. shop complete because I pulled it off in the field in winter. The guy at the rad. shop was kind of a jerk despite charging me $1100 for a new core and dipping it in solder for added strength. They took the rad. out but I had to put it back in. Pretty simple to do once you see how it mounts. That's when I discovered the pieces were missing. They fell behind a work bench but thankfully they found them. Not too pleased since the nose and rad. were an hour away. I have no use for companies with zilch for customer service skills. Have you tried lifting the tracks off the ground and seeing if they move with increased throttle up to full throttle? I think there's a good possibilty you can get them moving with the least amount of resistance on them. When my 931B sits for awhile I let it warm up for a few minutes and it's not uncommon to need to use 3/4 or more throttle to get it moving. The tracks themselves could also be a little or a lot stiff from sitting. It seems to me the simplest test if the transmission oil is full and you don't hear any strange noises.
Well, I learned a lot more today. 1. Never let it run out of fuel if the primer pump is siezed and you can't pump the air out to the injectors to bleed it out 2. The first 3 hours of a five minute job are the most difficult. 3. I let it run for about 10 minutes after I got it started and then ran it full throttle and shifted gears. No movement at all from the output shaft to the bevel gear. 4. Raised the blade up and discovered a leak on the hardline below the blade control lever. I think it rusted through, so I have to replace that before I can use the blade hydraulics. At least I know the hydraulic pump is good. I have the blade chained up to the ROPS for now. 5. The winch control lever is also siezed up solid, so until I get that rebuilt, the winch is out of commission. I read up on it, and it's basically a master cylinder that engages the clutch one way, brake applied in the middle position and free spool in the aft positon. Interesting that it is not connected to the tractor hydraulics at all and uses DOT3 brake fluid in the system. Now on to the questions. Is it possible to pull the dozer with a 10K mile marker hydraulic winch on my superduty? I can double or triple the line if I need to and I know from experience I'll have to chain the truck to a solid anchor point, but I need to move it from it's resting position to somewhere I can get a trailer in front of it. I haven't given up on the transmisison, but I need gauges to continue testing and they won't be in until Friday.
If the tracks are free you should be able to winch it but the tracks being a little bound up or rusted could be why it's not moving. I got my machine stuck in a bog breaking through a frozen surface and all around the sprockets was packed with wet muck. I had nothing to pull it out with so I had to wait a few days until the gravel pit was nice enough to haul a D5M over to try pull it out. The track and sprockets were frozen solid. I put a big tarp over it and used a torpedo heater to try and thaw it out. Many hours later put it in 1st gear at idle and revved it up to full throttle but it wasn't moving. I was worried I'd damaged something but asking on here was told it should be OK. I had brand new steering clutches and brakes. I didn't slam into gear at full throttle. Finally got one side moving and put the heater close to the still frozen side. That and careful heating with a weed burner got that side moving. I'm only saying all this because you don't know if the tracks are free rolling on your dozer. Lifting them off the ground puts a lot less load on the drivetrain. What you could try is hooking your winch cable to the elevated tracks and see if they turn easy if they don't turn under machine power. Once you're sure the tracks are free then you can look at doing pressure checks and other troubleshooting. If the driveshaft doesn't turn when in gear means the transmission is doing something. Everything has to be free for it to move though.
I did some more work on it today, I got a new hydraulic line for the right side blade lift and removed the hard line from the blade control valve. It has a pin hole in it and I'm going to try and tig braze it tomorrow. I also hooked my winch up to the back of the tractor and tied my truck off to a big roll off dumpster that was behind me. Doubled the winch line and proceded to pull both my truck and the dumpster toward the dozer. The dozer didn't budge as far as I could tell. I'll get the hydraulics repaired and try to get it up on blocks and contine with troubleshooting.
Here is something for you to try push both pedals down at the same time a lot of time you can hear the transmission and cross shaft making noise if it's turning try it in all gears forward and reverse also try engaging one clutch at a time. be careful in case it decides to turn. also I'm thinking that machine with the parking brake off and nothing frozen up should roll pretty easy
It spun to get started rolling but I pulled my 931B away from the backhoe attachment with a 4800lb. skid steer. Guessing you need about 3500-4000lbs. pull if everything is free I REALLY THINK YOU NEED TO GET THE TRACKS OFF THE GROUND AND GET THEM TURNING! If the winch control is seized up why couldn't other things like the tracks be a little seized up??
More work on it today, I reinstalled my brazed hard line and picked the front of the machine off the groud with the blade. I discovered a fuel leak from the tank, but I can't see where exactly. I'll take my bore scope tomorrow and see where it's leaking. Hopefully a fuel line, but knowing my luck it has a hole in the tank. I'll check the transmission pressures tomorrow afternoon when I get my gauge set and see what's happening with it. I get the feeling that this machine has set up a lot longer than the 2 years since the owner died. I will also get the machines tracks off the ground tomorrow and see if the tracks are free to turn.
I seem to remember the fuel lines are steel hopefully you'll get lucky and just have a line leaking
Pushing 1-2 PSI of air into the fuel tank with a blow gun pipe into the tank and a Rag Ball stoping the air from coming back out violently can expose loose hoses or cracked hoses that leak. Simple test with 2 people. Simon C
If it was sitting for 2 years plus it's even more probable the tracks could be a little or a lot seized up. I'd get them free rolling first and you might not need to hook up any gauges. If the machine sunk in the ground from sitting would also make the tracks a lot harder to get rolling.
One guy told me I had changed his battery cable 2 years ago. I had to remind him it was 7.5 years since I did it. People sometimes lose track of how long something has been sitting. You may be totally correct Dave and tracks may be stuck heavily to ground. One thing about it, it doesn't cost big dollars to jack up and free tracks from ground. Simon C
Add 2 years to any recollection of passage of time to account for the wuhan wormhole
I hear you all! That's why I had to repair the blade hydraulics so I can get the front off the ground. I'm working on getting some pieces of 8x8 cribbing to put under the back. I didn't get back to it today, wife and I were running errands this morning and I was kinda waiting on UPS to deliver the gauge kit. Didn't happen before dark, so I'll hit it early in the morning. One thing on my mind is that when I put it in any gear forward or reverse, I don't hear the engine load up. Is that normal? Shouldn't the engine bog a little until the governor ramps up the fuel if the tracks or brakes were siezed?
I would say yes to being able to hear the engine change speed as it goes into a gear. Hooking up gauge as pittsburg cat man said would be there fore sure on list of stuff to check. If pump is air locked, air to transmission sump would possibly help to bleed, but needs to be controlled air. Simon C
If you put it in gear at idle might be pretty hard to tell if engine is loading. Try going full throttle then pulling it into 3rd gear if it goes into gear you'll hear it. Don't worry about a full throttle into gear they were designed to take full throttle shift. I say to go to third because brakes should hold 3 rd 2 nd or first it will prob drive thru brakes if it breaks loose
I forgot that your winch was turning so your torque is full of oil. Try what pittsburg cat man stated and see if anything breaks free. Simon C
I don't think I ever had the engine load up that it was real noticeable but I don't put it in gear at full throttle. I don't recall the engine loading up when the tracks were frozen solid and I did try higher throttle. Maybe the torque converter is slipping?? I think if you could make sure the tracks are free would be a good first step.
More adventures today. I got the gauge set and then couldn't get the tractor started. I put 10 gallons of fuel in it Tuesday afternoon and today it wouldn't start. I cracked the injector line and got air. It started fine Thursday. The only thing I can figure is vibration from running opened a rusted hole in the fuel line more and allowed it to pull air in. I opened the fuel line and put a 12v fuel pump on the tank side and pulled about 4 gallons out before it quit pumping. That means I lost 6 gallons of fuel to a leak. I then connected the pump to the engine side and bled the injectors and got it started again. Now running off of a 5 gal gas can. Now on to other news. 1. I have zero pressure on the pump test port on top of the filter housing and also zero pressure at the P1 test port. 2. I anchored my truck off to an old tour bus sitting behind the dozer and doubled the winch line. After a few butt puckering minutes, I got the dozer to roll backward out of its grave. That means the tracks aren't siezed up. I pulled it back about it's own length out of the hole it was sitting in. Now I need to get the pump off and find out why it's not putting out pressure. I did remove the filter and checked it over. No signsl of debris or clutch material. The oil is contaminated by moisture, but it still looks and feels like oil. 3. After reading the sequence of operation, if the pump was not putting out pressure, the torque converter wouldn't turn and thus the PTO shaft to the winch wouldn't be turning either. Could the trouble all be in the valve body on the transmission?
I might be wrong but I would of with the pump pressure port opened up. put air to the Transmission filler pipe with it running for 5-10 seconds and if the oil blasted out that test port, you then know it was air locked. Have done the same thing on a Cat 980H that the pump would not pick up after oil change, opened the pilot pressure port with a hose into a pail while putting air to the hydraulic tank sump and three seconds later oil coming into pail and boom going up. Air lock can happen after sitting a long time. Simon C
My D3B doesn't have a pump to move it to injection pump, it's gravity feed. Mine also doesn't have a primer pump 27Y03918 That said, I had my Inj pump rebuilt when rebuilding the motor
Thanks Simon, I looked over the sequence of operation and now I'm not too sure it's the pump.
I understand Alldodge, but the fuel pump is on the engine and the hole rusted in the fuel line is by the tank letting it suck air into the line. That why I put an electric pump on it for now and run it on a 5 gal can. When I get it to my shop, there are a lot of issues that I will repair. For now I'm just trying to get it moving enough to get on a trailer.
Been looking for my thread when I got into measuring transmission pressure points, so far unable to find. Mine has always moved but has issues moving anything with blade down other than in 1st gear. The guys hear helped me measure the spots and it's here, I'll keep looking
Post number 8 from Nige has a Testing and Adjusting section. Thought I seen where to hook up the gauges there. Simon C
what is near 0 at p1 what size of gage do you have on p1 ?
Good point. 5000psi gauge would be the wrong one. Simon C
I'm interested if p1 is around 85psi
The gauge I used is 0-150 psi. I have the Cat Shop manual and I connected to the port that is labeled P1 in the manual. Top right of the three test ports. I also connected to the port on the oil filter. These gauges have adapters with the minimess fittings.
That gage is too low you need at least a 500 psi gage. The top plate on valve should be marked one other thought gage didn't go the whole way around ? is it still on zero when it's disconnected?
Good that the tracks are free. Would still be a good idea to lift them off the ground when trying to get them to move under machine power. If you could turn them some might help to get the transmission working.
Well, it was a productive day at least. No work on the dozer, but we go it winched up on a trailer with a little help from my Cat skid steer. Got her transported to my shop without incident, so that's a bonus. Now I have all my tools and equipment to get the nose off of it and see if the radialtor is salvagable and see if the tank is leaking or it's just the fuel line. I'll keep you all posted on the findings and what I have to do to get it operational.
Now I'm getting somewhere. I checked the pressures again....Nothing, zero pressure, but the torque converter is still turning the winch output shaft. I loosened the inlet connection from the pump to the filter housing and started her up. I got some fluid out, so the pump is moving fluid. Then, because the fluid is contaminated with water, I drained it all out. The I removed the inlet screen to the pump and found it was packed off with some sort of schmoo. I took a picture of the stuff I scraped out of the pickup screen. Next, I'm going to pull the valve body of the transmisison and take it apart for a good cleaning and inspection. It has some surface rust on the top of it, so I want all that gone before I put fresh oil in it. I'm probably going to have to change the oil a couple of times, unless someone knows how to drain the torque converter.
Hard to tell what the black schmoo is it lumpy of just like paste when you tear valve apart line everything up with the bore it came out of and watch for shims one important thing there is a screened orfice in valve on bottom side of pressure control do your self a favor and change it they have a habit of breaking and plugging the orfice
I'll second that. If it has never been changed before the plastic of the screen body will probably resemble something akin to glass. #12 in the illustration below. Also O-Ring #19. There are a couple of orificed plugs, #34 & 35 that also need to be inspected closely to make sure that the orifices are not plugged. Those two plugs are metal not plastic so will go again provided that the orifices are clear.
That black schmoo is nasty looking but explains why it's not moving. Can't remember if you have a 3F/3R transmission. If so you could check if the filter is full of the same stuff. Definitely needs a good flushing and the parts listed above. They're generally a pretty reliable transmission from what I was told.
I took a trip to the Cat dealer today and got oil and transmission filters and an o-ring for the cover of the pickup screen on the bottom of the transmission. I was going to pick up the orfice tube and seal, but that has to be ordered and won't be here for a week. I'm trying to get it moving before Monday. I took the valve body apart and got all the pistons under the cover plate on the rear of the valve body out and looked at the orfice screen and it looks ok, so I'm going to leave it for now. The manual says to remove the detent assemblies from the top and bottom of the valve body, but it doesn't show or say how to remove them. I tinkered with them a little bit, but I don't want to damage anything. Does anyone know how to remove them?
look at post 48 number 6 roll pin holds it in has to be driven out
IT WAS THE SCHMOO! I pulled the valve body and took it all apart and cleaned everything in the parts washer. There was a little corrosion in the valve body, but I don't think anything was stuck. The plastic orfice was in good condition, so I ran a little parts washer fluid through it and blew it out with air. I cleaned it all up and put it back together. I dumped 5 gallons of TO4 30wt oil in it, crossed my fingers and fired it up. When I dropped it in reverse it hesitated for a second and then started moving. I tried all the gears forward and reverse and it seems to work in all of them. Yay! Now I have a dozer that moves forward and reverse under it's own power and also turns right, but not left. I still have to troubleshoot the steering clutch on the left side and find out what's going on there. It might free up after a little more running. A big thank you to all who answered my questions and tried to help me out. This machine is in really good shape under carriage wise, it has salt chains and pyramid swamp pads very little wear on the sprockets and lots of adjustment on the forward idlers. The cylinder bushings have no slack, the track frame bushings are tight, and I think I only have one leaking cylinder on the blade tilt. The engine fires up pretty easily and doesn't smoke after running a bit. That's the good. The bad is it has set out in the weather so long the seat frame, seat pan and battery box are rusted through. The radiator is rotted out on the bottom and I don't know yet if I can repair it or I'll have to order another one. The boss for the grab handle on the drivers right has rusted all the way into the hydraulic tank, there is a 3/4 inch hole in the top off the tank, and the hydraulic system is contaminated with water. You can't read any of the gauges, but I installed and oil pressure gauge I had lying around and it has good oil pressure. The fuel tank or fuel line is leaking and I have to investigate that. I'll also have to replace all the 43 year old hydraulic hoses on the machine, but I think about $2500 will get that all sorted. Big thanks again to all Leroy
Glad you finally got it going. Unless you are planning on working in a swamp you really should replace the pyramid pads with regular ones unless you want to tear up the rest of the undercarriage in short order.
Thanks, the swamp is where I want to use it, I have a big creek bottom that I want to clean out. I also have to repair the winch controls in case I get in a little too deep.
Hint for the steering clutch look at roller on steering valve and the cam that works it
In those circumstances fixing the winch might not be the worst idea in the world.
Thanks I'll check the steering valve in the morning. The winch has to work for sure before I dive into the creek bottom.
If the rollers on the steering valves have flat spots the valves have to come out so the pin holding the rollers can be pressed out. Good to check if the valves are leaking too. I had one that shaft had to be rechromed.
Had a few issues with my D3 in same area and here is my tread where I fixed the issues. HeavyEquipmentForums
Thanks for all the input and I'll keep it saved for later on. Turns out all the old girl needed was a little exercise. I ran it back and forth a few times and she started turning both ways with light pedal pressure. I pulled the trans dipstick and expected to find milky oil, but it seems to be clear. When I get the radiator fixed/replaced and the seat pan repaired, I'll give it a good workout and then change the transmission oil again. I looked up a lot of replacement parts from finditparts.com gauges, air cleaner and gaskets)and they seem to be reasonably priced. Does anyone have experience with them?