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Hi Ron,
I haven’t had that part of my hubs apart. I replaced the seals between #42 and standing shaft housing #25. Something I would call a king pin housing. Interesting that they use the same seals in both applications.
It sounds like the gear is a press fit on the shaft and the two half washers are the friction surface. I have never seen that before and if that is all that holds the wheels (shaft #33) onto the tractor it seems a little iffy to me.
Based on the surface area of the washers it must be a pretty tight press fit. It would take a pretty good gear puller to get it off of the shaft if that is the case.
It looks like there is room enough between the gear and the cover to get a press plate in there for use in a hydraulic shop press but building the supports to reach around the shaft and cover will be a challenge.
From the drawing in the frontaxleservice.pdf it looks like you won’t have to move the gear very far to clear the half washers. I never would have guessed that is what they are or their purpose just looking that the drawing. And the way the gear is tight to the shoulder on the shaft you would never guess that there were half washers inside.
If you can, please post pictures as you take it apart.
Hi Ron,
I’m not sure I follow your reference to two half washers.
Here are some diagrams with numbers. What seal are you after and what gear is in your way?
I have only had mine apart far enough to replace seal numbers 28,29 and 30 from the parts diagram. That was a real pain and I had to put speedi-sleeves on the shaft where the dirt in the old seals had worn groves in the housing. Don’t scrape the gasket off of the top cap, it is a thickness shim used to set the backlash on the gears. As long as you aren’t messing with the gears, everything should be fine just putting it back together. Unless of course your backlash needs adjusting.
Good work Len. I would say that the fuse box mounting leaves a little to be desired. It is subject to a great deal of vibration being out on that long moment arm and the grounding back through all those bolted connections is bound to introduce resistance to the circuits. Nickle based anti-seize is your friend on all those bolts. A cross brace a the end of the bar holding the horn would help a lot. The brass ends that are crimped on the wires will work harden and break. Ask me how I know….
Hi Len,
No, don’t wire it to the idiot light. That could mess up the voltage regulator.
The purpose of the amp meter is to show current flow of the whole system.
Follow the positive wire from the battery to the post on the starter. That is just a connection point and does not involve the starter motor. It then goes through the master fuse (30 A) and then to the gauge then to the hot side of the switch. With the key off, nothing is flowing anywhere. When you turn the key to run, then all other circuits (except the alternator) are fed through the switch. If you trace the wires you will see that the idiot light is connected to the regulator and is not fed through the amp meter.
David was right, if you take the hot wire off of the switch (the one from the 30A fuse) and put it on the gauge where it is marked – Then connect the the gauge side marked + back to the switch where you took the other wire off you will have the gauge inserted into the main trunk of the system. It will be in the circuit between the alternator and the battery where it can indicate flow to/from the battery.
I am surprised you tractor didn’t have a gauge in the first place. Do you have a wiring diagram for your specific tractor? Jinma usually put little plastic tags with numbers on the wires for identification.
What you described as a horn sure sounds like it is. A picture would tell for sure. Also, there is a relay involved. If you are seeing battery voltage at the switch but nothing happens there are two possibilities. 1) the switch is not connecting to ground or 2) the relay is not closing properly. Follow the path from the battery, through the fuse and down to the relay. From there you can see where completing the circuit through the switch will activate the relay and connect terminals 30 and 87 internally.
To test the horn connect a jumper wire to a hot connection point (battery, starter, or B terminal on alternator) and momentarily touch the terminal on the horn. Also, you can put a test light or VOM on the terminal and watch it while hitting the switch. No light is probably a switch or relay problem. If you are getting power to the horn but no sound it is a ground problem or a bad horn. You can replace it with any 12V horn you can find at any auto store.
Here is the schematic for my 284 so you can see how the factory did it. I added a small volt meter so now I can monitor battery voltage as well as alternator voltage. The amp meter allows me to see how much current is flowing through the system and in which direction.
The plastic screen is a little hard to see but it might have what is known as “bugs” trapped in it. There is a strain of bacteria that live on diesel fuel and once a tank gets infested it can really cause problems. When they die they sink to the bottom of the tank and collect in screens and filters eventually plugging them. That is not the worst part though, the dead ones (and maybe their waste) is highly corrosive and damaging to anything metal. The bugs live in water that gets into the system. There is a whole other discussion about bugs.
If there was no oil in the IP or governor it very well could be that the governor is stuck. Same goes for the fuel cut off rack. Did you test that to see if you can feel it moving? Take a look at page 40 of this document.
http://harnerfarm.net/Jinma/Files/jinma_manual.pdf
The stuck hand pump plunger also speaks to either rust or bugs. It should turn counter clockwise until the threads release and the spring pushes the plunger up. I suppose it could have dirt in the threads or be cross threaded but something is not right there. In any case I think you can safely remove the plunger assembly from the lift pump body casting. It appears there is a hex surface to put a wrench on where it meets the main body just above where the hose connects.
As for using a solvent in the IP/governor, I would just fill it with diesel and let it sit. I would leave the rubber cap on the overflow tube and fill it all the way to the top. After a day or so, pull the cap and let it drain until it stops dripping. Then hit the starter for a few seconds a couple of times to slosh the diesel around inside. Let sit another day or so and hit it again. Then pull the drain plug and let it drain completely. Fill with engine oil and have another go at cranking and checking for fuel flow at the injectors. Hopefully this will free up whatever is stuck.
I think you are probably OK to take the housing off of the governor end so you can have a look-see inside. Just be careful not to let any parts drop out. I wouldn’t mess with the IP side of things or the IP to engine mounting.
At this point I am still leaning on a stuck rack due to rust and/or bug corrosion. No oil didn’t help any either.
Let us know what progress you make.
The fittings on my 284 with a Y385T engine were surprisingly 1/4″ NPT. Hope yours are too.
The valve in the oil filter is likely referring to the bypass valve that lets the engine get unfiltered oil should the filter become plugged. I wouldn’t dump oil back to the sump and cause no pressure. A plugged filter could cause low pressure though.
When you turn on the key switch but before you crank the engine, look to see if there is a light on the dash that comes on. The ones I have seen had a light for the alternator and one for the oil pressure in addition to the gauges. Mine has both and One time I got the wires mixed up between the sender and the switch for the light. Boy did that show some goofy readings until I figured it out!
I would suggest getting a generic mechanical oil pressure gauge from any auto parts house and installing that. At least to confirm the function of the electronic gauge.
Do you also have a low oil pressure “idiot light”? If so is it on too?
If both indicators say low oil then it probably is low. But if they don’t agree with each other, it is probably the sending unit or the gauge in the dash.
Either way a mechanical gauge is probably cheaper then chasing parts without knowing for sure which one is bad.
OK, between I and II there should be a sediment bowl with a screen. This traps debris and water. Important thing to have.
VII is the hand pump or hand primer pump. It is mounted on the lift pump which is operated internally from the main injector pump. It probably has a plunger that runs off of a cam on the IP crankshaft.
The IP is connected to the gears under the housing on the left of this picture it is timed to the engine using the slots that mount it to the gear casing. On the right side of the IP is the governor inside the housing. More on that in a moment.
The hand pump is used by unscrewing it just like a bottle top. It is under spring tension and will pop up a little when unscrewed enough. This is used to prime fuel all the way though the IP. Both the hand pump and lift pump run fuel out III and up to the filter. From there it flows down to IV where it enters the IP.
V is the bleeder screw. You turn it open (counter clockwise) a half a turn or so and then pump the hand pump until all bubbles stop coming out of the bleeder. Then close the bleeder and push the hand pump plunger down against the spring and turn until it is tight. The engine should start puffing after a few seconds of cranking.
Side note here that is a bit of a controversy but Caterpillar recommends that fuel filters be put on empty, do not pre-fill as this increases the chance of dirt getting into the system on the IP side of the filter. Not good for the IP. Clean the old filter and housing. replace filter then use the hand pump to purge air from the system. Others will disagree and recommend pre-filling the filter.
Anyway VI is the injection lines leading to the injectors. You can crack the nut loose to make sure fuel is getting out of the IP at that point. You can also do this at the injector end of each line.
Two more things. The lever on the governor housing at the right of the IP is the throttle linkage. Stuck throttles are often caused by stuck governors. The governor is lubricated with oil that needs to be changed regularly. There is a drain plug on the bottom of the IP and there is a breather cap on the top of the governor that you remove to fill with fresh oil. Just use whatever engine oil you use. I change mine at each engine oil change. Anyway, there is a fitting to the left of the lift pump that looks like a screw with a short piece of pipe on it. There is a rubber cap that covers that pipe. When filling the governor you take the rubber cap off and fill until oil runs out of the pipe. Let it sit until it quits dripping before replacing the cap. This sets the correct oil level for the governor.
Above and behind (in this view) the throttle is the fuel cut off cable. This cable attaches to a lever that is spring loaded. When you pull the fuel cut off this lever is actuated, stopping the engine by cutting off the fuel internally in the IP. The lever turns a shaft that moves a rack inside. It is possible that the rack is stuck in the cut off position and you will not get any fuel out of the IP no matter how much you crank the engine. I would manually move that lever back and forth a few times to see how it feels. I have never had this problem and don’t know what it looks like internally but this pump is a knock off of a fairly standard Bosch pump and should be built the same way. A search for Bosch IP cut off rack should provide some answers. A stuck rack is not uncommon and will cause exactly the symptoms you are having.
Good luck and let us know what happens
Try a local electric motor repair shop. They sometimes have “universal” brushes that could maybe be modified.
Another place would be a good old fashioned auto parts store that has real clerks, not just keyboard monkees. Take the old one to show them and ask if they have anything like it. If they insist on make and model to look it up, you are in the wrong place.
good luck
