JD 300 Industrial Backhoe Loader starting problems

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1976 John Deere 300b Backhoe Loader (Industrial)
1020 CID 135 Gas Engine (Deere, 3 cylinder)

I've been working on this tractor for a few weeks and am currently scratching my head. I bought it off of a farm in Missouri. They said they parked it 3 years ago and everything was working at the time. Then when they tried to get it going they couldn't. So now I am part of the tractor world.

When I got it home and did a compression test, one of the cylinders had no compression, one half and one full compression. I took of the head and one of the valves was burned up. I took the head to a local machine shop and had them do a valve job. The cylinders looked great, no scratches or obvious problems.

We put it on with all new gaskets and checked the compression... it was up to spec. It started right up. I let it run for 30 seconds or so and then shut it off because the hydraulic fluid was leaking in some of the hydraulic rams. Now when I try to start it the solenoid engages and the starter attempts to turn. Thinking it was a bad starter, I bought another. Turned out the right starter was twice the size of the old one. Still, same problem and the starter is still heating up. Then I took the oil pan out and took off the valve cover. Whenever I try to start the engine, everything moves slightly. I then took off the hydraulic pump in case this was preventing the engine from turning. Same problem, but I was able to verify that the crank shaft also moves slightly. At this point I think I can move the engine through its full range of motion a little bit at a time (this would take a long time since I would have to give the starter a chance to cool down every 10 attempts).

BTW: We also took out the spark plugs on the off chance it was some sort of compression thing stopping the motor. The new spark plugs still looked new. Also, when we drained the new oil, there were no metal flakes.

Every time I try to start it, I push the clutch in.

However, at this point there are several possibilities that I know of. Maybe the transmission is preventing the engine from turning. The oil pump is also still attached. Could this be preventing the engine from turning? If there is a foreign object wedged between moving parts, could manually turning the engine backwards unbind it? Has anyone experienced this type of problem? Any idea what could cause it? Would splitting the tractor be the best way to remove the transmission from the equation?

Let me know if you need pictures, video, or more information.
 
Take a look at the hydraulic pump .. On the front cover look for a Tee handle sitting straight up.. Turn the tee handle clockwise till you feel a slight tightness , then turn another turn.. This unloads the hydraulic pump so it is easier to start.. Once it starts , turn the tee back out till it stops.. If it starts now , there might be a problem with the pump valving..
 
I disconnected the hydraulic pump from the crank shaft to make sure it would not interfere with the engine turning.
 
I find it hard to believe the engine clutch is
stuck AND the trans is seized - all at the same
time. I was a Deere mechanic for a long time.
Can't say I've ever seen that happen on a
Dubuque tractor. You said you disconnected
the hydraulic pump and still no good, correct?
What happens when you try to turn the engine
over by the flywheel with a screwdriver?? Rock
hard to turn? If so I'd suspect a spun/galled
main bearing. Did you find any coolant in the
oil-pan when you pulled it off?
 
The hydraulic pump is totally disconnected from the engine. The flywheel can turn with difficulty. Also, the oil I recycled was clean.
 
(quoted from post at 19:36:50 10/07/14) Sounds like an insert piling up.


So a piston would be stuck? Correct? And trying to pull the sleeve up with it?
Do you have a good way to find out which one?
 
(quoted from post at 20:02:05 10/07/14) 1976 John Deere 300b Backhoe Loader (Industrial)
1020 CID 135 Gas Engine (Deere, 3 cylinder)

I've been working on this tractor for a few weeks and am currently scratching my head. I bought it off of a farm in Missouri. They said they parked it 3 years ago and everything was working at the time. Then when they tried to get it going they couldn't. So now I am part of the tractor world.

When I got it home and did a compression test, one of the cylinders had no compression, one half and one full compression. I took of the head and one of the valves was burned up. I took the head to a local machine shop and had them do a valve job. The cylinders looked great, no scratches or obvious problems.

We put it on with all new gaskets and checked the compression... it was up to spec. It started right up. I let it run for 30 seconds or so and then shut it off because the hydraulic fluid was leaking in some of the hydraulic rams. Now when I try to start it the solenoid engages and the starter attempts to turn. Thinking it was a bad starter, I bought another. Turned out the right starter was twice the size of the old one. Still, same problem and the starter is still heating up. Then I took the oil pan out and took off the valve cover. Whenever I try to start the engine, everything moves slightly. I then took off the hydraulic pump in case this was preventing the engine from turning. Same problem, but I was able to verify that the crank shaft also moves slightly. At this point I think I can move the engine through its full range of motion a little bit at a time (this would take a long time since I would have to give the starter a chance to cool down every 10 attempts).

BTW: We also took out the spark plugs on the off chance it was some sort of compression thing stopping the motor. The new spark plugs still looked new. Also, when we drained the new oil, there were no metal flakes.

Every time I try to start it, I push the clutch in.

However, at this point there are several possibilities that I know of. Maybe the transmission is preventing the engine from turning. The oil pump is also still attached. Could this be preventing the engine from turning? If there is a foreign object wedged between moving parts, could manually turning the engine backwards unbind it? Has anyone experienced this type of problem? Any idea what could cause it? Would splitting the tractor be the best way to remove the transmission from the equation?

Let me know if you need pictures, video, or more information.
 

I have the same tractor/backhoe and experienced the same problems with starting. New batteries, new starter (tried two new ones), new cables, etc. Finally discovered the ground battery cable was attached to the sheet metal behind the engine and was not making good contact to the engine ground. I believe it was run this way from the factory.

I ran a new heavy cable directly to one of the starter mounting bolts and it instantly solved the problem.
By the way, I also installed one of the new geared starters and it is amazing how much faster it turns the engine over. It did interfere with the mechanical fuel pump and I had to get a different one.
 
If so I'd suspect a spun/galled
main bearing. (reply to post at 19:07:21 10/07/14)

Sounds like an insert piling up.(reply to post at 19:36:50 10/07/14)

Sounds like a basic engine block rebuild may be in order. I found the following kit and bearing. Hopefully these will do the trick.

http://www.yesterdaystractors.com/John-Deere-1020_Basic-Overhaul-Kit-135-CID-Gas_BEKD4442LCB.html

http://www.yesterdaystractors.com/MS873AL_Main-Bearing-Set-135-Gas_8281.htm
 
You will need to get the crank ground (if it is still grind able) before getting the bearings so you get the right size.
 
Need to determine just how hard the engine is to turn. With the plugs out you should be able to turn it by hand by turning the crank pulley or the fan, holding the belt tight. If so, the problem s still with the starter, battery, cables or solenoid.

If you determine the engine is indeed seized, start looking for the problem. Look at the color of the rod caps, if one is dark, pull the cap and look at the bearing. The rods should have some side to side play on the crank, easy to feel just by pushing with your fingers. Same with the main bearings, look for color differences, start pulling them and looking at the bearings. There should also be some end play in the crank, not much but a clue if it is seized or not.

Could be a seized piston, not likely since it was running, but worth checking. Remember the side to side play in the rod? Hold turning pressure against the crank, see if one of the rods gets tight and won't move side to side. If so that piston is binding.

Just a matter of searching until you find the problem. Start removing accessories like power steering pump, oil pump, anything that turns with the engine.
 
You ought to pull some parts out and inspect
before ordering parts. If the engine has a
spun or galled main bearing and it just
happened - you might be able to repair without
pulling engine and crankshaft out. I've fixed
several over the years that seized a main-
bearing from coolant in the oil. Often happens
to an engine that's been in storage and then
started. Seals on the sleeves leak a bit and
water gets in the oil-pan. After sitting and
then starting - oil pump picks up the water and
sends it to a main bearing - and then the main
bearing acts like a brake-band. If caught
before run too much - it's possible there is
little to no crank damage. Just have to clean
off any soft-metal transferred from the bearing
shell to the crank journal. Sometimes after
cleaning the crank-journal with crocus-cloth -
you might want to install a slightly undersize
main bearing. Deere used to sell .002" under
mains just for this purpose. Might still find
them aftermarket since Deere no longer carries
them. AT21130 and AT21108.
Keep in mind that early 300s had only one seal
per sleeve when new and were prone to leaks.
When rebuilt and upgrade kit was used with
three-seals per sleeve.
 
water gets in the oil-pan(reply to post at 06:00:52 10/09/14)

When I first got the tractor and changed the oil there was at least a quart of water in there. The flap on the exhaust was open so I assume rain came in that way.

oil pump picks up the water and
sends it to a main bearing - and then the main
bearing acts like a brake-band. If caught
before run too much - it's possible there is
little to no crank damage.(reply to post at 06:00:52 10/09/14)

After we did a valve job and got the tractor running, it ran for about 30 seconds before I shut it off. How do you get the bearings out without removing the crankshaft? Also, is there any possibility the power stearing pump or timing chain could bind up the motor?
 
Here's what happened with the tractor. The oil pump is broken along with the gear and shaft. The first piston I took apart has a spun rod bearing.

So we need rod bearings and rings....i think the crank is okay...just needs polishing by hand. Plus a complete oil pump assembly with gear.
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