JD 50 rod bearings assembly

[chas036]

My 50 that I bought at an auction in september has continual blue smoke comming out the stack when operating. I did a compression check and both cylinders are 90 to 95 lbs. It was not run for 3 o 4 years when I got it, so I am thinking the problem is either the valves or oil rings being stuck. My question is ...has anyone disconnected the rod bearings without removing the oil pump? I can see the cover to the crankcase behind the oil pump, but I just can't see how you could get your hands and wrenchs in there to loosen and remove the rod bearings without removing that oil pump assembly. When I read the service manual , it said nothing about removing that pump assembly to get to the rod bearings.

 

[MSM]

My 50 that I bought at an auction in september has continual blue smoke comming out the stack when operating. I did a compression check and both cylinders are 90 to 95 lbs. It was not run for 3 o 4 years when I got it, so I am thinking the problem is either the valves or oil rings being stuck. My question is ...has anyone disconnected the rod bearings without removing the oil pump? I can see the cover to the crankcase behind the oil pump, but I just can't see how you could get your hands and wrenchs in there to loosen and remove the rod bearings without removing that oil pump assembly. When I read the service manual , it said nothing about removing that pump assembly to get to the rod bearings.

Before you tear into it, is the crankcase over full with gas from a leaking carb? Is the fuel clean?
I worked on a 60 a while back that the owner mistakingly dumped a couple gallons of diesel in the tank with with some gas that was in it. tractor started and ran fine, but smoked terribly.
If the oil isn't diluted, take the tractor out and run it hard with a load for an hour or so and the rings should free up, if that is the problem.

 

[MSD]

Every other 2 cyl you can get the rods loose without doing anything to the oil pump. Turn the crank so the top of the rod is at the top of the crankcase and loosen that one. You might have to turn it a little one way or another to get to both of them. If you want a challenge try getting them loose and back in a 10 inch stroked G once.

 

[chas036]

Before you tear into it, is the crankcase over full with gas from a leaking carb? Is the fuel clean?
I worked on a 60 a while back that the owner mistakingly dumped a couple gallons of diesel in the tank with with some gas that was in it. tractor started and ran fine, but smoked terribly.
If the oil isn't diluted, take the tractor out and run it hard with a load for an hour or so and the rings should free up, if that is the problem.

The gasoline is clean. I have the gas tank off the tractor, and I am using a one gallon can I rigged up with an outlet at the bottom of the can to supply gas to the engine. Also I have changed the oil and filter. I have let the tractor run for about 30 min straight, but nothing under load yet, but I will try that this spring when the weather is warmer and I can get out into my fields where I can go up hills to put a load on it.

 

[buickanddeere]

Run it with straight weight 40 oil , the coolant at 195F and the both idle and mains on the carb set lean .
Then get back to us.

 

[matthies]

He must be talking about the hyd pump not the engine oil pump. Since you have the fuel tank off, it would be easier to just pull the steering pedestal/gear selector housing to get in there. Then also clean the crankcase while you have it open, you will be surprised at the crude that is in there. The hydraulic lines can be a pain to get out of the hyd pump, and the gasket usually needs replacing under the pedestal.

 

[chas036]

He must be talking about the hyd pump not the engine oil pump. Since you have the fuel tank off, it would be easier to just pull the steering pedestal/gear selector housing to get in there. Then also clean the crankcase while you have it open, you will be surprised at the crude that is in there. The hydraulic lines can be a pain to get out of the hyd pump, and the gasket usually needs replacing under the pedestal.

Yes , you are right, it is the hydrualic pump, not the oil pump. My mistake.

I never tought of taking off the gear selector pedestal. I guess disconnecting the wires from the gauges , is a lot easier than disconnecting the hydraulic lines.

With respect to sludge in the crankcase, when I went to change the oil, it would not drain because of so much sludge clogging the drain hole. I had to insert my finger and pull out some sludge before the oil would drain out, so I can imagine how dirty that crank case is. Thanks for the advice.