420c

[Anonymous-0]

I have a John Deere 420C year unknown. The motor was weak when I bought it. I was letting it lug coming up a hill when I heard a bang and it stalled. It turned over about 1/2 a revolution then stopped and wouldn"t turn over any further. There are no obvious holes in the block, and no water in the oil. Up until now I assumed I had thrown a rod. Here"s my problem, It sat down the hill for about a month before I could get someone in to pull it up to my barn so I could start work on it. When we pulled it up the hill both tracks would not roll as it was pulled. They just skidded along as if the brakes were on, they weren"t. The trans was in Neutral and the reverser was in Neutral. Any ideas or help would be greatly appreciated.

 

[FDBYRD]

The 420 was made 56-58. I have a 57. The reversers in these are junk. I have had mine for over 15 years. Most people I have talked with have removed them, as I have mine. They have clutch packs in them that will lock up. This sounds like it is your problem, not the motor.

 

[Anonymous-0]

If the engine won't turn while the clutch is in then you probably have a camshaft timing problem or broken camshaft. If it will turn then it is in the drive train. The tracks are hard to move by towing because of the gear ratios, so that is no surprise. You might try turning the engine and watching the rotor. If the rotor doesn't move then the camshaft problem is confirmed. If the valve timing is off you can do some pretty heavy damage turning the engine.

 

[Anonymous-0]

Thanks guys, In reply... The reverser had some bearing noise in reverse so I stopped using it and shifted w/ the trans only, which worked fine. When it "stalled" I tried to restart it. The motor turned over about a half a turn then stopped. The motor won't move at all now. I can't find a bolt/ or way to turn the motor over by hand or back it up even. The front of the crank appears to have a fitting on it I can only assume is for a hand crank. Since I don't have a hand crank, is there another way to spin this motor over to isolate components? I assumed that since the tracks were dragging I may have some sort of failure in the trans as well or instead. Thanks for the help.

 

[Anonymous-0]

If it won't turn a little at a time backwards with a screwdriver thru the timing hole then don't do anything until you pull the head (it's easy).

 

[Lavoy]

Very few 420's had a clutch type reverser. Only the 420's built after 131,309 had a clutch type reverser, so potentially less than 1000 crawlers. The reversers were fine if operated correctly, if not, then not the fault of the reverser. I hate to say it, but I wonder if you broke the crank. Pull the pan and check for sure. Coming to a sudden stop is not something that is going to be a simple fix, just as well determine what the problem is.
As to the track skidding, could be the brakes stuck from moisture. If you can turn the engine over with the clutch pedal depressed, but not with the clutch pedal out, then it could be trans trouble that is causing both problems.
Lavoy
JDCRAWLERS.COM