Oil return

   / Oil return #1  


New member
May 15, 2023
1959 530
We have a 1949 model a and wanting to know how the oil returns to the crank case. We don’t see a return hole or slot


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   / Oil return #2  
John Deere Co. published some remarkable books that enabled people to fix their tractors at home.

Your question made me curious, so I looked at some of my old JD service Manuals:
SM2000: Engines and Tractors
SM2008: Model 60 Tractors - Which is a little later A, but very similar.
Plus Operator manuals for some old 2 cylinders

But in none did I find a definite answer to your question. A lot of motors from that era didn't have a dedicated hole or slot to return oil to the sump. Instead they relied on gravity, clearances, and the fact that most of the inside of the motor housing is simply empty space. For example, oil is pressure fed to the crankshaft mains with great care, and after lubricating the main bearings it exhausts onto a slinger - which I guess is how the seal face gets lubed....but then nothing more is said. My assumption is it drips into the sump and the same sort of arrangement is true for the rocker assembly lubrication. There are sometimes in some models special oil lines that lead to areas where special features like bevel gears are lubed - but not a word on how the oil returns.

Whatever the case, the oiling system sure works very well. After some 40 years of hard work - and many thousands of hours....including a decade of work as an pto irrigation pump in a corn field.....
I just couldn't resist opening up my own old two cylinder B to bring it up to new spec. What kicked the project off was one day the tachometer needle just fell over sideways inside the gauge. When I opened up the tach for a look, the bushings inside were worn completely oval. A new OEM tach complete was less than $100. but what did that mean for the engine?

To my surprise, once inside the engine, everything I measured was just fine. Cylinders were perfect & not even any taper or ovality in the bore. The mains and rods were within tenths of new...in fact everything inside was within factory tolerance for a new engine. I put in new gaskets, did a minor valve job, rings, lapped the head, and reassembled. Absolutely no difference from before. I felt lucky and a bit foolish.

Hope yours goes as well. I will say that extended sitting with this new gasoline with alcohol has give it a few carburetor problems... and replacing the spark plug wires & associated parts made a definite difference. But other than that, it has had little maintenance.