1937 unstyled A

[Wes g]

I’ve got a 1937 unstyled A that I’ve been working on. Ive turned the flywheel with the engine apart when it’s just the flywheel and crankshaft left to turn. When I’ve turned the flywheel about 3/4 of the turn feels normal but around 1/4 of the turn it feels tougher to turn it but then feels normal once it’s through that part. Anyone have an idea what this might be?

 

[a49deere]

Did you have engine apart, crank out? Your description is confusing! Are you just turning crank or crank and pistons and valve train? If just the crank it sounds like your clearances are too tight on the crank main bearings that may be slightly oval!

 

[Wes g]

Sorry I didn’t write it well. Engine was apart and I was just turning the crank. I did think that maybe it could be main bearings but would be confused on why it’s only one part that’s tough when I turned the crankshaft a full rotation.

 

[matthies]

Is the camshaft or governor still on?

 

[Wes g]

Camshaft is on, I’ve taken the governor off.

 

[matthies]

Camshaft bearings or tight lifter?

 

[Fixingfarmer]

Check your mainbearing clearances on the crankshaft I’ve seen a bent crank do some of what you describe as a tough spot in EVERY rotation of the crank if I understand that correctly. That is the rotating assembly I’d be looking at closely at least to start with.

It can be difficult to tell if you have a bent crank with it in the tractor and usually the 2 cylinders loose the splines off the crank first…

Unlike the later tractors there won’t be any shave a bit off the side of the main cap to make it go either I’m afraid you will be looking for some good pieces

 

[Wes g]

Ok, i can try to check clearances. I was gonna buy a 70 I worked on that got to expensive but if the crank is bent in this A… Thankyou for your help!

 

[Wes g]

Does anyone know where I could get some extra/very long spark plugs? Got some hi compression inserts and am looking for extra long spark plugs that’ll keep them from spinning.

 

[used red MN]

I’ve got a 1937 unstyled A that I’ve been working on. Ive turned the flywheel with the engine apart when it’s just the flywheel and crankshaft left to turn. When I’ve turned the flywheel about 3/4 of the turn feels normal but around 1/4 of the turn it feels tougher to turn it but then feels normal once it’s through that part. Anyone have an idea what this might be?

If the crank you have in there is used and not reground another thing that can cause that is the journals are worn “egg shaped” You set the clearance at the narrower part of the egg then turning it the wide part it gets to tight in the narrower dimension of the bearing shells.
Edit: Probably more likely to happen on the rod bearings.

 

[HFP]

If you have to put a crank in it, I'd look for a mid-year (41-46) and get that extra 1/4" of stroke.

 

[a49deere]

If the crank you have in there is used and not reground another thing that can cause that is the journals are worn “egg shaped” You set the clearance at the narrower part of the egg then turning it the wide part it gets to tight in the narrower dimension of the bearing shells.
Edit: Probably more likely to happen on the rod bearings.

What I got from OP was he was turning crank without the rods connected. So that would at least rule this out.

 

[Wes g]

Ok, that problems been solved. Does anyone know where I can get a book/service manual for my 1937 A?

 

[Fixingfarmer]

Ok, that problems been solved. Does anyone know where I can get a book/service manual for my 1937 A?

The John Deere publications website has a free download of publication number DIR103 for an unstyled model A

It’s one of my favorite operators manuals only 32 pages but it’s very informative on how a 2 cylinder operates and what it takes to fix and I’d suggest printing it off it was the only manual they had back then

What it COMPLETELY lacks is torque specs. It will say tighten head bolts till snug (those must have been the days!) At least the B version DIR103 I have does.

I’ve had mixed success but there are other brands that are sold on this website of service manual.

What I do is search for specific torque specs (head studs) on this website and if there isn’t one then it’s standard torque off the John Deere chart based on grade of fastener and taking it easy on small bolts going into cast radiators.

I have to look this info up anyway if using a different manual to double check so that’s what I’d do.

 

[a49deere]

Ok, that problems been solved. Does anyone know where I can get a book/service manual for my 1937 A?

what did we find was the problem?