Letter codes

It sure sounds like you have a ZA series tractor, in particular a ZAU by your description of the front tires and the grill. The 206-4 engine you have was made for the ZA's. If you change that 6 in your engine number to an 8 (making it 01817357) then that would fall in line with a 1952 206B-4 engine, which ranged from 01812820 to 01818924. The range of serial numbers for a 1952 ZAU is 00609940 to 00614658. Take a real close look and see if you made a mistake on your tractor serial number of 0031627, I think you did. The fact your serial plate just has a Z for model tells me it is a ZA series, as a ZT series tractor would probably have ZTU stamped in as the model. You can forget about your tractor being a 1930's model ZTS. Hope this helps.

Jim

I suggest you take a closer look at your tractor serial # plate. There shouldn't be any spaces in the #.

Brian

Is the grille a screen affair in a rounded hole or is it horizontal bars? ZT tractors used the screen in the rounded hole, ZA tractors had horizontal bars.

Is the rear wheel tread adjustable with the wheel hubs clamped to the axle or are the hubs held on with a great big nut on the axle? ZTS and ZAS used the nut on the axle, All others clamped the hub to the axle.

Does the gear shift lever go down into the center of the top of the transmission cover, or does it make a 90 degree bend and go into the right hand side? ZT tractor gear levers make the 90 degree bend, ZA tractors go down into the center of the top.

Does it have a wide non adjustable front axle, 1 front wheel or a 2 wheel narrow front?

In case it might be a '39 Do the wheel rims clamp to cast iron centers or do they have sheet steel disks that bolt to the hubs. Lots but probably not all '39s clamped to cast iron wheel centers.

Clamped rear wheels on long axles, could easily take dual rears.

Gear shift goes straight down into the top of the tranny.

Brake drums are ahead of axles on the outside of the frame case and inside covers. Rear PTO cover is a half cylinder not a rounded wedge shape.

I have seen three types of 2 wheel fronts, one is fixed width and narrower, the second is wide and appears adjustable, and mine which is very narrow and the two wheels are angled inward at the bottom in a vee.

The wheel centers are bolted, or riveted to the rim. I don't know which. They are steel and slightly curved with the offset at the edge of the rim.

The battery is behind the hydraulic reservoir and under the fuel tank.

No decals on the tank, just on the cowl with an additional circular decal to the right of the long one. I can see a bit of the Minn Mo on the long decal on one side but nothing in the circle is legible.

Multi-position light and ignition switch with push button start. Gauge cluster has ammeter above temp on left lower with pressure to the right of it.

From all of what you said I think it is a ZAU but the 0 031 627 frame number gives me no clue to assembly date.

It is possible I mis-read the engine number as 161xx when it shold be 181xx. If so then the engine number comes out 1952.

Brian