Reviving a D7E 48A

Just got a "new to us" 48A going a month or so ago. Pony magneto is pretty simple if you carefully remove the cap screws, you will be looking at the rotor button and the points are underneath. BE CAREFUL WITH THE CAP! There are 3 spring-loaded carbon brushes in it that can be broken or stuck. They should protrude under spring pressure and push in easily with a finger. When you reinstall the cap, make sure to push it on straight and not let it get cocked to one side so the brushes push straight into the sockets.

Operator's manual should have a section on the pony magneto points setting and how to time it to install it. We had 3 old mags on the table and found enough good parts in them to make one. If you have the mag off the tractor, you can turn it by hand (glove helps, sort of tough on the fingers) and the impulse will wind up and trip with enough force to throw a good spark of everything is right. If you turn the mag backwards it won't wind up, it'll just turn smoothly, that's the easiest way to get it aligned to reinstall. Should be an X on the drive tang and another on the socket for it in the tractor gear. 2 bolts and a gasket and you're good. #1 cylinder is to the front of the tractor, but I cannot remember which way it rotates. I would watch it as you crank the pony over with the cap off. The pony is an "odd fire" type so the mag should have 2 sparkplug wires next to each other on one side of the cap and 2 blank spots on the opposite side (total of 4 spots where there could be wires put in the cap, but two blanked off)

I ended up cleaning the carburetor, but really my problem was that I had a sparkplug fouled out. Carburetor is pretty simple, one joint with a gasket between top and bottom halves. After cleaning all the passages with compressed air, wire, drill bits etc, I made a new gasket and reassembled it. I used 1 turn open on both idle and load mixture screws as an initial setting to start it. Except for the fouling plug (pony uses a lot of oil), it has been a really reliable starter. The fuel tank is plated inside and didn't have the handsfull of rust I am used to dealing with on old CAT pony motors. There is a sediment bowl under the tank and the gas valve is on the right side of the dash panel of the tractor. Ours will screw the cap off the shutoff valve if you open it too many turns. On ours a single turn open is plenty of gas to run it.

The drain valve for the pony oil is a 3/4" bolt head accessable through a hole in the frame next to the pony oil pan. Open it and the oil will drain from a hole in the belly pan. I would spend a few minutes underneath with a 3/4" breaker bar or ratchet and perhaps an extension to check each compartment for water and metal. You may get a bit oily and waste a cup or two of oil, but you can remove any water and get some idea about the condition of whatever component you're sampling the oil from. A few clean cups or something like that to catch a sample from each work great. It's a lot easier to get to under that tractor than the smaller ones! Be ready, you have a lot of oil above each plug, if you loose the plug or it gets off center in the hole, you'll likely get a bath!

Fuel tank drain is underneath the left side of the tank accessable from a removable plate there at the back of the tractor. Should be a 3/8 or a 5/16" square stem on the valve. Might get rid of some trouble draining condensation and sediment before you suck a lot of it into the pre filter and the filter housing. Follow the line along the right side of the tractor frame and you'll see the pre-filter cannister with a screen in it and then the filter housing has two filter cartridges in it. There is a large bolt on the bottom of the housing that is the drain to drian the filter housing completely and get rid of any sediment and water that have collected in there (or grown there!). Pour the clean filter housing nearly full of clean fuel, install the filters and button it back up. Crack the bleed screw on top and once you get the pony turning, it'll quickly purge all the remaining air. Start it turning with the main engine throttle closed unti you get it bled out and the main engine warmed up from the heat of the pony motor turning and the heat of compression in the cylinders and when you open the throttle (pull it toward you), it will most likely fire right off.

Thanks for the help guys! I am about to hit the road with a car full of tools, so I'll let you know how it goes.

The old girl lives! We started on it about 7:30 on Saturday and had it running by 10:00 or so.

We double checked the pony motor with a compression tester just to make sure we weren't wasting our time; also changed the oil which was pretty thin and smelled like varnished gasoline. All it took to get spark was filing the points with an emery board; we wire-brushed the spark plugs, dumped some gas in and it started right up. Pony seems to run great, just a hint of choke to get it started cold but doesn't need any choke to run and sounds healthy. We cranked the diesel over for a while with the pony transmission in low gear until the oil pressure came up; once we shifted the pony into high gear and opened the throttle it pretty much fired right off and seems to run great.

Most of the fluids were OK, if not a little overfull from condensation. The final drives and transmission could use a top-up but weren't too bad. The cooling system must have been about dry; it took 15 gallons.

Everything seems to work fine, with the exception of a blown hydraulic line for the blade tilt. We ran it around the yard a little bit, then shut it down and spent a half hour going over it and greasing every zerk we could find. We have a couple of fairly large dirt piles from digging out the foundation, so afterwards we pushed a little bit of dirt around with it; I think it will push a lot better once the blade tilt works - it just sort of floats around right now.

The next project will be to get all the fluids changed, since I'm sure there is water in everything. Any tips on part numbers/sources for various filters (transmission, oil, fuel, etc.)? One drain plug I haven't yet found is the transmission for the pony motor, which is showing quite overfull on the dipstick - can anyone point me in the right direction here?

I managed to break the knob off the fuel shut-off for the pony motor (fortunately in the open position). Is this a readily available part, or would I be better off just plumbing in an inline filter and shutoff valve?

Thanks again for the help! I've attached a few pictures so you can see the machine in action.

Nice looking tractor! thats a 180HP engine. keep the pony on it and maintain it good and will run great forever. Whats the serial # ? I have a 48A12342 D7 Where you located?

sorry i forgot you listed the info above. The first 180HP was after 48A6883, I also have a 48A6864 160HP.

Your tractor should be a late 1966 or very early 1967.

Isaac,

That is a really nice tractor. I'm jealous! Wish I had it and some work to do with it. Can't say as I've ever seen a 7E with a cable blade. That must have been one of the last produced. I love cable particularly with the hydraulic tilt. Best of both worlds as you can cut into hard pan with the corner so the cable blade will bite better. Have fun with it!

Jan, CAT 15 PV 7207 in process of restoration

You can over grease the water pump real easily. One or two pumps will do. Check to see that the water pump has a relief valve and that someone didn't replace the relief valve with a second zerk. I don't know but this was a popular modification that wrecked many a water pump.

Pull the floor boards. She should also have a double u-joint between the torque converter and transmission that's called a drive line which needs grease every 500 hours or so.

I hate that fuel valve on the pony. I was always going to plumb in a ball valve. I think OM mentioned using ball valves in a fuel system before. We don't use our 48A anymore or I would have some info on this.

As for fluids, nothing is cheap anymore. You might think about using CAT products as I no longer believe the engine oils we used in the transmission in years past will do the job any longer. That Cable Unit probably needs some attention too. Hopefully someone will jump in here and tell you what to do. I've never played with one. Hope this helps.