Installing Water Temperature Guage on TO-20

I’m looking to install a water temp gauge on my To-20, I see a bolt in the water neck left side by the upper hose, is that where it goes? Is there a certain brand you recommend? July 11, 2015.

Yes, that plug on the side of the water outlet is where the temperature gauge bulb goes. I worked with Steiner Tractor Parts to get a reproduction of the original gauge made. The link below shows that gauge, it’s Steiner Part Number ABC1593

There is also a very good gauge available from Stewart Warner. I have a NAPA part number for it if I can locate it, but it’s about double the price of the Steiner gauge.

When you remove the plug be careful to save the gasket. You can use the round brushes they sell for cleaning the bores of copper pipe fittings to clean out the hole in the water outlet so the temperature bulb will seat properly. Some of the early Z120 engines had a clearance problem when it came to mounting the temperature gauge bulb so Ferguson produced an adapter that fit in the hole using the original plug gasket. The temperature gauge bulb then would fit into the female end of the adapter. The last I knew those adapters were still available as NOS parts but a bit hard to find today. The adapter was primarily for the TE-20 but I have found they are sometimes needed on TO-20’s, and even TO-30’s.

They used the same clips used for the tractor light wiring harness to attach the capillary tube that goes from the temperature bulb to the gauge to the side of the block. Those clips are available from Dennis Carpenter Ford Tractor Parts as Ford Part Number 9N-17668. I believe they used 3 on the cylinder head bolts along the left side of the block, and 1 under the battery tray.

Remember to torque the cylinder nuts after you install the clips. Do the center one first and then the front and back. You’ll need a screw and nut and a washer to attach the remaining clip to the bottom of the battery tray. I have the original instruction sheet somewhere in storage. I’m hoping Jeff Miller, one of our FENA members who I am sending this to, has a copy and can scan it and send it to you.