Sunday, March 15, 2009

It’s been a couple of weeks since I’ve posted anything. Mainly because about two weeks ago I had an Oh-S___ moment and wanted to be sure I could effectively recover before I wrote about my event and the outcome. For those reading this just because, the next few paragraphs will be about as exciting as watching grass grow. However, for those of you truly interested in the mechanics of these old tractors, you might learn something.

I was working on the lift cover to clean it up in preparation for painting. At the front of the cover, approximately centered, is a threaded plug covering the bore for a check valve designed to hold oil in the lift cylinder and to hold the arms in a raised position. If this valve is not working properly, the arms will not raise or will be jerky when they do raise. The valve can be seen from the underside of the lift cover, through the ports in the cover.
This particular valve would not budge when I tried to move it using a screwdriver as a lever. As a matter of preventive maintenance, I decided to service this valve and clean up the bore in which it moves. I had performed this service on a couple of previous lift covers, with good success.

While the service manual gives instructions on removing this valve, a great video, titled Hydraulic Repair for Ford Tractors available from J & D Productions, Inc., Metamora, MI, provides the most practical method of removing this valve, using a fine threaded 3/8” bolt and moving it incrementally with the continued addition of flat washers. These particular shuttle valves have three spools, a hollow shaft, and a port in the shaft between two of the spools with an O-ring around the largest spool for an effective seal. The shaft is threaded up to the port allowing a bolt to be screwed in for removal.

Removal of this valve was pretty straight by the book and it came out with little difficulty. After cleaning it and replacing the O-ring, I lubed it and re-inserted it into its bore. This time instead of screwing the bolt into the shaft and tapping it in using the bolt, I used a piece of 5/8” steel rod to drive it in. It has to be driven in since there is a slight constriction in the bore to, I presume, limit forward movement when the valve is doing its job. It went in with difficulty and, once in place, still would not move in its bore. Obviously I had not either polished it sufficiently or cleaned up the bore enough. When I repeated the process to remove it, I thought it came out too easily. When I pulled out the bolt, however, the only piece that came with it was the first spool. I had broken the shaft right at the port. Those valves are hardened which also makes them brittle.

That was my O-s___ moment! The remaining two spools on a hollow shaft with no threads was still stuck quite tight in the bore. It was positioned right over the ports in the cover without any way of moving it through those ports. How in the h___ was I going to get the remainder of that valve out? Although I had a spare lift cover, I didn’t want to go through all the work of removing the linkage pieces from this cover and putting them in my spare and then having to junk what was otherwise a perfectly good lift cover.

I sent an e-mail to my friend and tractor restoration mentor, Ron Kingland, explaining my dilemma. He called me the next day to offer some advice. He had the same thing happen to him sometime ago and was successful in removing the remainder of the valve using a 5/16” concrete anchor. When neither of us was certain that I could locate the same type of anchor he had used, he agreed to send me a couple of them. Several days later, they arrived in the mail. In the meantime, I had cut, drilled, and tapped a short length of 5/8” steel rod to serve as a coupler between my slide hammer and the concrete anchors.

That evening I went to my shop with some trepidation, hoping this would solve my problem. Driving the “nail” that serves to expand the anchor at its base, I attached my coupler and, using the slide hammer, began the attempt to pull the remaining valve piece out. I found that I could move it, but it wouldn’t move past the slight constriction in the bore. The slide hammer pulled the anchor out of the shaft every time. Now what? With a flashlight, I could see that the bore in front of the valve section was crusted with rust and other crud from years of little use. I tried wrapping a piece of sandpaper around a drill bit to polish up the bore with little success.

Another call to Ron. This time he suggested using a small flap wheel to clean up the bore. Unable to find any that small (the bore is approx. ¾”) I ordered three from Shipping was prompt and a couple of days later, they arrived. These flap wheels have a 1/8” shaft allowing them to be used with a Dremel type rotary tool. I had previously purchased a flexible extension for my Dremel and used that to enable me to insert the flap wheel further into the bore of the valve than would have been otherwise possible using just the Dremel. I polished that bore in front of the valve until it shone, then cleaned it up with brake cleaner and some paper toweling wrapped around a dowel. Then I inserted one of the concrete anchors once more and set it in place. After spraying the bore with WD-40, I attached my slide hammer and began removing it. I breathed a sigh of relief when, this time, the remainder of that valve emerged from the bore. I couldn’t have been more pleased.

Tuesday, February 17, 2009

Not a lot of progress on my Ford 740 project last week. I managed to split the transmission from the rear section, remove the PTO shaft and replace all the seals including the seal between the hydraulics and the differential. I also separated the hydraulic lift cover from the rear section to inspect the piston and linkages. There is a pin in there that routinely wears from riding on a large cam when the lever to lift and lower the arms is moved. I wasn't disappointed; it was worn almost in half.

It didn't appear that the PTO seals had ever been replaced before. All the existing seals were original Ford brand seals and the gunk on the bottom of the hydraulics section was thick and gooey. Probably a combination of hydraulic oil and 50 years of accumulated dust that manages to sneak in. I had a little moment of panic as I was raising the rear section with my engine lift to position it better to insert the seal that fits between the hydraulics and the differential. I still had the rear wheels mounted and, as I lifted the rear section (hydraulic sump and differential), the weight shifted and it started to flip over backwards. Fortunately, the engine lift remained attached so it didn't get far. I had to hook on a come-along to pull it back up and over into its proper position.

Most of Saturday afternoon was spent waiting for the guy who wanted to look at the one tractor I had for sale. Fortunately, he did eventually show up and the sale was consummated.

A good part of Sunday was spent cleaning up bolts for eventual painting when I re-assemble the pieces. This process is done with a wire wheel chucked into a 3/8" corded drill. I do this outside as the wire wheel throws pieces of dirt and rust everywhere. It's slow and tedious work but I do it with all the bolts to get rust and grime out of the threads and clean up the bolt heads and nuts. You need clean threads to get the proper torque and the bolt heads and nuts just look better if they've been cleaned. I've seen paint jobs where it's obvious nothing was dis-assembled and the new paint was applied right over gobs of dirt and grease. Tacky, tacky.

Monday, February 9, 2009

Tractor restoration

This blog will be a journal of my progress with tractors in my restoration queue. I am currently working on a 1956 Ford 740 and have a 1959 Ford 641-D in my shop waiting for its turn. The 740 has been sodablasted ( and is currently being completely disassembled for painting.

It's at this point that I replace any worn parts such as bearings and seals. I'll also pull the head off the block to take a look at the valves and pistons and remove the oil pan and one or two bearing caps to check the wear on the piston and main bearings.

I do this as a hobby working evenings and weekends as I can find time away from my day job. I'll update the work on this tractor from time-to-time as I make progress with it.

I also have a 1959 or 60 Ford 841-D that I'm trying to sell, completely un-restored. If it doesn't sell I'll put it in the queue for a restoration project, too.

Thanks for checking in!