Ford 640 swinging draw bar install troubles

[Neil.640.105091]

I am having a hard time finding what the
correct bolts to mount the under belly
bracket for a swinging draw bar.
In addition to that, I was disappointed to
discover that someone along the way had
sheard off 3 out of the 4 bolts. So I'm
also curious to know if I cant get the old
bolt extracted, would it be ok to use a
helicoil?

Thanks

 

[showcrop]

Well, you have a tough one there! yes you can drill and use a helicoil, but one usually goes in an order. working upside down will make it challenging, but the first try should be welding a nut to the broken off bolt still in the hole. grind it flush first, then set up a means of holding the nut tightly up against it while you weld the nut to it. If you can't get that to work the next try should be a left handed drill bit and extractor. NOT an Easy Out. The left handed drill bit is vital. Use one of the square tapered ones. alternate trying the extractor with applying heat. heat the bolt cherry red then let it cool. The bolt will heat up much faster than the housing which will be getting cooled by the oil, If you are unsuccessful with the extractor and heat, then try just blowing it out with a torch. Again the bolt will melt before the housing gets very hot.

 

[Jim.ME]

If you can't get the old bolts extracted, whether by backing them out using some method, or drilling them out, you can not use a Helicoil or other insert. They need the hole to be installed in.

 

[Texasmark1]

How do you do that? I've seen this recommended numerous times on here and I would like to understand how you get the sacrificial welding element up
against the bolt proper, with the bolt broken off flush with the surface, and get it heated to melting temperature with it frozen in a (usually) large casting
that acts ad a perfect heat sink?

 

[Tim PloughNman Daley RIP]

The 8N-802 drawbar CLEVIS bracket used 4 STUDS originally, then late 8N switched to two different size bolt lengths. Thread size is 5/8-11 into diffy/center case. Both studs and bolts were Grade 8 equivalent. Bolts use 1-3/8" and 1-3/4" lengths. Housing case holes aren't blind (I don't believe) so not going to bottom out. You are NOT going to drill the broken ends out with a hand drill, trust me. Have you tried an Easy-Out? If that doesn't work, you will need to flip the tractor over, or, remove the rear end center hsg and take to a machine shop where they can drill out the broken studs/bolts correctly. If you don't get the broken pieces centered just right (a carbide drill works miracles) it will want walk and encroach the ID of the thread and end up boogered. Drilling by hand, has a few drawbacks. There aren't enough Ponies, 1/3 HP at most, battery units even less, to work correctly, and 2nd, using a HSS drill will guarantee walking and/or breaking. A carbide drill needs to be a solid setup, both tool and workpiece; neither accomplished with a hand drill, in order to function right. So, if an Easy-Out won't work, you will have to resort to Plan B and decide how bad do you want your swing drawbar.


Tim Daley(MI)

 

[showcrop]

(quoted from post at 05:22:28 01/31/21) How do you do that? I've seen this recommended numerous times on here and I would like to understand how you get the sacrificial welding element up
against the bolt proper, with the bolt broken off flush with the surface, and get it heated to melting temperature with it frozen in a (usually) large casting
that acts ad a perfect heat sink?

Mark, it is not real easy to keep your arc on the bolt, you need to be really steady. The main thing is though that the casting that the bolt is in is not the heat sink that you may think it is. You can demonstrate this to yourself using your torch and heat a part that is tightly attached to another. You can get the one part cherry red and blow it away with no tendency of the other to get really red.

 

[pomester]

Interesting, I've not seen this on a Ford. Often the bracket that bolts around the PTO is buggered and casting holes broken but this bracket is robust, I wonder how it got in such a condition.

That said, I have done this on two Fergusons, where the entire drawbar bracket assembly hangs off of those 4 bolts. The only success I've had is to use a cutting torch. I try to punch a hole right up the center so I can use an extractor of some sort. Sometimes the heat along with the metal removal lets the bolt fragment turn out. One tractor all I could do is remove enough of the original bolt to tap out the threads, on a couple of holes there was enough damage to the original threads I tapped and used helicoils. If you do that, note that there is enough depth that you can use two coils, which gains strength. The helicoil holes is where I learned that 11/16" bolts are obsolete and unavailable. I've made a note on that box of taps...

I think you will find these holes blind, at least they are on a Ferguson and it seems like I've observed the casting bumps on the Ford inside of the differential when changing out PTO shafts.

This in a tough job to do in place. Drill lubricant, drill shavings, molten metal, and other debris all falling down putting eyes and other body parts in danger. Be extremely cautious.

Other than that, take it apart and take it to a machine shop where they can work on it right side up with robust tools.

Good luck
David

 

[graham_in_NJ]

I've had luck just welding enough metal onto the remains of the bolt to get a vise grip on. The heat from the weld should help. In your situation, it looks like welding a nut on would be challenging.

 

[Texasmark1]

On heating/cutting, now that you mention it, I have observed that with bolts in castings I have had a torch on for some reason or another....forget.

 

[Neil.640.105091]

Thanks for all the tips and tricks and responses. I think my plan of actions will be to first heat and soak them with penetrant for a couple days. Then I'll start with the easiest attempt of trying to turn them with a cold chisel. If that doesn't work I'll try to TIG weld a nut on and see if that will spin them out. Then I'll step up to attempt to drill (left hand drill bit) and/or extract them. I have access to a Mag drill if I can get it to stick on. The helicoil will be an option if the Mag drill works. I don't have access to a torch to attempt to blow it out. Honestly that option kind of worries me for damaging the casting.
If none of that works, then the draw bar kit will more than likely be going on a shelf for a while. A couple reasons, first the rear section is not the correct rear for the tractor. It appears to be a N series rear. so if I have to break it apart, I'll just find the correct rear section and swap it out. The shells go for around $300 in my neck of the woods. Second, I'm in the process of prepping our new land to build our house on. So I need the tractor in operation. I don't really want to go tearing it apart until I'm ready to restore it.

I will keep everyone posted on how the progress goes. Whether its a success or a complete fail.

 

[showcrop]

Neil, since time is of the essence, if you were to share where you are someone here may refer you to a crackerjack shop in the next town where they have a lift or gantry that would enable them to tip it up on its side and git'r done in a couple hours. I have a friend that would have no problem with that but most likely you are far from him.

 

[Neil.640.105091]

Thanks showcrop.
I'm located in the Springfield Missouri area.