How to Free a Stuck Draft Control Spring

Can you tell me a good approach to breaking free a stuck draft control spring? June 1, 2016.

The operator’s manual directs owners to disconnect the top link rocker, unscrew the turnbuckle, and grease the threads every six months. Today anti-seize compound is far superior to grease. Sadly, this simple maintenance procedure was, and is often ignored.

Most of the Ferguson system tractors today have not had their turnbuckles unscrewed in what could be up to more than 75 years. That means the threads on your turnbuckle and plunger are likely frozen with rust.

As rugged as the top link rocker and control spring appear, the components at the other end of the threaded control plunger are fragile and easily damaged. Disconnecting and removing the top link rocker and applying force to the turnbuckle is likely to bend or break the upper and lower forks and likely the control valve.

The best solution is to remove the top cover after disconnecting the top link rocker,and the control valve at the bottom of the lower fork assembly. Once the top cover is removed you will be able to remove the clevis pin that attaches the plunger to the upper fork, remove the three bolts securing the lift spring seat support, support plate, plunger, and control spring assembly. With the control spring assembly removed you can begin applying penetrating oil and hopefully be able to unscrew the turnbuckle from the plunger. Be patient, you should be prepared to apply penetrating oil for several days.

With the assembly removed you should also be able to carefully apply heat to break the threads free. You may not be able to unscrew the threads and if not your only option is to cut the plunger with a hacksaw. You will then have to purchase a new turnbuckle and plunger.

Different threads have been used on the turnbuckle and plunger assemblies over the years so be sure you purchase a matched assembly from the same source. After-market parts are available and the same parts are used on the Ford Ferguson 9N, 2N, TE/TEA-20 and TO-30. Many of these after-market parts will also fit the Ford 8N.

Again, as long as the turnbuckle and plunger are from the same source and a matched set, they will work. You should also replace the felt dust seal on the plunger. It is also possible the lift spring seat support is badly rusted and will have to be replaced. Again, these are available from after-market sources. Check the spacer and seat support and if badly rusted they may also have to be replaced.

The Ferguson version is two pieces while the Ford version is a single piece. The two piece assembly can be replaced with the single piece version. After rebuilding the control spring assembly, reassemble the top cover and reinstall. Make sure you use a new gasket under the top cover. Once assembly is completed you can adjust the control spring and quadrant as described in the operator’s and shop manuals.