Removing Rusted Control Spring Adjusting Yoke and Lift Arms

I am working on a TO-30. It seems every part is either worn pretty well or rusted to the point of being nearly impossible to remove. The Control Spring Adjusting Yoke is supposed to be adjustable but this one has the yoke rusted to the Lift Spring Control Plunger. Also, the Lift Arms are solidly rusted to the Hydraulic Lift Shaft. I have removed the Hydraulic Lift Cover, and the cotter pin out of the pin that attaches the plunger to the Spring Control Fork. Can you tell me how to remove the Lift Arms, or the Control Spring Adjusting Yoke off without destroying anything? May 20, 2015.

This is going to call for some rather drastic measures, at least they may seem to be drastic until you take the time to analyze the situation.

First, you have to get the fork assembly free from link. Use a die grinder or angle-head grinder with a cut-off wheel to cut the clevis pin on both sides of the plunger. The pin is relatively inexpensive and easy to replace. This should free up the fork assembly.

Remove the 3 bolts holding the cap/cover on the front of the draft control spring and you should be able to withdraw the entire spring and plunger assembly. Once you have it free you should be able to use penetrating oil and heat to free the plunger from the yoke. If that doesn’t work you will have to use a cut-off wheel or hack saw to cut the plunger.

Salvage what parts you can, particularly the spring, and buy a new or replacement plunger and yoke assembly. Ford parts and Ferguson parts are interchangeable when used as complete assemblies. The threads do not always match; the plunger and yoke must be matched. The thread is a special thread, similar but not the same as 5/8″ NF. After-market parts are available.

When you reassemble the unit, use anti-seize compound on the threads. After the repairs are made you should periodically unscrew the plunger from the yoke and coat the threads with anti-seize compound. You can also use grease but anti-seize compound lasts longer.

To remove the lift arms, turn the cover on its side and begin making applications of Liquid Wrench or your favorite penetrating oil. Heat the lift arm around the shaft and use a hammer, preferably a brass or dead blow hammer, to drive the arms off the shaft. You can also use a heavy brass block on the ends of the shaft. You will have to drive the arms off and then on, a little at a time, make additional applications of penetrating oil and heat to free the arms.

Be careful not to damage the lift cover. If the lift arms will not budge you will have to use a die grinder to split the lift arm where it wraps around the lift shaft. Used left arms are readily available as are lift shafts. If you can get one arm off, wire brush and clean the splines and remove the shaft from the ram arm and the top cover housing. You can then put the remaining arm and shaft in a hydraulic press to remove the remaining arm. The bottom line is you may have to sacrifice some parts to disassemble the yoke and plunger, and left arms and shaft.

Used parts are plentiful so this should be no problem. If you must replace either of the lift arms, look for used Ferguson parts as they are a bit beefier than the Ford parts. Ford parts will work however.