The drag link caps contain a strong spring which holds the hemispherical cups at each end tight on to a ball. The balls respectively form part of the steering drop arm and the steering arm on the off-side hub. These two assemblies should be checked for wear from time to time. If you have never made these checks, perhaps it’s time to do so. At a later date there will be an article on what to do to reduce excess movement in this part of the steering.
Assembly at drop arm end
Meanwhile, if you want to make a check, you may find the load on the spring makes it hard to remove the through bolt which holds it all together, and indeed even more difficult to get it back in again. Having a compression tool as shown in the picture enables the spring load to be taken up and the bolt hole aligned for free removal and replacement of the bolt.
It can be seen that there are four main components to the tool: - two “strong-back” plates and a couple of tie rods.
Assembled gadget
The plate thickness should be ⅜" or 10mm thick and measure 1½" (40) by 2½" (65). The tie rods should be ¼" or 6mm diameter and 25" (650) long. One plate should have clearance holes for the rods on 1¾" (45) centres and the other needs ¼" or 6mm tapped holes on the same centres. Ideally, to prevent the plates from skidding around, as you tighten the nuts to load the tie rods, the plates should be “scalloped out” on their centres where they mate with the end caps – as if they had been introduced to a 1" drill bit!! You may achieve the same effect with a rotary file or maybe braze a suitable diameter short ring on to the plate.
The rods obviously need to be threaded at each end; one just matching the plate thickness and the other having a generous inch of thread. Secure the rods firmly in the plate. Use Loktite Studlock, braze, solder or peen over – take your choice, you want them to stay in !
Finally, make sure that only high tensile bolts are employed on this critical part of the steering. Any sign of fretting or damage to threads demands replacement. Split pins and castellated nuts should always be used. If fitting a new bolt prepare the hole for the split pin. Make a trial assembly with a couple of washers added, note the distance the nut runs up the bolt and take apart. With the nut returned to the previous position drill through the bolt using the nut castellation as a guide. Refit and pull up tight - adding or removing washers depending on how accurately you positioned the split pin hole.