Center Link Flip – Datsun 620

In order to accommodate a larger oil pan that is common on most engine swaps, the center link must be flipped. The information below will outline the process. However, you should review your local laws before making any changes to the vehicle. This guide is intended for informational purposes only, do at your own liability.

What you will need:

• 11/16th drill bit
• TeraFlex Tapered Insert Sleeves 990175
• Dremel tool with metal cutoff disk

The biggest obstacle for completing this flip is getting the correct sized taper for the 620 center link tie rods ends. All of the available tapered inserts I have found are for jeeps. The smallest being the stock TJ insert. 

TJ Tie Rod End – bottom of stud (larger end of taper) = .62″

620 Tie Rod End – bottom of stud (larger end of taper) = .60″

When test fitted this .02″ differences is quite large and causes the tie rod to go too far into the insert to the point it squishes the boot and allows for almost no movement in the tie rod.

This is why the Teraflex insert must be used. By using a dremel we can modify them to fit the stock 620 tie rods. However before we get to this the idler arm and pitman arm must be prepared first.

Ideally the idler arm and pitman arm should be removed and drilled with a 11/16th bit on a drill press to ensure straight even holes. However, there are stories of people braking pullers trying to remove pitman arms, so if your confident in your skills you may choose to drill them while attached to the frame. This is a good time to do some research on drill bit speed and pressure as when you get it right holes are pretty easy to drill, if you get the speed and pressure wrong you’ll burn out your bit or get and uneven hole. The arms are made of very strong steel, you may have to sharpen your bit before completing the first hole. Drill bit coolant/lubracant can also help.  Double check before drilling holes that you are drilling the correct ones and not the ones the outer tie rods connect to. Once these holes are drilled we can work on modifying the teraflex inserts to fit our stock 620 tie rods. 

To modify the tapered inserts use a dremel to slowly remove material from the insert where the gap is to allow expansion. Then pinch it together with a vise, carefully rotating it while clamping to ensure it stays round. Keep repeating this step until the insert fits in the 11/16th hole drilled earlier. Do this for both sides. The center link is now ready to be flipped. When installing the tapered insert may stick out slightly above the pitman or idler arm, it may be necessary to file or sand it flush before securing the tie rods.

Unmodified Insert Fitment

Protruding Insert