I started by checking I have the correct Anti Roll Bar (ARB) bushes for the ARB that’s being installed. The colour of the spot on the ARB should match the bush colour. The front ARB bushes are packed together with the ARB balls, rubber boots and mounts. Be careful not to get confused with the orange bushes used for the rear ARB (fitted to R models).  

Correct bush for the ARB

I put the ARB ball onto a spare bolt so it’s easier to test the fit with the front upper wishbone – as expected it didn’t. Like my previous 360R build, I needed to remove the burs from the ARB balls and clean the powder coat from the upper wishbone ARB ball cup. With the ball on the bolt, a bit 600 grit wet-and-dry sand paper removed the minor burrs. 

Next, I protected the the wishbone, because I used my Dremel with a sanding band to clean the powder coat from the ARB ball cup. I did this little by little until the ball just fitted into the wishbone. Don’t go too far and make the ball loose in the cup, it wants to be tight.

Assembly of the ARB starts with putting the bushes into the bush mounts. Use a rubber lubricant: An old can of Halford (https://www.halfords.com) Rubber Lubricant spray worked perfectly for me. With the bush installed in the bush mount, slide the bush (and mount) onto the ARB bar. Again, lots of rubber lubricant makes this easier. Next install the ARB ball boot onto the ARB, and finally screw the ARB balls onto the ARB. The balls only need to be hand-tight (a rubber glove helps to get more grip) but use a fair amount of thread loc (I use Loctite 243 to give the thread a good coating). Apply a small amount of grease into each cup before I install the ball, too much and the ball won’ seat properly. 

Also, before I fitted the ARB to the chassis I put the bolts into position with a little copper slip grease, and moved the mounts into the middle of the ARB so they don’t touch the chassis paint work while locating the ARB. 

To fit the ARB, push one ball fully home on one side, then push the second ball in; this does need a little force to flex the ARB into position, but no levers or tools are needed. 

To locate the ARB bush mounts (and prevent paint damage to the chassis) I pulled the ARB forward a little and slid the mounts one at a time into position. Once all the mounting bolts are located, I torqued them to 20Nm as recommended in the new build manual (v1.2 and v2.0).   

Finally, I packed the cup with Castrol multi-purpose grease (if you’re old-school like me, LM Grease), before fitting the rubber boot with a couple of tie wraps. I used a slightly thinner tie wrap to that supplied in the kit to get a better fit with the very small recess in the rubber boot.

Tools Used

  • P600 Wet and dry sand paper
  • Dremel with sanding band
  • 13mm 3/8 socket
  • 3/8 Torque Wrench
  • 3/8 Ratchet
  • Side Cutters

This didn’t exactly go as planned because my front upper wishbone had a manufacturing defect that prevented the RHS rubber boot from being fitted. The weld for the ARB ball cup extended into the recess for the rubber boot. Caterham exchanged the part but fitting it did require taking a few steps backwards in the build process.