Fitting the A Frame requires it to be central to the chassis with equal distance between end of the DeDion tube and the chassis frame on both left and right sides. Washers are used to pack the gap between the chassis and A Frame to get the centring correct.
The A Frame was introduced to the chassis and dry fitted with the single imperial bolt into the DeDion tube and the two metric bolts into the chassis. The right hand chassis bolt slipped in without a problem - the left hand one felt tight, but loosened up after a couple of dry fits. At this stage, measurements were also taken between the chassis and the end of the DeDion - they were roughly equal. Measuring stacks of washers showed that 3 would be needed on each side. With that confidence, the A Frame to DeDion bolt, two nylon washers (to prevent squeaking) and the nyloc nut were fitted (with CopperSlip).
Fitting and tightening the A Frame to the DeDion tube
The left hand chassis bolt was fitted first (being the one that was slightly binding). The same method was used as before - CopperSlip on the bolt, slide it through the chassis bush until the tip became visible on the other side, then introduce one washer at a time using a flat blade screwdriver to manoeuvre the washer. The same approach was used on the right hand side, although the last washer was of course a tight fit and took a good push with the screwdriver tip to get it past the lip of the A Frame bush.
Once the bolts were installed, measurements of the DeDion to chassis tube were retaken to verify the A Frame was correctly centred. They were equal to within 1mm.
Checking the centring
Now that the rear suspension components were fitted, the car jack was positioned under the DeDion (at the connection point with the A Frame) and the car was lifted. With the suspension components now supporting the weight of the car, all of them were torqued to the prescribed amounts.