Replacing 2CV axle bolts

The final item I had left on my to-do list from the re-chassis was to replace the axle bolts. Whilst doing the re-chassis we re-used the old bolts but they were showing signs of necking (although TomB engineering assessed they were within tolerance).

Old 2CV axle bolt showing necking

The bolts are held in place with lock washers which are bent over at the ends to prevent them working loose so the first step is to bend these back to get access to the bolt heads. As the bolts are what’s holding the axle to the chassis removing both at once could allow the axle to move relative to the chassis which would mean it’s no longer possible to get the thread to engage in the axle mount and, given the forces from the weight of the car and the spring tension in the suspension, it is very difficult to re-align things if they move (thus spake the voice of experience).

To avoid this it is best to replace them one at a time. To do this first loosen off both bolts just enough to free the lock washer, then take one bolt out, rotate the old lock washer out of the way then insert one new bolt and the lock washer ensuring the threads are fully engaged in the axle.

2CV axle bolts and lock washers mid-replacement

Now take out the remaining old bolt and lock washer before fitting the remaining new bolt through the lock washer.

2CV axle bolts

The bolts are then tightened up to 50 N m and, using a persuadatron and a cold chisel, the lock washers are bent around them to… well… lock them in.

2CV axle bolt with bent lock washer

For comparison, the new high tensile axle bolts and lock washers with the original bolts and washers that were used during the re-chassis.

Old and new 2CV axle bolts and lock washers

Of course, someone wasn’t too happy about the disturbance to his afternoon snooze.

Cat looking suspicious on top of a 2CV