Just finished the rear axle overhaul at 140,000 miles. It's the first time the car has needed some work here and has previously only had alignment at around 90k miles.

The reason for this work was unusual tyre wear: the centre area of the Michelin Diamaris rears had uneven wear around the circumference, and with the wear indicators levelling it was time for a change. There was no edge wear of significance. The rears have made 18k, the fronts are better at 26k but I'll replace all four (will try a different brand this time).

With the pressure off the air suspension, a helper showed that the balljoints and wishbone outer links were worn - maybe 1/4 inch movement at the balljoint and slightly less at the wishbone.

The front upper arms had deteriorating rubber on the joint, so these got replaced as a precaution. The integral links were very good - but I replaced them anyway - as were the lower arm inner bushes. Both upper arm bushes were good. The drop links are also OK but I'll replace them along with the sway/anti-roll bar mounting bushes once finances recover.

The balljoint extraction needed a lot of cleaning to present a flat surface for the tool. I bought an Asta tool from eBay for ~£36/US$47 - this worked really well. One wishbone balljoint couldn't be separated and I had to split the 22mm nut. One upper arm balljoint did the same - I broke into the joint and ground a pair of flat surfaces so I could hold it and free the retaining nut.

Post alignment I'll treat the fresh metal surfaces to try to make this job easier next time around.

Replacement parts: Lemfoerder arms, TRW balljoints, BMW holders on the wishbones. Approx £270/US$470 including the balljoint tool.

I'm impressed that these parts have generally all worn so well over this mileage. I'm sure my predecessor E39 didn't have this longevity at the rear axle.