Originally Posted by Gregory891

Everything you wanted to know for the E53 rear shocks and using real (yellow) Bilstein B6 shocks.

Officially the Bilstein catalog listed a B6 (single tube, high pressure) rear shock for the E53 except self leveling suspension. It clearly is in error, as the rear air spring system simply replaces the coil spring, the rear shock is a separate unit in both (identical) cases. The part number for the original low pressure (Bilstein B4) shock is different for a stock, sport and rear air spring suspension, it's just a difference in valving. The front self leveling system which is an entirely complete system (air spring and shock), so you either keep this system or entirely convert to springs and conventional shocks.

Again, for the rear, there is no difference. Bilstein is in error. I found this with my former E34 touring and had them correct this error back in 2007 or 2008. For the X5, I researched this long and hard and wrote an email to Krupp-Bilstein with the findings, part numbers, comptitive shock listings, etc.. After no reply in a month, a paper letter. After another month of no reply, I tried via Krupp-Bilstein in the US and promptly got a reply. Helpful assistance, they confered with Germany and confirmed that yes their catalog was in error and that they would correct this. They should have corrected their catalog by now (my emails were Sep/Oct 2012) but in the event it's still in process, read on.

Bottom line. ALL E53 can take the BE5-A744-H0 (B6) rear shock. Not because I say so and Bilstein confirmed I was correct, I've done it on my car.

I just installed a pair on my 2002 X5 3.0d. It has rear only self leveling suspension. Start to finish it took an hour. I didn't jack up the car, there is enough clearance to do from underneath. Upper access isn't fun, but after you remove some plastic covers, you can do the job. You can save time and upbolt the shock rod at the top and leave the upper mount in place.

My old shocks (original rears, Bilstein B4 twin tube low gas pressure) did 245.000 km of service, not blown and they still had pressure.

CONCLUSION: X5 rides better. Front to back pitch essentially gone. You can sense it's firmer in the back but not at all jarring. Also nicer in on & off ramps, sharp turns. Less tramming effect as well. Overall a bit firmer than before, but again as the old shocks are original to the car with 245.000 km it's not a fully objective new vs old comparison. I run the factory 17" wheels / tires, which would be more compliant than 18" or 19" tires. Roads in my part of the world (Switzerland) are in fairly good shape, not racing track smooth but few pot holes.

Definitely pleased with the results, I want better and a bit firmer but am not trying to make an M car. I had also replaced by final stage resistor at the same time, my heater fan had entirely stopped working with no funny signals up to that point. You CAN replace in 30 minutes and you do NOT need to remove the glovebox (LHD car).