Replacing belt on 400E, a piece of cake.
Got the drive belt from Partshop, installed it this Saturday, it only took my 15 minutes, I didn't remove anything but the old belt, the fan shroud blocked the 19 mm bolt a little bit, but it was very flexible, I was able to loose the bolt easily with my 3/8 torque wrench.
Before that my old belt was very loose, and it showed a lot of cracks on it, I also worried that my tensioner was dead. It turned out that my tensioner was still good, I was able to tighten the belt. Unlike someone said, I feel removing belt and tensioner is a pretty easy DIY job.
My engine now is 10 dB quieter than before, no more squeals from the belt!!
99 BMW 540i 6-speed 110K Km
03 SAAB 9-5 wagon 80K Km
92 400E (Sold) 245K km
Still missing the days with the Benz, it kept me busy.