[Gelbster]

Here is a different approach to consider.
One early sign of IMSB failure is oil inside the 'sealed' IMSB. By the time there is metal in the filter it may be way too late .
So remove the cover, pry off the bearing seal and inspect for oil ? Test bearing for wobble.
Many of the new kits have this front seal removed to improve the lubrication of the bearing so this does no harm.
If you find no grease and just oil in the bearing, ask for more opinions?
Remember the replacement kits also upgrade the weak grooved bolt.