I beleive this topic has been discussed although I can not locate the appropriate threads. My case at the oil filter cover (bottom allen head bolt) is now stripped out from the metal particles that fall into the allenhead shoulder bolt threads. Although I clean this out thoroughly with contact cleaner, the threads inside the case are stripped out. What is the fix to this? A helicoil or replace the entire case. The hole from the oil filter cavity seems to have no function other than to drop metal onto the bolt threads. Has anyone plugged this hole? As you remove the allen head bolt the metal particals are ground into the threads of the case. Has anyone else had this issue or know what the fix is other than complete replacement? This is the first time this is happened to me after owning 4 426's. Any help will be appreciated.