TOPIC: NHT oil pump mounting studs

This issue came up on NOC.
NOC forum is quite poor IMO, so I offered this bit of info:

I responded to oil pump mounting problems...

1. The alloy case getting pulled up and distorting the 26cei mounting?

2. Daft owners kept stripping out the alloy threads? installing or cross threading wrong thread?

3. Up to 20M3S case threads are 26 CEI... helicoil only on damage repair

200000 series changed to 5/16-18 UNC stud X 5-16-24 UNF nuts Cases all helicoiled

300000 series cases continue 5/16-18 UNC stud X 5-16-24 UNF nuts Cases all helicoiled

325000+ cases helicoiled - 5/16 UNC bolt/washer