Technical Service Bulletin Cylinder Head Stud Exhaust Sides

Subject: Cylinder Head Studs Exhaust Side    Models:911/930 1977 ->

Bulletin Number: 77-04

When cylinder head is removed during major engine repairs, include the following operation:

  • Remove cylinder head mounting studs on exhaust side of crankcase (6 on each side).
  • Install “Dilavar” studs (shiny), Part Number

930 101 170 02


Always replace studs on both banks of cylinders.

  • Use Loctite Number 270 on end of stud that goes into crankcase
  • Screw stud into crankcase until protruding length is 135mm (5 – 5/16 in.) (see fig below).


Part numbers for identification only. Always consult Parts Department for correct numbers.

home page:

Want More?

Get the coolest tips and tricks today

Subscribe to our email list and get regular notifications of new videos and blog articles on how to repair your own car.