Offset feeler gauges are recommended for this, through the Amazon Affiliate Link: https://www.amazon.com/gp/product/B00...

Diesel valve train adjustments seem like voodoo to many people, but it isn't too complicated. This video will go over the fundamentals of performing a Cat overhead adjustment for the intake and exhaust valves. Did this video help you save time or money? If so, consider sending support on Paypal, for the username [email protected] and thank you very much for watching.