Gear airspeed switch adjustment

[JimB]

I have not crawled under my dash yet but it looks like my airspeed switch needs a slight adjustment. The AMM gives a very vague description "5. Adjust switch body until switch closes at an increased pressure of 2.416 to 3.158 inches of water (75+5 MPH), 6. Secure setting with a setscrew." Is the adjustment under the straight slot cap or is it the screw on the other side?

[PT20J]

The small stud/nut just holds the housing that covers the micro switches. The big screw should adjust the spring tension on the static side of the diaphragm. Here are some more pictures and info:

https://www.knr-inc.com/shoptalk-articles/25-shoptalk/93-201901-electric-gear-safety-system

Skip

[JimB]

6 hours ago, PT20J said:

The small stud/nut just holds the housing that covers the micro switches. The big screw should adjust the spring tension on the static side of the diaphragm. Here are some more pictures and info:

https://www.knr-inc.com/shoptalk-articles/25-shoptalk/93-201901-electric-gear-safety-system

Skip

Thanks Skip. I am in the middle of doing my gear checks on my first annual and it seemed to take a little more pressure than I would have thought to get the gear to come up. So I hooked up my pitot/static test set, ran it up and the switch is made right at 75mph so I'm happy. Also went ahead and removed my gear actuator to check the gears even though that part of AD/SB isn't technically due (have pics if anyone wants to see). Just wanted to make sure they have been maintained well over the years and they looked great. Got everything lubed, emergency extension checked, preloads and spent the rest of my evening last night putting the 400 screws back in the belly panels. 

I like those shoptalk articles on that KNR site. Very informative.