My 63 D model 172’s AI bearings are making noise and it’s starting to go haywire. A friend of mine just upgraded to a G5 but he’s in a 172M. He’s offered to give me his AI to get me going again. Are these vacuum fittings standard on these Vacuum gauges? Thanks.

Airfoil92 wrote:My 63 D model 172’s AI bearings are making noise and it’s starting to go haywire. A friend of mine just upgraded to a G5 but he’s in a 172M. He’s offered to give me his AI to get me going again. Are these vacuum fittings standard on these Vacuum gauges? Thanks.

The fittings on the back of the gauges are all standard. What connects to them can be anyone's guess after all these years. But the one from the M should definitely work fine in your 63.

Thanks for the input. That doesn’t look like any fun for a mechanic to replace. Looks nearly impossible to reach and replace!

Airfoil92 wrote:Thanks for the input. That doesn’t look like any fun for a mechanic to replace. Looks nearly impossible to reach and replace!

That's why you do it yourself. Much cheaper and your mechanic will appreciate it. lol

The bearings are generally cheap and easy to replace as well on many models if you are careful and scrupulously clean.It is best to replace them soon after you start hearing noise or the erection vanes start to wear.

The old original AI looks like the fittings are on the back but more on the side. The new one, has everything on the back. Guess we will know after removing it.