I recently started using my C-172 for instrument training.  Until now I used the VOR indicators only infrequently for cross country flights, and the indicators seemed to work well enough.  Now that I am using them for approaches, it seems when I am a few thousand feet or lower, and within a few miles of the VOR, I get the needle swinging 10 degrees side to side, and inaccurate indications of the radial.

On the Localizer/ILS, it's a different story.  The needle indication is solid all the way to the runway.  This makes me think it may be something other than the equipment.  I would be interested in hearing from anyone who may have had the same problem, and what you did to correct the problem since the indicators are worthless for doing any kind of VOR approaches.

The equipment I have are two TKM MX170B Nav/Coms driving a King KI-214 indicator w/GS receiver and a King KI-208 indicator.  The indicators are old, but how old I don't know because there is no logbook entry as to when they were installed.  The TKM radios are 5 years old, and are slide-in replacements for the King KX-170B radios that were probably installed with the indicators.

I would appreciate any and all advice.

Thanks

Jon Plaxton