I have a problem with the seat not locking into place on the right side slider. The slide opposite the adjustment knob appears to slide regardless if the slider lock knob is activated or not. This results in the right side of the seat not locked into place when driving. Is there a spring mechanism missing from the left slider to the right slider? What could be the problem? - thanks guys.

Theres a tooth that stickes into the rail. When you push the slide handle it disengages the tooth from the rail. Sounds like your tooth is broken off.

Only the side with the mechanical adjuster has a positive lock. The other slide has a long spring to provide resistance.

thanks Mike, I guess that's the way it's supposed to be - seems unusual to have one side of the slide "unlock".