cheap tech trick, w113 only gas pedal
 

My 64 sl had a slight notchiness somewhere in the linkage, no big deal but at about 1/4 throttle I have had (for years, but getting slightly worse) a slight resistance that I could never trace. After cleaning and lubricating everything else, I finally ended up at the gas pedal. Eureka! There is a thin flat (I would say teflon, but that wasn't even invented then, I think) insert in the upper receiver at the top of the gas pedal. I took it out, cleaned it, and found a wear notch. Just turned it over, reinstalled, and voila...good for another 39 years I think. Sometimes its the simple things, but happy I am.