dial string slippage?

[dsk]

I replaced the dial string on a Zenith radio. It is nice and taught, but it still slips on the bushing attached to the tuning shaft. Everything moves fine if I turn the wheel manually (the big one the string goes around with the springs inside), but the bushing on the shaft just is not grabbing the string. It does require some effort to turn the wheel. Is it a situation where I need to lubricate something or increase the friction on the string? I tried some bow rosin on the string to no avail. What should I do?