Replacing the internal grip material in a 100-400 mk1 L lens?

[jollyre4]

So we've got an older 100-400 L ultrasonic canon lens, (the one that slides in and out to zoom, not twist to zoom) and the material that grips to add friction is wearing out, even fully tightened down. Anyone ever replace this? Is it even possible?

[ebiggs1]

"Is it even possible?"

Not for the layman but I am sure a reputable shop can. Try Phototronic.biz in Topeka, KS.