Sony C20 Betamax problem

[tiv48]

i belive its a fault with the pendulum although never heard it called that before they or we used to call them idler drives , they tend to get contaminated with tape oxide or the friction pad just wares out, i have soaked them in ipa but only a tempery repair. on no account use oil or wd40 on it , this fault is common to a lot video recorders not just sony and was the most common spare part kept for all makes, on earlier models that used rubber tyre we used to just change the tyre
rob t