My '72 El Camino (Hidden Wipers) has started to make a "clunk" when first turned on, as it starts to move out of the park position. On either speed they are silent while on, and when turned off they park quietly. When on intermittent (aftermarket switch) it parks every time so I get the clunk every time. Being in Seattle area I want to fix before it goes completely. Should I try lubrication, if so, can I get to it thru the cowl grill?