MG Car Repair: mgb suspension knock, disc brake pads, thrust washers

Question
when i brake hard front dips i get a knock on front left can you help thank you.

Answer
Hi Kenneth.  You probably have some wear in the nearside front suspension.  

There are several possibilities, but most likely the thrust washers at the bottom of the kingpin are worn, or the base of the kingpin itself.  This often happens, especially if the kingpins are not greased regularly.  

If you check the gap with a feeler gauge, it should not exceed .008 inches (8 thou).  Ideally, it should be between 2 and 5 thou.  Sometimes you can get away with turning the thrust washers around and carefully grinding a small amount off the end of the spacer tube, so as to reduce the free play to within these limits.  Do not over-do it, there must be a minimum of 2 thou clearance or it will lock solid.  

Other possibilities are a worn kingpin bush, excess fore-and-aft movement of the shock absorber arms, or excess movement of the disc brake pads.