(a)

1. (1) The chassis frame shall support the rear body cross member.
2. (2) The bus body shall be attached to the chassis frame at each main floor sill, except where chassis components interfere, in such a manner as to prevent shifting or separation of the body from the chassis under severe operating conditions.

(b) Insulating material shall be:

1. (1) Placed at all contact points between the body and chassis frame on all type buses; and
2. (2) So attached to the chassis frame or body that it will not move under severe operating conditions.