hi all tried to fit some front seat belts, as i have harnesses at the moment,when i hold the seatbelt upright i can pull it out, but as soon as i tip it at an angle to bolt on it will not pull out at all, i know they are inertia and lock when braking or sudden movement but i can not even get it on. have they had it or can they be adjusted or some thing. advice would be welcome. cheers frankie