hondarider6

i have a 2000 lifted f150, and when ti shakes when slowing down around 45-40. Is it because of the bigger tires? or is it the brakes?

dcfluid

Could be several things but try the most likely first.
Are your wheel nuts tight?
Get your front end into an alignment shop to check for alignment and worn joints. A control arm is one likely cause of front end shake while decelerating. Have someone watch you slow down and watch from the roadside as you induce the shake, if it is bad you can see the front tires move in and out, shaking the truck.
Do this after you make sure your lug nuts are tight.
If it's brakes you will feel a pulsing thru your pedal and the truck feeling like it has a slip then grab sensation as the rotor turns thru the pads. This would imply warped or glazed rotors. You would feel the pulsing but it wouldn't actually feel like a wheel falling off or the front end wore out. Braking can induce a front end problem to start shaking, but if you have the same problem just by letting off the gas then brakes are ruled out.