Photo 2/6 | 01 Top Tech Regearing For Bigger Tires F350 | Gearing down one ratio for every 2 inches of tire height is a general rule of thumb to maintain a truck’s acceleration and towing performance. For example, switching from 33-inch tires to 37s requires changing a 3.55 gear ratio to 4.10. Online calculators provide exact tire-size-to-axle-ratio numbers.
Photo 3/6 | Top Tech Regearing For Bigger Tires Ring Gear Bench
Photo 4/6 | 05 Top Tech Sputtering Ram Cummins Vp44 | The Cummins VP44 injection pump is very reliable as long as it’s given a 12- to 16-psi supply of clean fuel. Cummins injection experts warn that fuel pressures of less than 8 psi are a fast track to premature pump failure.
Photo 5/6 | 03 Top Tech Dis Jointed Driveshaft Dmax | Thrown driveshafts on lifted trucks are usually the result of improper geometry, coupled with not stepping up to a larger-diameter, correct-length shaft. The driveshaft shown here is too short, as evidenced by the wear pattern (arrows) of the output-shaft seal on the slip yoke. Lift blocks and excessive axlewrap can also contribute to dropping a driveshaft.
Photo 6/6 | 04 Top Tech Ford 6 0 Shop Mechanic | Hard-starting Ford 6.0L Ford Power Stroke engines in trucks that have been parked with the nose higher than the tailgate usually draw the attention of diesel technicians to the high-pressure oil pump located at the back of the valley. Leaking seals or a bad injector-pressure regulator are the usual suspects that cause the problem.