Steering Systems 1 Steering Gears 2 types of

Steering Systems 1

Steering Gears • 2 types of steering gears Ø steering box Ø rack & pinion 2

Recirculating Ball Steering Box • less precise steering “feel” Ø advantages Ø disadvantages • offers good mechanical advantage • bulky/heavy 3

Steering Box Linkage • parallelogram linkage Ø transmits steering box movement to the wheels 4

Rack & Pinion • • less mechanical advantage (compared to steering box) lighter – fewer parts compact more direct feedback & steering “feel” Ø advantages Ø disadvantages 5

Fun Fact… • early (1913) rack and pinion… 6

Rack & Pinion • tie rod ends transmit motion from the rack to the steering knuckle • they also allow for up & down movement thru bumps & pot holes & turns 7

Power Steering • power assist steering helps the driver turn the steering gear with reduced effort • on almost all cars, a belt driven hydraulic pump is used • this pump generates hydraulic oil pressure which is used to help move the steering gear 8

Power Steering – Rack & Pinion • hydraulic pressure is supplied by the engine driven oil pump • rotary spool valve directs hydraulic pressure to the rack piston based on driver input 9

Power Steering Box • worm nut doubles as the hydraulic piston 10

Steering System Service 11

Re/Re Power Steering Pump Pulley • use proper puller & installer Ø used when replacing or repairing the power steering pump 12

Steering Column • column u-joints connect steering column to steering gear • u-joints should be checked for looseness • they can also bind which leads to stiff steering 13

Power Steering Fluid Leaks • check the 2 lines that connect pump to steering gear Ø hose clamp = return (low pressure line) Ø threaded hose end = high pressure line • power steering pump Ø can be disassembled & resealed Ø or install a rebuilt pump $50 to $100 15

Power Steering Fluid Leaks § steering gear can be leaking • steering box can leak… Ø pitman shaft seal Ø cover seal Ø adjuster plug seal • steering rack can leak… Ø fluid lines Ø pinion seal Ø piston seals 16

Rack Bushings • rack bushings isolate the passenger compartment from road noise & vibration Ø check these 2 bushings for deterioration 17

“Rag Joint” • vehicles with steering boxes (and some rack & pinion units) use a “ rag joint” to isolate the steering wheel from road noise & vibration Ø these should be checked for deterioration 18

Checking Steering Linkage Wear • rack & pinion Ø check inner & outer tie rod ends Ø grab the front & back side of the tire Ø rock it back & forth Ø watch for slop in the tie rod ends 19

Checking Steering Linkage Wear § parallelogram steering linkage § move front tires in & out • check for looseness in… Ø pitman arm Ø idler arm Ø center link Ø inner & outer tie rod ends 20

Checking Steering Linkage Wear § alternately, you can check the linkage this way… • leave the vehicle on the ground (or drive-on hoist) • have an assistant move steering wheel back & forth thru the free play • look at the linkage for slop, wear & movement 21

Disconnecting Tie Rod Ends • leave the nut on, but loosened – this will protect the threads from the hammer • tap the knuckle with a ball peen hammer • a “pickle fork” can be used if the tie rod end is being replaced 22

Replacing Pitman Arms • once the nut holding the pitman arm to the pitman shaft is removed, a puller must be used to remove the arm from the steering box 23

Removing Steering Wheels • after retaining nut is removed a puller must be used 24

Steering Wheel Lock Plate Removal 25

Power Steering Fluid Changes? 26

Recent Advances • Electronic Power Steering 27