Rack And Pinion Steering Systems

By Author: jardinvalla
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Sometimes, you will be asked what the steering ratio is when ordering a rack and pinion, or more often, what is the lock to lock. Steering ratio is the relationship of how many

degrees the wheels turn in relationship to how far the steering wheel turns. For example, if the steering wheel is turned one complete rotation (360 degrees) and that makes the

wheels turn 30 degrees, the ratio is 360/30 or 12:1.

Higher ratios make it easier to turn the wheel, as you need to turn the steering wheel more to move the wheels. Lower ratios are normally found on high performance vehicles.

Lock to lock refers to how many turns of the steering wheel it takes to go from full left to full right. For example, if the wheels are turned fully to the left, you count how many

turns of the steering wheel it takes to have the wheels turned fully right. If you turned the steering wheel 3 1/2 times, you would say you have 3.5 lock to lock.

Variable ratio steering on rack and pinion steering is accomplished by having more teeth in the center of the rack and less on the ends. This makes it easier to drive, as ...
... when you

are moving straight at highway speeds, you will not over correct as you try to keep the vehicle moving straight. More teeth on the rack means you need to move the steering wheel

more to turn. The smaller amount of teeth on the ends make the wheels move more when fully turned, making it easier to perform maneuvers such as parking.

Fixing Rack and Pinion is an Easy Task

A steering rack and pinion may need to be replaced for several reasons. You may notice that power steering fluid needs to be added, which is a sign the seals may be leaking. You

may not see this right away as there are boots at the ends of the rack and the fluid may be going there. Another problem is the bearing where the steering shaft attaches often goes

badly. This would cause a noise as well as a scraping sensation when you turn. Racks often make bumping or thumping noises when the internal parts are worn, or the mounts

have simply come loose. The most common signs the rack has gone bad are the steering will be stiff when cold, it will be harder to steer than normal and the wheel will not

return to center by itself. If any of the above conditions exist, the rack should be replaced. From my own experience, rebuilding the rack with simple seals and bearings is usually

just a short term fix and the rack and pinion will soon need to be replaced. This is probably due to normal wear and the buildup of worn parts that cannot be cleaned without

taking the whole unit apart and rebuilt. There are approximately 45 individual components in the average power steering rack and pinion. Valves, seals, the rack tube housing,

the pinion housing, lines, bellows which would all need to be cleaned to properly rebuild the unit.

A steering rack and pinion system is a much simpler system in many ways. When turning the wheel,the steering shaft turns the pinion and moves the rack back and forth. This in turn moves the tie rods and then the wheels turn.There are inner and outer tie rods on all vehicles with Rack and Pinion steering. For more information visit our site.