weight of steering when engine off

[roverbarmy]

Originally Posted by macafee2

Reason for my question, I was always taught not to turn the steering wheel when stationary as it puts a lot of strain on the steering components and can damage what is beneath the wheels.
macafee2

Agreed. As an ex HGV man with years of driving with no power steering (big shoulders!) you get into a habit of only steering whilst moving, even rocking back and forth when manoeuvering in tight spaces! It makes me cringe when I see folks spinning the steering whilst stationary.

[macafee2]

Originally Posted by topman

Seems to me if you wanted to know, you'd have to use a push-pull gauge. Attach the gauge to the steering wheel. Move the steering wheel x amount of degrees then do the same with the engine running. That would tell you the difference.

I'm just looking for a rough idea and thought someone may know.
If I did not want to know I would not have asked.
I have no idea how much resistance power steering adds if any when the engine is not running
macafee2

[Al_B]

Jack the front up and pop the airbag out of the steering wheel. Then use a torque wrench to turn the wheel via the column nut. Starting off at the lowest setting and winding it up until it just doesn't click will give you the torque required. Then drop the car back on the ground and do it again to get the loaded reading. Simples.

Many modern cars use quite aggressive suspension and steering geometry which relies heavily on the power steering to control kick back and reduce the effort to manageable levels. Some years ago a customer had a power steering belt fail on a prestige car and was about to sue the manufacturer claiming the car was unsafe in the event of such a minor issue. The company responded by getting them to drive one of the development cars which had variable assistance and demonstrated that control was retained, albeit at increased effort. (as told to me by one fo the engineers)

[T-Cut]

Originally Posted by macafee2

Reason for my question, I was always taught not to turn the steering wheel when stationary as it puts a lot of strain on the steering components and can damage what is beneath the wheels. I'm trying to gauge how much of the steering resistance of our cars with the engine off is due to contact with road and steering components but not including power steering components.

Surely, the strain on the steering components as a whole is no different whether the engine's running or not? The effort needed to turn the tyres against the road surface is the same, so every component shares proportionately in that. The essential difference is in the effort you expend in turning the steering wheel. From that point down, the energy consumed is always the same. With the engine running, it provides most of the energy that you supply when it's off. The steering components are none the wiser - if you see what I mean. Watch the tyres when the steering's turned to full lock, when stationary/engine running. Lots of stressing and straining down there. I guess the rack/pinion gear is under a lower load, but that's all.

TC

[topman]

Originally Posted by macafee2

I'm just looking for a rough idea and thought someone may know.
If I did not want to know I would not have asked.
I have no idea how much resistance power steering adds if any when the engine is not running
macafee2

I'm just suggesting a way to find out for yourself if you are unable to find out the answer. Only reason I suggest a way to diy it is, it's not really something people would measure themselves.

[macafee2]

Originally Posted by topman

I'm just suggesting a way to find out for yourself if you are unable to find out the answer. Only reason I suggest a way to diy it is, it's not really something people would measure themselves.

not asking for an exact measurement but there are some very cleaver people here with much more knowledge them me and perhaps from their years of experience may have an idea.

I'd hazard a guess of not less then 80% but that's based on memory of cars from 145 plus years ago

macafee2

[macafee2]

Originally Posted by T-Cut

Surely, the strain on the steering components as a whole is no different whether the engine's running or not? The effort needed to turn the tyres against the road surface is the same, so every component shares proportionately in that. The essential difference is in the effort you expend in turning the steering wheel. From that point down, the energy consumed is always the same. With the engine running, it provides most of the energy that you supply when it's off. The steering components are none the wiser - if you see what I mean. Watch the tyres when the steering's turned to full lock, when stationary/engine running. Lots of stressing and straining down there. I guess the rack/pinion gear is under a lower load, but that's all.

TC

I'd kind of go with rack and pinion too. The rest of what you say is over my head

macafee2

[HarryM1BYT]

Originally Posted by macafee2

I'd kind of go with rack and pinion too. The rest of what you say is over my head

macafee2

The power assistance occurs at the rack itself, so with engine off and no assistance its unlikely muscle power alone would be putting as much strain on the rack + ball joints etc. as would occur with power assistance working [1].

What would come under much greater strain is the steering wheel and the parts between it as far as the rack.

[1] My Granadas with no PAS - I was unable to turn the steering wheel unless the car was rolling.

Knowing how much strain is involved, even with PAS, I make a point of trying to ensure a vehicle is moving before turning the steering wheel.

[macafee2]

I don't think people realise how much strain the steering and tyres are under due to power steering.

macafee2

[slovcan]

Originally Posted by macafee2

I don't think people realise how much strain the steering and tyres are under due to power steering.

macafee2

I don't think the steering and tires are under any more strain whether standard steering, power steering engine on or engine off. The effort to turn the steering wheel of a power steering equipped car with the engine off is likely 3 or 4 times more than a standard steering car because of the resistance of the dead hydraulic system. Hydraulic fluid is non-compressible so in order for the wheels to turn the fluid must move in the system. Engine running the power steering pump does this job. With the engine off the driver must put in enough effort to push the hydraulic fluid through the little ports, passages & valves.

Cheers,
Glenn