Today I was making a sharp turn at full lock in my week old 2017 F250 with adaptive steering and I heard a noise that at first sounded liked tire rub. When I came to a stop I turned the wheel to full lock both ways and got a loud static-like sound toward full lock going either direction. I have linked a video so you can hear the noise. Anybody else experience anything like this? My truck is going into the shop Tuesday to hopefully get fixed.

 

Says in the owners manual not to do that..

 

I only did the standing parked test after I heard the noise making a tight turn. I make a lot of tight turns at or near full lock in my day-to-day work. I hope that type of use isn't going to cause continual issues with the steering.

 

Mine will do the same at full lock or when my plow is attached. When plow is attached this noise can occur at any wheel position. Happens more readily when truck is cold. I have contributed this to the massive weight and load on front wheels, cold hydraulic fluid, etc. Haven't been bothered enough to care much.

 

It says when you hear the noise to just back off a little .... paraphrasing

 

Mine has done this since day 1, it sounds like a couple of rats are in there fighting it out. As soon as I back off just a hair it goes away. I had my truck at the dealer last week getting new front shocks and asked them to take a look at it and they said all is normal and even put it in writing that they checked it against a new truck on the lot and found the same thing. I think it has to do with the mechanical advantage system of the adaptive steering and the motor getting to a full lock, sort of like a loud power steering pump that can be heard in many trucks at full lock. Just the slightest back off takes the noise away for me and does not change the degree that I can turn the truck. I have a parking lot at work that you would not believe and I have to do some crazy ninja moves to get in and out of it so I get the chance to hear it more than most people maybe. If you need to get a 2017 Super Duty into a tight space, reverse is your best friend.

 

I have also heard this noise and did exactly as you paraphrased. I assumed it has to do with how the motor in the steering wheel makes up for the turning of the steering wheel less since this is not electronic steering and it is straining. This is also why it would happen with a lot of weight on the front of the truck.


One thought is ....how would this work if the power steering went out. Would you just be screwed?

 

Normal noise for me to since day 1. Just back off a hair and it disappears.

 

I downloaded the manual and found some information on pages 256 and 257. It does say not to hold the steering at full lock for more than 3 seconds when the engine is running. This warning is for all trucks and not just those with adaptive steering. I couldn't find any notice about adaptive steering related noise in the manual except that you may hear a lock engage or disengage as the system mechanically locks in a fixed steering ratio under certain conditions.

I have some other issues so I will take the truck in and see what the dealer has to say.

I appreciate all the feedback so far.

 

There are actually some sections in the owners manual that describe the warning messages and faults. It's not so much about the power steering failing but faults with either the adaptive steering motor or wheel position sensors that can leave you stranded. If the adaptive steering system can't tell that the wheels are actually pointing where the motor in the steering column thinks they should be pointing, it sets a fault condition.

 

Mine does that and I don't have adaptive steering.

 

Mine does this as well and I do not have adaptive steering.

 

It's not the adaptive steering, it's the power steering hydraulics you are hearing. When you hold the steering wheel at full lock you are basically telling the power steering system to keep turning when it can't turn anymore. This causes pressure to build rapidly in the system. The noise you are hearing is the pressure relief valve, without it, holding the steering at full lock would break things in a hurry. The reason they tell you not to do this for more than a few seconds is because, one, it's hard on the system and, two, it heats up the fluid pretty quickly. Hold it too long and you could boil your fluid.

Power steering has worked this way for a very long time, I'm surprised no one has heard this noise before.

Technical answer for those who care:

Under normal conditions, when you turn the steering wheel you are applying torque to the torsion bar (inner member) of the rotary valve via the input shaft, this causes the torsion bar to twist and rotate slightly relative to the sleeve (outer member). Sorry, lots of names their, I suggest searching google for a picture.

This twisting action is what controls the flow of power steering fluid. When the inner member twists it lines up with different channels in the sleeve, which in turn allows fluid to flow to different chambers, (power) turning the wheels and rotating the pinion/worm gear in the same direction as the input shaft. As the pinion/worm gear turn, torque on the torsion bar is released, allowing it to return to the neutral position, stopping the power assist. The harder you turn the wheel the more the torsion bar twists, allowing more fluid to flow, increasing the level of power assist.

When at full lock the wheels can't turn anymore, so the pinion/worm gear can't rotate to match the input shaft, preventing the rotary valve from returning to neutral. When this happens fluid continues to be directed into the full chamber, increasing the pressure and triggering the pressure relief valves. There are actually a couple of different configurations for the pressure relief valves, but this is probably already more then anyone wanted to know.

 

Yep....Screwy hit the nail on the head. I'm sure a lot have heard it before...as I have...and knew what it was....but just aren't here to comment.

 

Thank you for the detailed response. It is interesting that I have never heard this particular noise before, which sounds like static on on old radio, in any of my other trucks. I've heard a sound that is more of a whine in past trucks when at full lock. Also, when turning the wheel to the left in the video the noise started well before full lock. I guess this could be attributed to the fact I was turning while stopped which puts more load on the system.