My dealer just told me he received a TSB on the steering/brake problem. I've got a '99 F350 SD CC LB V10 Auto 4x4 and it does have the problem. I contacted Ford's Customer Service Center and told them about the problem and they in turn called the dealer I take my truck to for service. My dealer then called me and my truck is now there for a possible repair. Ford does know about and does acknowledge the problem. There are a couple things the dealers can do but I'm not sure of the details yet. Has anyone had any luck with a fix yet?

 

I just called my dealer after reading your message. He was not aware of a TSB on this problem. Once again he is calling Ford. I wonder if he'll call me back this time. Thanks for the info.

 

Well, scratch the pevious post of mine. I just picked up my truck from the dealer and he told me that the TSB is for the diesel trucks, not the gas motors. He thought I had the diesel when I talked to him on the phone prior to me taking my truck to him, I have the V10. He said what I'm experiencing when I put the brakes on hard while I try to steer is the following: When you turn the steering wheel the tires actually turn (roll) a little bit. The more you turn the more they need to roll, but still slightly. This has to do with the steering geometry. When you apply the brake firmly, the tires cannot roll thus acting against the effort to steer. I do have a little education in the automotive field. (I have an A.S. degree in Automotive Technology from a local junior college but that was many years ago and I will admit I'm a little rusty on things.) I think he might be right but I'm going to look into it more.

 

The physics of the rolling of the wheel while turning are quite interesting. Makes sense when you first think about it, but then I have a few questions about it.

If no turn is due to braking (brakes not allowing the tired to move) then this must happen for every vehicle out there (it has to be physically the same for all models). I have a buddy that has the Super Duty 4X4 with the same problem. Mine is a F250 4X4 (not Super Duty) and I have not experienced this problem. Yes, his weighs more, but the motion of the wheels should be quite similar.

Personally sounds like someone is trying to get you to shut up for a little while. Remember that the squeaky wheel gets the oil.

 

All,

I will add my opinion here as I think I can help resolve this a little. I have a '00 250 SD CC LB on order so my experience it limited to test drives and other solid front axle Jeeps I have driven. Anyway, the issue brought up about all cars not having the similar binding problem with the steering and brakes applied does is not valid since there are many different kinds of suspensions in use. I have a '95 Cobra that pivots on the center of the tire when the wheel is turned. Therefore, no matter how hard I press the brakes it will not effect the effort required to turn the steering wheel since the tire does not need to rotate. This is how the F150/F250 light duty truck suspensions work with it’s SLA. This is the same case in most suspension systems.

On a solid axle vehicle, the wheel actually travels on a small arc during the lock-to-lock steering travel. This requires the wheel to rotate in order to perform this change. At least this is how it worked on the Jeep I used to drive and I am fairly sure it is how it works on the Ford. The steering wheel would get locked in place when plowing from time to time on the Jeep since the front wheels could not travel back and forth, being locked in by snow. The only way to turn the wheel at that point was to spin the tire and jerk the wheel back and forth until the snow was cleared. This was a major pain in real tight spots. I really never thought about it before I read this forum topic since it never caused any real problems, but took some getting used to.

Here is a little test to see if the problem is just caused by wheel/tire bind for someone with a truck that has the problem: Park the truck on a slippery flat surface (ice) and see it the wheel still locks. If the lot is icy the wheel should go lock-to-lock since the tires will simply slide on the ice, but it will probably still be hard to turn the wheel. This test may work on a sand cover road/lot or even in some thin mud, but I am not sure. If anyone tries this let us know what happens.

I believe that the problem that you have all described is a result of the solid front axle and good brakes.

Hope this helps clear this up a little. I know it does not solve any bodies issues with the problem, but maybe it will make some feel a little better about it.

 

Makes sense to me. I also have a '00 F-350 SD CC Lariat 4X4 PSD LB SRW on order and am concerned by these posts.

thanks for the info

ed

 

For whats it's worth, I heard somewhere that the problem is related to not enough vacuum supplied to the booster. Supposedly a Ford engineering screw up. My 00' Super D does it too. I have driven alot of straight axle, front disc 4x4's and never had this trouble. Hmmmm?

 

>For whats it's worth, I heard somewhere
>that the problem is related to
>not enough vacuum supplied to the
>booster. Supposedly a Ford engineering screw
>up. My 00' Super D does
>it too. I have driven alot
>of straight axle, front disc 4x4's
>and never had this trouble. Hmmmm?


John,

I read the post claiming the vacuum as well. Problem is that does not work as a valid point to me either. The power steering pump is driven by the engine via drive belt. Vacuum would have no effect on the steering pump. I do know that the power steering pump on the 4.6L supplies both brake and steering pressure on Mustangs, since there is not enough vacuum. I believe the steering pump either supplies all the braking or assists the braking on the Super duty gas engine, I have no idea what the diesels use but they have the problem as well. So with full brakes on there may not be enough pressure left to perform the steering task while the truck is stopped and at idle. This could be tested by bring the rpm’s up to 2K and see if the problem still exists at a stop.

The hydroboost, what Ford calls this braking system, provides a great deal more brake pressure than the old vacuum based system used on the old push rod engines This may be the reason the new trucks have the problem. The level steering pressure required to overpower the brake just may be to high. The hydroboost system caused a great deal of brake line failures on Mustang on the road courses. All '96 Mustangs must upgrade to stainless steel braided lines to get on the track as a result.

Once I get my truck I will play with it a little and try to figure it out. I have spent a great deal of time modifying/replacing Mustang suspensions so believe I can figure this one out as well. I do not think there will be a fix for the problem unfortunately.

Later, G