Steering misaligned under load

[Cptnjack]

So I’ve been chasing this issue for a bit over a month, when I accelerate moderate to hard the steering wheel will **** and be misaligned, turned to the right 7-10 degrees and under braking or slight deceleration it will “pop” back.

So from the beginning, I bought this car for 3500, the guy said he would drive it to Texas he’s so confident in it. Ran a bit rough but I worked out the running bugs. In comes the Wisconsin snow and when it hits any kind of slick on the road I could feel the front end moving almost like the subframe is disconnected. I put it on stands and found the ball joints were almost non existent. It had that strut thud when turning so I go ahead a just do the front end work.

What I replaced; lower control arms, inner and outer tie rods, sway bar links, struts then got an alignment. It was fine for a day but then it started jerking and the steering wheel would go out of alignment. I figured this has to be mechanical because it’s always the same, accel-****, steering wheel out of alignment, decel-****, steering wheel back to straight.

I checked the spindle knuckles for play, I checked the inner and outer tie rods to make sure they weren’t bad, I checked the subframe mounts and made sure they were tight and not rusted and finally I changed the EPAS rack and pinion (thought maybe it was a torque sensor failing). I calibrated it and everything took, no issues there, it feels like it might still be doing it, I have an alignment scheduled for Friday again after changing the rack and pinion but I want to do more digging in case that doesn’t work.

The only other thing I can think to do is change the wheel speed sensors? Do these talk to the EPAS and tell the torque sensors to correct or adjust in case of slippage? Maybe my car thinks it’s sliding on ice because the sensor is bad and the EPAS is trying to correct? Any ideas or thought would be greatly appreciated! Thanks!

 

[Cptnjack]

As a side note, tomorrow I’ll be pulling up FORScan to watch all my wheel speed sensors as well as the steering angle sensor and EPAs torque sensors, is there any else I should be watching?

 

[kryptto]

i will address this this way since you seem to have attacked the electrical and direct unit and lets assume its nothing you replaced I think you would be seeing other more severe issues.

I have zero knowledge of miles, condition other than in a snow state which worries me and the cars history. Hopefully a SHO, and may or may not be a Performance Package. Details might help when it comes to PP parts.

The "Subframe Shift" (Most Likely)
Rear Suspension
PTU and Engine Mounts

The car has a PTU for the AWD system. If the Rear Engine Mount (often called the torque strut or roll resistor) is just shot, the engine and transmission will tilt significantly under hard acceleration.
Next: If a wheel speed sensor was bad, it would trigger an ABS/Traction Control light and potentially "kick" the brake pedal via the AdvanceTrac system. It would not physically hold the steering rack at a 10-degree offset and then let it "pop" back. That is almost certainly a physical component moving that shouldn't be IMHO.

Lastly, Check the Rear: Inspect the rear toe links and bushings. Subframe Bolt Torque: Don't just check if they are "tight"; verify they are torqued to spec (the SHO subframe bolts are notorious for needing a massive amount of torque). Do a visual torque test: (PLEASE BE SAFE HERE) I had seen on the ecoboostperformance forum, with the car on the ground, have someone blip the throttle in gear (holding the brake) while another person watches the front wheels and subframe for movement.

If they find the subframe is shifting, they might need a subframe alignment or just new, high-quality bushings. https://ebay.us/m/GXhynl

Just some thoughts.

 

[Cptnjack]

thanks for reply!

I’ll check the torque on the bolts, my thought was something mechanical as well but I’m just not seeing it. It is a sho and I don’t think it’s the PP, it felt almost as if the spindle shifted at the tie rod and the other wheel compensated from ground friction to go straight, my thought is that would cause the wheel to be off because the tow is pointed inward on both driver and front, that pointed at the drivers side but I couldn’t find anything there. I’ll have to try the subframe torque test, I wonder if disconnecting the rear drive shaft would allow only the front to move or if it will just spin there being the path of least resistance.

 

[Texas Marauder]

The car will just be a normal FWD if you remove the driveshaft.

 

[Cptnjack]

So I started looking at everything and I didn’t see any problems so I decided to look over the subframe to make sure it isn’t bent or cracked anywhere and it all looked good, the only two bolts I havnt taken off were the subframe front bolts, I checked they were tight but never pulled them off. The drivers side broke so I’m wondering if it wasn’t completely tight. I’ll likely have to drop the subframe to drill it out but fingers crossed this will be the fix!

 

[Cptnjack]

some bad news, while working on the subframe I noticed my ac condenser was bent in, further inspection showed the intercooler and radiator also bent, found the bracket the mounts the plastic core supports on the passenger side was bent back a ways, same for the drivers side but not as far. Pulled the car fax, I know I should have done before buying but its more of a project vehicle, found it was in an accident a month before I bought it. no info other than "minor accident" so Im assuming he hit something and didnt like the way it was driving so he off loaded it. So the new plan, engine and tranny are coming out, subframes coming out and ill be inspecting it, ill give everything a good cleaning and take care of any rust, and get it all back together with a bunch more new parts. what a headache!

 

[kryptto]

ok well now you know and unfortunately the insurance companies would back in the day of higher resale value as a write off for a front end accident.

 

[Cptnjack]

It has a clean title, so that’s a plus. I just wish the guy would have said something so I didn’t go spend a bunch of money chasing a ghost.