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Old 02-06-2019, 12:58 PM
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Default Taurus AWD changes alignment under load

Backstory - Was looking for a solid winter beater to replace the one my son took away, so my other son grabbed me a 2015 Interceptor AWD at auction. Standard ex-police car - 190km (115Mi) - seat shredded due to utility belt, rode hard, holes where lights were removed. But full maintenance records, everything works, goes like stink, and price was right i.e. dirt cheap.

It has a handling issue I can't figure out. Every time "extra" power is applied, the nose of the car shifts left.
Driving at 40-50 - stomp pedal - nose goes left 1-2" - let pedal up - back to the right.
Highway at 65. Base of hill - start up hill - constant speed - nose shifts left going up - crest hill - nose back right.
Doodling along backroad at 40 - nose will occasionally shift left then back right as more or less power is applied.
Easily reproducible - happens every time "more power" is applied.
It feels like the alignment is shifting under load. It ALWAYS comes back when the load comes off. The car seems to drive straight - the body just points a different direction.

I've googled it and found one reference to similar symptoms on a FWD version of the same car - so far no solution posted.

So far I have
1) Tugged on all tires top/bottom and side/side with no noticeable movement at any wheel
2) Removed front wheels and used a pry bar at the control arm pivots with nothing moving. Same with ball joints.
3) Checked sub-frame bolts for looseness or any sign of movement.
4) Inspected everything in the front for any signs of "movement" .
5) Checked tie rods and stabilizer links.
6) My son inspected the back end with a pry bar too - did not find anything.

I'm not sure what to check next.
I realize that the car is AWD, and the computer is controlling power to the rear wheels (off under light load, on under heavy load) so that could be a factor for me (but not the other guy), but I'm not sure how or what to check there. There are no warnings or alarms etc.

I'm getting tired of rolling around on the cold cement without finding anything. The issues is definitely there - and there is enough change in "direction" that there has to be something moving noticeably. But I'll be damned if I can find it.

Any ideas?
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Old 02-06-2019, 03:40 PM
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Kind of out of left field but check the motor mounts and the frame up front. I'm assuming its a rack and pinion steering and could see that getting shoved sideways if the motor was shifting under torque
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Old 02-06-2019, 04:44 PM
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I know nothing about it but I would look toward the rear right. I believe that is the drive wheel and if it slips back some how you would pull to the left.
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Last edited by digr; 02-06-2019 at 04:53 PM.
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Old 02-06-2019, 07:46 PM
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Quote:
Originally Posted by Matt Shade View Post
Kind of out of left field but check the motor mounts and the frame up front. I'm assuming its a rack and pinion steering and could see that getting shoved sideways if the motor was shifting under torque
I would suggest checking themotor mounts as well. Put it in gear with the brakes on and give it some gas. With the hoodip it should be easy to see. Also wonder it torque steer is coming into play?
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Old 02-06-2019, 08:54 PM
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It's definitely not torque steer. Apply power and it shifts over and stays over until power is reduced. Do not need to be accelerating.
It's going tomorrow to a friend that works for a Ford dealership. See if he has seen something similar before.


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Old 02-06-2019, 10:46 PM
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I would remove, inspect and torque every bolt on the front a arms or struts. Sounds like you have a lower a arm moving around.
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Old 02-06-2019, 11:03 PM
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Quote:
Originally Posted by SmokinDodge View Post
I would remove, inspect and torque every bolt on the front a arms or struts. Sounds like you have a lower a arm moving around.
+1.... I'd bet on that as well... got a chevy in today doing the same thing
lower control arm bushings and strut tower are bad nd ball joints are a bit questionable also...
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Old 02-07-2019, 08:51 AM
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There is a strut rod that goes from the front axle left to right across and anchors to the frame on 4wd trucks. I have forgotten the name of it, but if the bushings in the ends of that rod wear the body will seem to slide around on the road when driving.
Don't know if AWD rigs are the same, but probably
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Old 02-08-2019, 10:52 PM
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Quote:
Originally Posted by SmokinDodge View Post
I would remove, inspect and torque every bolt on the front a arms or struts. Sounds like you have a lower a arm moving around.
THIS ^^^^ was the first thing that popped into my mind. Try prying on things with the wheels on the ground. With the control arms "extended" down, it may be tightening up the bushings enough that the pry bar won't find any looseness.

Check the torque strut also. Do this when you check the motor mounts. With engine running, someone in the car foot on brake and foot on gas, giving it a little gas check for excessive engine movement. Do it in reverse also...
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Old 02-08-2019, 11:09 PM
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I was in the motor mount crowd. I think SD is on point about the A-arm theory. Something is flexing and irregardless of where it is coming from. You need an observer outside watching the show under power. The ideal situation in my mind is sitting on an old school pit with someone in the pit. Lock the front end enough to brake torque the MF and stand on it . My guess is you won't need Day-glo paint when it shifts sideways 3"
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