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Discussion Starter #1
I have noticed I need subtle steering correction when I accelerate hard and then opposite correction when lifting off gas and a little more correction when braking. Acceleration causes the car to veer to the left slightly and I automatically correct by turning wheel right. Lifting off the gas, the car veers to right and I correct by steering to the left. I am only talking about a degree or 2 from a centered steering wheel, hard braking may result in an extra degree or so of additional correction.
I have witnessed this on other Alfas and other solid rear axle cars. Is this common on solid axle cars due to torque reaction? On acceleration the front of car body lifts and rear of car lowers also the left side lifts and the right side lowers. So the combined effect is the LF corner lifts and the RR sags other corners stay about the same level.
I should test what happens if I just use the parking brake?
Fairly low miles on the new front inner A arm bushings, new rear control arm bushings and pair of new conical t bar bushes, plus brand new poly thrust washers at t bar to body bushes. Had a look at my castor arm bushes they look surprisingly good but do flex a bit when pried at.
I posted the same Questions in the GT section but looking for more responses here.
 

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So it steers differently on the gas and off? Typically that means the rear end is steering under power. I'd look at the trailing arm bushings for wear.
Andrew
 

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Discussion Starter #4
Just checked the tightness of trailing arm bolts, seems ok. Not something I am likely to forget (proper torquing).
 

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Discussion Starter #5
Video of left rear wheel in action on the road.

Left rear wheel in video.

 

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Brad,
I would be inclined to suspect a front suspension toe pattern issue, in which the right and left toe angles do not change equally as the suspension moves vertically.
Unfortunately, it is not easy to diagnose this without the ability to vertically load and unload the front end on a wheel alignment rack.
As a first check, carefully inspect all the steering components. Is the center link dead level in the car? Are the left and right tie rods equal in length stud to stud?Is there any sign of distortion and straightening on steering arms, idler arm, or steering gear drop arm?
Is the vehicle within spec for suspension height, or if it has been lowered are the heights equal side to side?
Basically, you are looking for anything that is unsymmetrical side to side in the steering or suspension systems.

Joe Bartusek
 

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Discussion Starter #9

I thought I would see something with the left rear wheel moving forward on acel and rearward on decel. Maybe it is to small to see or something funny with right front. Here is RF video looking forward.
For some of this video I held the wheel straight and gassed and released in 2nd or 3rd, you can see the car self steer. Watch the 35 sec to 55 sec on video.
I am not sure I am learning any thing with these videos other than how to operate the camera and upload to U tube and download to ABB.
 

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Whenever I've had this symptom, it has been a rear trailing arm bushing. You generally cannot see the failure with the arm bolted in place. It doesn't take much for the rear axle to move forward or rearward under acceleration, and as it is likely to be one bushing that failed before the other, this introduces steering one way under acceleration, and the other on deceleration. It's a bit of a nuisance, but if your car has enough age and miles on it, just drop the two rear arms and replace the bushings. Not an easy job, but ultimately worth doing.
 

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I would bet that your caster angles are different. Load/unload front (i.e. decel/accel) with different caster angles would affect toe and correspondent "gain" for steering angle. A good alignment tech will be able to read the static values for less than 30 minutes labor, and a better alignment tech will be able to diagnose and correct the problem quickly.

The tech I send my transaxle cars to is quite good. I observe him bouncing the car rather aggressively to check dynamic (as best as possible) values while another tech watches the values from the display on the laser rack. I had a similar issue (on/off throttle steering inconsistency) that was corrected with careful front end adjustment. Bring some ballast if you want the alignment done with your weight in the driver seat.
 

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Discussion Starter #12
Tried looking for lower ball joint movement, awkward with wheel on. Found a bill for rear trailing arm and conical T bar bushings. Year 2000 only 11000 miles since then, wouldn't think they would be worn out. Found some spare used trailing arms in garage likely 46 years old, look dry but doubt they would even allow any rear steer. The dilemma continues.

If I had different castor angles then the car would pull at cruise, wheel with more castor would pull to center of car.
 

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Discussion Starter #13
I likely should concentrate on suspension items not replaced by myself since I bought it in 1984 and 56000 miles ago. Front upper control arm (inner bush, castor bush, upper ball joint) and lower ball joint have been untouched by me. I should put a dial indicator on the ball joints and check.
 

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I too would look at the rear trailing arm bushings, you can't see anything by looking at them, but apply a load to them by means of a pry bar and if there is substantial visual movement I'd replace them.
 

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Discussion Starter #15
Video of LR trailing arm front bushing. There is movement of arm back and forth on accel, decel and brake. Now I need to see if right side is the same or substantially less. Hopeful I have found it, but wonder if the bushings I put in 16 years ago were crap or is this what to expect from rubber? Maybe go poly in this location? Pros vs cons?

The 1 minute mark and onward is the best.

 

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Discussion Starter #16
Right rear trailing arm, front bushing

Video rr trailing arm front bushing.

 

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Discussion Starter #17
I think these 2 videos taken on the same road in the same hour should be a better pair to compare movement of the bushings left & right.



Can anyone see one side move more than the other?
 

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bottom video. Sounds like she's running nice
 

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Discussion Starter #19
You think the bottom video ie the left trailing arm moves more? I also think left side moves a little more.
 

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Discussion Starter #20
The other 2 videos I made yesterday to compare left to right bushing movement.
In the last 4 posted videos I paused the videos showing extremes of movement and measured with a ruler. I get about 20% more movement on the left bushing. Which could explain the self/rear steer.
 
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