Persistent Pull to the Left

[Maver1ck]

I am struggling to diagnose and repair a persistent pull to the left on my '68 Kombi. For as long as I have owned the car (6 years as my daily driver) it has driven perfectly straight, until recently.

About 3 months ago, I replaced all suspension bushings on the entire car, front and rear. A few weeks after that, out of nowhere, I got a serious pull to the left. Strong enough that I need to actively steer to the right about 20 degrees, and with some effort, to keep the car going straight. If I were to let go of the steering wheel I would be in the ditch in one second flat.

When the pull first occurred, I took it to an alignment shop. They noted the front left wheel had almost 2 degrees positive camber and they suspected my bearing was bad. At the same time, it appeared at least one of my front calipers was partially frozen. So, to remove all doubt, I replaced both hub/rotors, calipers, pads, and bearings. I also installed new front springs at the same time. Every single tie rod end and ball joint was checked. I rotated the tires. I ensured each was exactly at 30 PSI.

And still, the pull persisted. When I returned to the alignment shop, the camber was still 2 degrees positive. So I showed them how to use shims on the upper A-arm to bring the camber back to zero. The alignment computer said "all good!" yet it still pulls to the left.

I have just today deconstructed and reconstructed the entire front left suspension (removing and inspecting both A-arms and bushings to see if one had already collapsed or if the A-arms were visibly bent or is something was not torqued properly (nope). I thoroughly inspected the cross member / shock tower for any indicated whatsoever of a crack or bend. Nothing.

The brakes do not affect the pull at all. Rear brakes have been adjusted to perfection and front brakes are all brand new.

I am at the end of my diagnostic skill level. Any ideas on where to go from here (aside from the ditch)?

[Rustinmotion]

If you lightly apply the brakes do you feel it pull or does it only happen on harder brake input
Either something in the suspension is loose enough to alter geometry during weight transfer or front or rear left side brakes are grabbing sooner or harder than right side after a long light brake to a stop do the drums/ discs feel hotter on one side than the other?

[Derek UK]

Make sure that the Pitman arm on your steering box is in the correct position on its spline. After you take the nut off you should be able to see 2 witness punch marks and they should line up. Forget the steering wheel position and make sure the alignment is done with the Pitman arm pointing straight ahead. Check the idler bush before alignment. If worn, setting the toe in can make it out of line. Re position the steering wheel after you are happy with the alignment. Of course none of this may work! Calliper drag due to stuck pistons is common but you say you have replaced them. I was going to suggest doing a temp test after a run which has plenty of braking. Dragging side will be hotter than the other. Check the back ones as well. Sticking handbrake can also cause problems.

[Maver1ck]

Thanks for the tips.

Looking at my timeline again, I noticed I actually replaced the suspension bushings and springs on March 3. I then visited the alignment shop on March 8, meaning the pull was immediate, not a few weeks later as I originally stated, so it may have happened as a direct result of that suspension work.

I wonder, could a bent lower A-arm cause the issue of positive camber? I used an 80-ton shop press to remove the 55 year old bushings and install new ones.
The old ones were difficult to remove and the new ones seemed maybe .5mm too large for the existing holes in the A-arm, so I filed the holes a bit to make them fit. Perhaps I bent the lower A-arm in a way that is not perceptible when looking at it? When the camber was corrected at the upper A-arm, perhaps the bent lower arm is still off enough to cause a pull?

On some alignment machines, they turn the wheel left and right. On this machine, the wheels stayed straight ahead as they rolled the car back and forth. Perhaps with a different machine the issue could be seen more readily?

I will gladly check the pitman arm, but I didn't remove it during these adventures and the car tracked straight right up until I installed new bushings and springs.

I wonder, could my new springs cause the issue, if they are slightly different heights? I have not yet tried swapping the springs left to right.

I don't think it is the brakes, as the pull happens all the time and does not respond differently depending on brake input. There is no dragging on the front or rear wheels.

[Rustinmotion]

Do both steering arms point forward when the wheels point forward?
Can you check for equal toe in with a length of string?

[142 Guy]

A lot of things to respond to so this may not be in the best order.

If you had to show the alignment shop how to use shims to correct the camber that is a bad sign. The shop is clearly not familiar with methods of alignment on vintage cars. Alignment 'computers' have trouble with vintage cars and I would be inclined to trust the old school manual alignment procedures unless your alignment shop techs really understand what is going on as opposed to just making the adjustments that the computer tell them to do.

I did a basic alignment on my 140 - starting in post #387
https://www.swedespeed.com/threads/w...201780/page-20
With a straight edge and one of those little electronic levels it is relatively easy to do a basic camber check. The electronic levels are nice because you can set your zero reference to account for a garage floor that is no longer level.

When the shop moves the car back and forth on the machine they do that to establish that the car is steering straight ahead and the suspension is in a neutral position. Any compression in the suspension affects camber measurement. At that point they can directly measure the camber. The procedure where they turn the wheels left and then right (typically + and - 20 degrees) is used to measure the caster and can also confirm toe-out. If they were just checking camber they would not have to do the left - right measurements.

I suppose that a differential camber of 2 deg+ on the left with zero on the right could cause a pull to the left. initiating positive camber is effectively how motorcycles steer by initiating a roll to the left or right. For my 140 Volvo specs a maximum positive camber of +1/2 deg with the implied requirement that the left and right camber are within 1/2 deg of each other. I have never experienced a 2 deg differential so can't comment on what that would be like. I would be inclined to do my own basic camber check first. If it is out try adjusting to see if you can at least bring the camber values so that they are within 1/2 deg of each other. If your left and right cambers are within 1/2deg of each other and you still have a significant pull to the left I think it is time to move on to some other problem area.

Your comments about the possibility of bending the A arms depends on which plane you bent the A arms in. If you bent the A arm so that the vertical alignment of the kingpin / steering knuckle has changed I think shim adjustment will bring the camber back to the setting point; however, the camber change that occurs during normal suspension movement may no longer be what it was. I don't know whether that is a big problem and I don't know that it would cause a steering 'pull'.

If you bent the A arm in the horizontal direction so that the front - back alignment of the kingpin has changed that could conceivably cause a pull. However, I would expect that kind of error to show up directly in the toe-in measurement. You may be able to adjust the toe to bring it back to zero or slightly positive; but, I don't know that correcting the toe value would actually correct the problem.

While on the subject of toe-in, I notice that you have made no mention of toe-in values in your posts. Have they actually checked toe-in values? When it comes to steering pull, that would have been one of the first things that I would check. With a tape measure (a collapsible measuring rod is better) you can do a basic toe-in measurement. If you correct the toe using the tie rod this will become an iterative process because the toe in measurement is only valid when both wheels are steering straight ahead (the toe measurement changes as you steer because of designed in toe-out). You need to measure, then adjust and then move the car back and forth to try and get the car back into a steering straight position and then check the toe measurement again. If it is out adjust again, roll back and forth and then measure.

If the toe requires significant adjustment then you may end up with the steering wheel in the not straight ahead position when the toe-in is at zero or slightly positive (wheels straight ahead). The pitman arm and the steering box may also no longer be centered. On my 140, the pitman arm and steering box have no registration marks. As per the service manual you need to mark them before dis assembly. If your Amazon does not have registration marks and you did not add them during removal then you may have an iterative process of getting it back together. Getting the steering wheel corrected is an easy process of just removing it and shifting it on its splines; but, that may not leave the steering box centered. With the wheels pointed straight ahead, you want the steering box centered so that it is an equal number of turns from the straight ahead position to the left and right. So, get the toe in set correctly with the wheels steering straight. Detach the pitman arm and make sure that you have the steering box in the centered position (a paint mark on the input shaft helps as a registration point once center is established). Re attach the pitman arm with steering box and front wheels in the presumably straight ahead position and then recheck your toe to make sure it hasn't changed. Adjust your steering wheel on the splines so that its appearance is correct.

[Rustinmotion]

Originally Posted by 142 Guy

A lot of things to respond to so this may not be in the best order.

If you had to show the alignment shop how to use shims to correct the camber that is a bad sign. The shop is clearly not familiar with methods of alignment on vintage cars. Alignment 'computers' have trouble with vintage cars and I would be inclined to trust the old school manual alignment procedures unless your alignment shop techs really understand what is going on as opposed to just making the adjustments that the computer tell them to do.

I did a basic alignment on my 140 - starting in post #387
https://www.swedespeed.com/threads/w...201780/page-20
With a straight edge and one of those little electronic levels it is relatively easy to do a basic camber check. The electronic levels are nice because you can set your zero reference to account for a garage floor that is no longer level.

When the shop moves the car back and forth on the machine they do that to establish that the car is steering straight ahead and the suspension is in a neutral position. Any compression in the suspension affects camber measurement. At that point they can directly measure the camber. The procedure where they turn the wheels left and then right (typically + and - 20 degrees) is used to measure the caster and can also confirm toe-out. If they were just checking camber they would not have to do the left - right measurements.

I suppose that a differential camber of 2 deg+ on the left with zero on the right could cause a pull to the left. initiating positive camber is effectively how motorcycles steer by initiating a roll to the left or right. For my 140 Volvo specs a maximum positive camber of +1/2 deg with the implied requirement that the left and right camber are within 1/2 deg of each other. I have never experienced a 2 deg differential so can't comment on what that would be like. I would be inclined to do my own basic camber check first. If it is out try adjusting to see if you can at least bring the camber values so that they are within 1/2 deg of each other. If your left and right cambers are within 1/2deg of each other and you still have a significant pull to the left I think it is time to move on to some other problem area.

Your comments about the possibility of bending the A arms depends on which plane you bent the A arms in. If you bent the A arm so that the vertical alignment of the kingpin / steering knuckle has changed I think shim adjustment will bring the camber back to the setting point; however, the camber change that occurs during normal suspension movement may no longer be what it was. I don't know whether that is a big problem and I don't know that it would cause a steering 'pull'.

If you bent the A arm in the horizontal direction so that the front - back alignment of the kingpin has changed that could conceivably cause a pull. However, I would expect that kind of error to show up directly in the toe-in measurement. You may be able to adjust the toe to bring it back to zero or slightly positive; but, I don't know that correcting the toe value would actually correct the problem.

While on the subject of toe-in, I notice that you have made no mention of toe-in values in your posts. Have they actually checked toe-in values? When it comes to steering pull, that would have been one of the first things that I would check. With a tape measure (a collapsible measuring rod is better) you can do a basic toe-in measurement. If you correct the toe using the tie rod this will become an iterative process because the toe in measurement is only valid when both wheels are steering straight ahead (the toe measurement changes as you steer because of designed in toe-out). You need to measure, then adjust and then move the car back and forth to try and get the car back into a steering straight position and then check the toe measurement again. If it is out adjust again, roll back and forth and then measure.

If the toe requires significant adjustment then you may end up with the steering wheel in the not straight ahead position when the toe-in is at zero or slightly positive (wheels straight ahead). The pitman arm and the steering box may also no longer be centered. On my 140, the pitman arm and steering box have no registration marks. As per the service manual you need to mark them before dis assembly. If your Amazon does not have registration marks and you did not add them during removal then you may have an iterative process of getting it back together. Getting the steering wheel corrected is an easy process of just removing it and shifting it on its splines; but, that may not leave the steering box centered. With the wheels pointed straight ahead, you want the steering box centered so that it is an equal number of turns from the straight ahead position to the left and right. So, get the toe in set correctly with the wheels steering straight. Detach the pitman arm and make sure that you have the steering box in the centered position (a paint mark on the input shaft helps as a registration point once center is established). Re attach the pitman arm with steering box and front wheels in the presumably straight ahead position and then recheck your toe to make sure it hasn't changed. Adjust your steering wheel on the splines so that its appearance is correct.

Just to add to this valuable info, it’s important to make sure idler arm and steering arm are parallel when wheels are pointing dead ahead

[Derek UK]

You don't need to take off the Pitman arm nut to check the witness marks. My bad. Shown here in the pics.
The toe is set by twisting the centre rod between the Pitman arm on the box and the idler arm on the other side. When the ball joints are renewed on the rod they are different on each side. RH and LH thread so twisting the rod moves the two arms closer or further apart. The joints should be marked R and L to differentiate them. 2 of the same part number will fit but won't adjust the toe. Make sure that the 2 arms are both pointing straight forward. Both of the joints when screwed into the rod should both be in the same number of threads before you fit them to the arms. Screw to about the midpoint of the thread so that you can allow toe in and out. If this rod has been adjusted recently the nuts should unscrew easily. If not give them a blast or two of penetrant to keep the mechanic happy. They are often rusted stuck. Some phones will give you a camber angle.
https://www.youtube.com/watch?v=nR19cStTX_E

Some notes here. Play the little video. There are also some suggested alignment settings that you may want to consider. Changes are about the same as suggested by Rob at Amazon cars.
http://volvo-122s.blogspot.com/2014/06/

[142 Guy]

Originally Posted by Derek UK

Some phones will give you a camber angle.
https://www.youtube.com/watch?v=nR19cStTX_E

http://volvo-122s.blogspot.com/2014/06/

If you have a cellphone and the app that should work if the app has a zero reset function to correct for a non level garage floor. As per the video, using the sidewall of the tire for measuring camber might be OK for a 'quick and dirty' check, I would not want to do that for measurements if I was making adjustments. The rim edge is the preferred choice providing the rims are straight. I am not sure that checking against a spirit level would qualify as a NIST approved calibration. I might skip that bit.

Entertaining video of the presenter on the track. He was making a fair amount of use of the adjacent non track areas in the corners. Perhaps needs to spend less time talking and more time concentrating on his entrance to the corners?

[Norcat]

There is a third angle in steering geometry that has not been mentioned and that is King Pin Inclination, this is the angle of rake between the upper and lower control arm balljoints as seen from the side of the vehicle. A bit like the angle of the forks on motorbike, they are angled forward at the lower end to give stability and self centering.
If you somehow bent the contol arms in the horizontal plane when replacing the bushes then the KPI will have changed and this directly affects the self centering function of the steering. This is checked when doing the left to right swing on the alignment machine.