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Get Yourself in Alignment - Part II

By Jim Lunson, tech committee

 

I went over last month how to do a good front end alignment on an MG. The next step after doing this task is to make sure the steering wheel is aligned with the road wheels. There is nothing more disheartening than to be out cruising down a long smooth straightaway only to notice that as the car tracks beautifully straight ahead in perfect alignment, the steering wheel is cocked to one side or another. Try to straighten up the steering wheel and the car veers off to one side. Not a pretty feeling and once you notice it will drive you nuts. The obvious solution to this problem is to match the steering wheel going straight ahead with the alignment of the front wheels. It will be explained here.

The first step in this process is to insure that the steering wheel is set properly on the steering column. Most MGs have a mark on the end of the steering column shaft which should point straight up when the car is going straight ahead. This can be checked by removing the steering hub and cover assembly and looking at the end of the shaft where the large center bolt holds the steering wheel in place. The steering wheel should be pointed straight ahead when this mark is in the 12:00 position. Often, sometime in the past, a shortcut process to center the wheel may have been done by simply pulling the steering wheel off and rotating it on the splines to match the track of the tires. This fixes the problem but is not a good solution as the steering rack is then not evenly spaced, meaning the turning range is unequal, going left to right. You will have three turns to one side, but only one to the other, causing problems when you need to make a sharp turn somewhere. You will either turn the wheels too far causing damage or wont be able to turn sharp enough to make the turn you need to. So check this and see if this has been done in the past. If so, the first thing to do is pull the steering wheel and get it on the splines accurately: showing perfectly straight ahead when the mark is straight up.

If there is no mark on the shaft, then the task is more complicated as you have to get under the front end and see if the tie rods protrude approximately the same length from the rack when the tires point straight ahead. If the steering wheel is incorrectly set, different lengths of the tie rods will be very evident. It does not take but changing the splines one notch to show a marked difference in tie rod lengths. So take a look and make sure they are equal. This can also be checked by turning the steering wheel and counting the revolutions from the straight ahead position to the end of the turn. The steering turns should be about the same in both directions.

One other rare problem occurs if the steering pinion (the shaft from the steering rack up to the universal joint joining the steering column) has been removed and reinstalled. Errors can occur if the pinion has been inserted incorrectly either into the rack or into the splines on the u-joint. Misalignment here when things were assembled together can occur. This is rather complicated to correct, but happens only rarely. It will throw off the steering wheel alignment severely however, when everything else looks perfect. If there is no way to align the steering wheel with the protruding tie rods being close to equal in length, then this may be the problem. So check to tie rod lengths first.

Assuming the steering wheel is only off roughly 45° or less, and the tie rods are about equal in length when moving straight ahead, the next step is to determine which way the alignment needs to be adjusted to get it straight with the steering wheel. If the steering wheel tilts to the right when the car is moving straight, then when the steering wheel is straight, the car would track to the left. The tie rods are connected to the wheel assembly in front of the pivot pin, so this situation would mean the left tie rod is too long and the right one is too short. The reverse applies of course if the steering wheel points to the left. So look at the steering wheel when moving straight ahead and determine what which side has to be shortened and which has to be lengthened. Its basic geometry to get the wheels pointing straight ahead.

The next step is to make the corrections, being careful to maintain the proper alignment which we did last time. The easiest way to do this is to adjust each tie rod lengths one complete turn at a time. Place a horizontal mark on each tie rod so you will know when it has been turned one complete revolution. Then loosen the jam nuts and make the correction to each side, shortening the one side (thread it into the outboard end closest to the wheel) and lengthening the other side by unthreading it. Do each side one revolution at a time. Then take the car for a short test drive to see if the problem has been fixed. If it has, you are finished and can retighten the jam nuts. If the car still tracks to one side, repeat the process with another complete revolution of each tie rod. If the tracking has been made worse, you adjusted the tie rods backwards and need to go back and turn them in the opposite direction two turns (one to correct the mistake and another to get the adjustment going in the right direction). Perhaps it is wise to write down left screw into and right screw outward (or the reverse) so you remember between trial runs which way you are turning things and can continue as necessary.

To maintain the perfect alignment we obtained last time, a check that can be done is to place a piece of tape on the front side of the tire tread of each tire and measure the distance between them. After turning the tie rod ends inward and outward, the distance should remain the same. Any variation means you either turned both sides inward or both outward, not correcting the alignment with the steering wheel. The tape method has to be replaced after each test drive too as it will come off as soon as the tires turn on the pavement.

Another trick I use when doing these adjustments is when raising the front end up to gain access to the steering parts, use wheel ramps rather than jack stands. Ramps keep the weight of the car on the tires and that tends to hold the wheel alignment in place. Jack stands leave the tire assembly hanging loose and you can go overboard quite as easily making alignment changes.

Also keep in mind that most roads have a center crown for drainage. This makes the center of the road slightly higher than the shoulder edge and this slope can cause the steering to pull toward the lower side. This pull makes it look like the steering wheel is not centered as you need to adjust the track slightly to the left to overcome this slope. So make sure the test road you use is flat enough to not give a false reading during your test drives or find a dual lane road and test drive on both the right and left lanes to see how the steering wheel sits when going straight ahead.

One last note is doing a wheel alignment and steering wheel centering is that the adjustments I suggest here are based on a good suspension system. The methods apply to all MGs from TDs on (only TCs dont have rack and pinion steering or similar tie rod assemblies.) Often many parts in this front end assembly get severely worn and getting the toe-in within 1/16 and centered with the steering wheel aligned is nearly impossible. I will go into how to check the suspension and steering systems on your MG for excessive wear in the next issue.

 

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