Front Suspension and Steering

By Walt Blanck

Originally published in the Austin-Healey Magazine, July and August 1976


Diagnosing the problem


The first thing to do after determining you have problem by experiencing vibration, erratic steering, loud noises or other incorrect front end action is to try to isolate the problem and set about to correct it. Probably the most common cause of front end problems is wheels and/or tires out of balance or untrue. There are several ways to check this:

  1. Jack up the front end so the wheels will spin free (remove hub knock off).

  2. Using a carpenter square, determine if wheel hub is parallel to floor (see drawing). Shim under the square at the floor (points A and B) until the upper part of the square is touching both top and bottom of the hub (C and D).

  3. Spin the wheel and tire.

  4. Hold a piece of blackboard chalk near the tire sidewall while it’s spinning. Keep moving the chalk closer until it makes a mark of the tire.

  5. Again, using the carpenter square you can determine the amount off true you wheel is by setting the chalk mark area at the square, rotating your wheel 180 degrees, measuring the distance between the wheel and the square. A distance of 1/16 to 1/8 inch may not be significant depending on the remainder of the diagnosis. A larger distance may require getting your wheels tuned professionally.


The next step would be getting the tires balanced. A bubble balance at most gas stations is generally satisfactory. Dynamic balancing (while the wheel is spinning) is the most accurate. Tires tend to get out of balance with use especially if other parts of the steering or suspension system have been damaged, this should be unnecessary. Once it has been determined that the wheels and tires are true and balanced, then a check should be made of the remainder of the steering and suspension system.


King Pins – Swivel System


To determine if there is excessive wear in the axle assembly; replace the knock off hub, grab the tire (while still jacked up) at the bottom and attempt to move the tire in and out. If there is no discernible movement, your king pin bushings appear to be OK. It has been my experience that only the lower bushing wears seriously. If there is any movement, the bushings should be replaced.


Wheel Bearings


To check for worn wheel bearings, grab the wheel at two points opposite each other on the outer diameter of the tire and attempt to move the wheel in and out. This is only a cursory check and final determination is to remove the wheel and bearings and carefully inspected scores, worn bearing cage or other signs of degradation. Shims are available to take up some bearing wear, but replacement is recommended.


Ball Joints


Worn ball joints can easily be detected by looking for movement of the ball joint within its housing (see picture and rock it on the ball. If it feels real loose and sloppy it is worn. If some resistance is felt to the movement, it is probably OK, although dirt and grease may be restricting the movement.


Steering Box and Idler


Play in the steering wheel (free movement of the steering wheel with not movement of the wheels) can generally be adjusted out. The workshop manual tells how to do this. Excess movement may be the result of worn ball bearings in the steering column or the need for shims at the lower end of the steering box. A worn idler can be detected by moving the pitman arm and getting excess movement of the shaft inside the idler body. Looseness in these components as well as in the ball joints may result in strange knocking noises when going over bumps, etc.


Sway Bar


The sway bar contributes considerable to stable handling and good road performance. If the rubber bushings are worn to the point where they no longer provide resistance to movement, or the end links are broken, or if the brackets are broken that fasten to the frame, swaying will result under most driving conditions.


Rebushing the Lower A-Frame Arms

Now that we have inspected and analyzed the front end systems, rebuilding or adjustment can begin to return the good handling characteristic that you Healey was born with.


The first step is, of course, to get the car up on jack stands and remove the front wheels.


The next step is to remove the tension of the front coil springs. This can be done several ways. The best way is with a spring compressor. However, if you don’t have one or can’t rent one an alternative method is available to you.


Compress the spring using a scissors jack under the lower spring plate (1). The weight of the car will help you. Raise this jack until the frame just rises off the jack stand. Then take several sturdy coat hangers and securely tie the coils together in this compressed state. Put the coat hanger through the uppermost exposed coil and retrieve it from the lowest exposed coil. Bring the coat hanger together making close bends around the coils, eliminating as much slack as possible. Make sure the coat hanger ends are twisted securely together. For added safety, you should go around the coils twice. Do this same operation on the opposite side of the coil so the coil is bound in at least two places. Remember, be sure it is securely fastened, since if the fastenings come loose, the result can be disastrous.


If you are sure the spring is securely tied start to release the scissors jack. The spring should be loose in its position. With the jack out of the way, start to remove the bolts in the lower spring plate. Remove the plate and remove the spring out of the bottom between the “A” arms. Store the springs in a safe out of the way place.


The next step is to remove the hub and brake assemblies and the brake backing plate from the swivel axle. This will allow the steering link to hang free. Be careful when removing the rake systems that brake fluid doesn’t splash on other parts since it is very corrosive.


You should now have the swivel axle free of all parts and are ready to remove it.


Loosen the upper trunnion (3) where the shock absorber arm fastens to the swivel axle and disconnect the shock from the axle.


Next remove the nuts from the cotters (4) locking the lower gudgeon pin (6) caps (5). Then remove the cotter (7) securing the gudgeon pin to the swivel axle. These cotters may be badly corroded and stuck in place. The cotters (4) are not to be removed but just relocated upwards. Before the nut is completely removed, tap gently upwards to loosen the cotter. This prevents end thread damage. If the cotter doesn’t release easily, soak with penetrating oil. The cotter(7) is to be removed completely and may require a drift to get it out.


Once the cotters (4) are loose, remove the caps (5) by turning with a wrench since they are threaded. Remove front and rear caps. Slightly tapping with a drift, push out the gudgeon pin (6) and the axle should now be free.


The lower “A” frames should be free of any attached parts and can now be removed. First pull the cotter pins at the nuts holding the “A” arms to the frame bracket and remove the nuts. Access to these nuts is limited and only small amounts of movement with a wrench are possible. The end of the trunnion with the nut is fitted with a machined washer (faced) d can be pried off and the rubber bushing (11) pulled out. At this point you may find that the trunnion is frozen to the metal core of the rubber bushing. Applied heat, penetrating oil and muscle are sometimes necessary to remove the trunnion. I have even had to cut the bolt with a torch to get it off, but you may be lucky.


Once you have all of it apart, you should clean all grease, dirt and rust from all of the parts and paint the exposed parts.


Assembly


All rubber parts when assembled should be well lubricated with rubber grease and all metal parts with a good grade of lithium grease. I wire brush (or replace) all bolts and lock washers. In a suspension or steering system, it doesn’t pay to take a chance with fatigued hardware. All fasteners are standard SAE (1/4-28, 5/16-24 and 3/8-24) and are available at all hardware stores. They are not metric. If possible, replace with plated bolts or nuts which will decrease future corrosion problems.


Needless to say the assembly is the reverse of taking it all apart. However, before completely assembling the swivel axle to the “A” arms and shock absorber, check lower king pin bushing wear. If the king pin feels sloppy in the lower end it would be well to rebush.


Part 2 from August 1976 issue


If your king pin bushings are worn, before reassembling, it would be well to replace them. Worn bushings would show a definite sloppy movement of the king pin (12) within the axle housing (13). Generally the upper king pin bushing (small end) is OK and does not need replacing. So we will only endeavor to replace the lower one. To disassemble the king pin from the axle housing, first remove the cotter pin from the nut at the upper end. Clamp the lower end of the king pin n a sturdy vise and remove the nut. You may need considerable persuasion since this nut receives no lubrication and could be corroded to the shaft.


Once it is loose turn it off until the nut is level with the top of the king pin thread. Reclamp the king pin in the vise to the king pin is free. Tap downward on the nut to free the king pin from the upper trunnion piece (14). The nut is kept in place to protect the threads while trying to free the assembly. The corrosion of the king pin to the upper trunnion piece may be so severe that an application of heat from a torch may be necessary. Once the king pin has been removed inspect it for grooves, bad scores etc., in the bushing areas.


Since the replacement bushing is undersize, an application of emery paper to any grooves or scores on the king pin will not damage it. Make sure any cleaning up of the king pin in this manner is done evenly around the shaft. While you’re working on the king pin, clean all grease passages with pipe cleaners and solvent. Now that the king pin is cleaned, remove the old bushing. A large drift or socket of the correct diameter will work fine for doing this.


Clamp the axle housing in a vise with the lower bushing (big one) facing up, and drive the bushing out. Putting the new bushing (15) in can be done by hand, but the use of an arbor press is recommended. If you choose to do it by hand, take a very fine file and chamfer on end of the bushing to serve as a lead. Lubricate the outside of the bushing with oil or light grease. Set the bushing in position and with a block of wood, gently drive the bushing down.


Take extreme care to assure the bushing remains perpendicular until it is in far enough to self align. Once the bushing is flush with the recessed surface, it can then be honed to fit. Although a machine shop will hone out the bushing with a step reamer, a brake cylinder hone will work if done slowly and carefully. Keeping the hone well lubricated and constantly moving in and out will remove the small increments of the bushing ID.


The king pin should be tested for fit periodically. Lubricate the king pin bearing surfaces. When the king pin will go in half way, then check it more frequently. Once it goes in all the way and fits snugly, the job is done. It would be wise to make the fit a fairly tight one even to the point of having to tap the king pin in the final half inch.


Initial wear in use will free this up. When assembling, replace the small cork dust seals with #210 O-rings (16). These can also be used on the gudgeon pin seal on the face where the axle housing and lower A-frame come together. Lubricate these O-rings liberally and they will far outlast the cork dust seals.


In the process of reassembling it is also wise to consider replacing the upper trunnion bushings (17) if the old ones are cracked and worn.


You will notice a tremendous difference in the steer ability and the overall handling of your Healey, if your bushings were badly worn.


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