Matra Enthusiasts Club UK
FAQ's: Frequently Asked Questions
- My car wanders and needs constant correction to keep it running straight. What should I look for?
There are two likely possible causes here.
(1) Either the front steering is 'sticking' owing to seizing lower ball joints, or is very sloppy owing to worn and loose track rod end ball joints; or
(2) the rear suspension arms are moving causing rear end steering.
Taking the rear first, check the semi-trailing arm bolts are really tight. If these are loose the trailing arms will move around enough to cause unpredictable rear end steering. If the bolts have been tightened and appear to come loose again, or if you find them loose, check in case these bolts have been replaced with stainless steel ones. Stainless steel bolts are not strong enough and will stretch at the torques required on these mounting bolts. You need 8.9 hardness minimum. Similarly check the condition of the semi-trailing arm mounting bushes since worn ones will cause similar rear end steering.
On the front suspension, first check all ball joints, column universal joints and steering rack. Check the condition of the rubber gaiters on the bottom ball joints carefully. If there is any splits or damage to these gaiters, they will allow water in, which will eventually cause wear or seizing of the joints. It is the seizing that is harder to detect since often there won't be any excess play or movement initially. But this seizing up of even one side of the suspension will mean it cannot self-steer correctly which is what normally allows the car to run straight. You will find that as it runs slightly to the left or right, your 'slight' steering correction will actually make the car steer slightly the opposite way as the partially seized joint moves in 'steps' which are too big and these jumps mean it moves too far the opposite way! To change these lower joints you will need a special socket with four pegs to locate it in the joint to unscrew it from the upright. This joint is the larger of two similar joints that were fitted to this front suspension on various Simca/Talbot models. One was 45mm and the other 48mm. The Murena (and some late Solara) used the 48mm one. The special tool for this joint is the larger of the two sockets in a Sealey kit number SX0271.
These lower ball joints can be extremely tight and seized in with corrosion so even with the right tool it may not be possible to remove it whilst the upright is still on the car, as it is not rigid enough. Therefore you will probably have to remove it to a bench where it can be held firmly in a large vice. If you don't have the special socket, then you definitely need to do this. One of the notches that the pegs of the socket engage in, will have a locking tab bent in to 'lock' the ball joint in place on the upright. First bend that outwards to 'release' the ball joint, and then you might be able to simply place a large punch into one of the notches so as to rotate the joint anti-clockwise and give that a hefty smack with a lump hammer and the shock may start the joint moving. If you have special socket, you place that over the swivel pin and engage the pegs in the ball joint notches then put the swivel pin nut back on and tighten it up. This will lock the special socket securely to the ball joint. Now you can put a large socket on the hexagon of the special socket and using a long breaker bar for leverage, undo the joint. Once the worn/seized one is out, clean everything, fit the new one and secure it, and then refit the upright to the car.
To be finished...
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This was last updated 21st October '16