Rear Steer???

[classic2cv]

At speed the steering on my Tzd feels a little nervous

If it’s left to it’s own devices it will wonder and have to constantly correct it

Is down to the rear swing arms moving around due to worn bearings ?

It seems that sometimes it’s steering all by itself

[AndersDK]

If you have worn rear arm bearings you also have unwanted steering.
How much tendency to wander in steering depends on how bad the rear arm bearings are.
If the rear wheels are leaning to such an extent you get the tyre scraping against the wheelarch - it will be pretty bad.

If no appearant wear on the rear arms - you may have other problems in the front suspension components.

A potiential fatal problem may be the flexible coupling (hardy disc) between steering axle and rack pinion gear. Thats always the first check on steering problems, because its pretty well hidden and thus easy to overlook and forget.

2.nd call is the tierod/trackrod outer joints. They do however last for ages on a BX, not a common problem. Inner joints may fail too, especially on earlier cars. These too however also have a surprising long service life before they show up as problems.
3.rd call is the lower sviwel joints.
4.th call is the lower control arm rubber bushes.

Finally the front toe may be out. Must be within 0-3deg toe-OUT to get a stable steering.

[Doz]

Front toe makes a world of difference , especially on the narrower 165 tyres.

[classic2cv]

the front toe may be out. Must be within 0-3deg toe-OUT to get a stable steering.

come to think of it you might be right on that one

i'll have to check it out soon

on very smooth roads it does very well but on roads with grooves in them it does get to be hard work keeping it in a strighte line sometimes

it trys to dart one way then the other way

maybe the wheels are towing in a a bit and as Doz it makes a world of difference , especially on the narrower 165 tyres.

just the size i have