03-12-2024, 08:38 PM
Back to the start of this thread. Alarming steering thrashing left right left right, shimmy with avengeance at about 18 mph, starting with a bit of wavy tarmac. It thrashed the steering wheel about and the only thing was to slow down to a stop, or maybe 2 mph.
Again a huge thanks to everyone on here for advice and also thanks to Ruaridh for advice too.
It now seems to be fixed, though time will tell!
Various things were suggested as a cause but in total I think seven people suggested it was all to do with the steering drag link, free play, and the little coil springs inside each end.
I checked everything for free-play and could only find a tiny bit of sideways movement in the king-pin top bushes, and a fair bit of play in the steering box.
After the mentions of the drag link end I tried them again and yes there was a tiny bit of play in the front joint of the drag link.
My first experiment was to see if it would still shimmy, at that time it had only done it twice, on the same evening. So without fixing anything I drove it in town at about 20 mph and aimed for every bit of undulating road repair. It did the shimmy. I went round the block and yes, I could make it shimmy whenever I wanted.
Next was to adjust out most of the little bit of play using shims with no spring fitted (maybe I should have driven it like this, but didn't) I then fitted a new spring inside the front joint. A test drive did not create shimmy. Three times over the same wavy tarmac and no shimmy.
As yet I have done nothing with the back end of the drag link, it still has a tiny bit of play, and a very old spring.
New and old springs were very different. Old were shorter and weaker.
Just how such a small amount of play and weak spring can allow this alarming shimmy, we don't know, but for now I'm back to enjoying it.
Thanks again for advice, thanks to Jamie for selling the springs, and thanks to David Cockrane and Ilke for bothering to stock exactly the right bolts that go through the drag link.
Again a huge thanks to everyone on here for advice and also thanks to Ruaridh for advice too.
It now seems to be fixed, though time will tell!
Various things were suggested as a cause but in total I think seven people suggested it was all to do with the steering drag link, free play, and the little coil springs inside each end.
I checked everything for free-play and could only find a tiny bit of sideways movement in the king-pin top bushes, and a fair bit of play in the steering box.
After the mentions of the drag link end I tried them again and yes there was a tiny bit of play in the front joint of the drag link.
My first experiment was to see if it would still shimmy, at that time it had only done it twice, on the same evening. So without fixing anything I drove it in town at about 20 mph and aimed for every bit of undulating road repair. It did the shimmy. I went round the block and yes, I could make it shimmy whenever I wanted.
Next was to adjust out most of the little bit of play using shims with no spring fitted (maybe I should have driven it like this, but didn't) I then fitted a new spring inside the front joint. A test drive did not create shimmy. Three times over the same wavy tarmac and no shimmy.
As yet I have done nothing with the back end of the drag link, it still has a tiny bit of play, and a very old spring.
New and old springs were very different. Old were shorter and weaker.
Just how such a small amount of play and weak spring can allow this alarming shimmy, we don't know, but for now I'm back to enjoying it.
Thanks again for advice, thanks to Jamie for selling the springs, and thanks to David Cockrane and Ilke for bothering to stock exactly the right bolts that go through the drag link.