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This last week, the RP has had a fair bit of use.
One odd thing that has happened twice now is that i have had to drive over pot holes as i brake onto a junction. This put the front of the car into a very odd wobble. Almost like the axle is oscellating on the spring shackles. This then sets the steering wheel wobbling also.
Ive studied all components carefully and can find no faults
Its a semi girling axle.
Does anyone have any ideas?
King pins are less than 1000mile from being done.
The steeringg box has bugger all play.
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The other possibility, as I experienced many years ago, is ball and cup springs in the drag link that had lost their strength. Worth a look...
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Location: Upton upon Seven
Car type: 1931 RN, 1933 RP
When i had my Singer Le Mans, that would go into violent "tank slapper" behaviour after travelling over a bump at slow speed. It was really scary. Turned out to be a loose shock absorber.
Roly
1931 RN, 1933 APD
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I had exactly this problem on my RN. I cured it by renewing the drag link ends, even though when I first checked them they seemed fine.
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Hedd, for what it is worth, the only time I have ever had wheels wobble on a Seven, it transpired the track rod steering arms were slightly loose in the axle. Long shot, but you never know.
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03-04-2018, 11:48 AM
(This post was last modified: 03-04-2018, 11:51 AM by Ray White.)
"One odd thing that has happened twice now is that i have had to drive over pot holes as i brake onto a junction. This put the front of the car into a very odd wobble. Almost like the axle is oscellating on the spring shackles. This then sets the steering wheel wobbling also.
Ive studied all components carefully and can find no faults"
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Assuming the radius arm ball joint is tight and you have no other obvious faults I think it is possible the the axle oscillation you suspect could be the cause. Axle "shimmy" is no stranger to many older cars and is often accompanied by "wander". In the case of the Austin Seven this is one of it's less endearing design "features".
The front axle and transverse leaf spring with shackles at either end has vertical links. The inherent flaw in this design is that the axle is not securely located and is free to move laterally in relation to the chassis. I am possibly in the minority of owners who have chosen to disable one of the shock absorber vertical links and utilise the arm to locate the axle. The redundant link is simply tucked up behind the arm out of sight.
The light weight and narrow track of the Austin 7 combined with 19" wheels and 3.5" tyres combine to allow the remaining front shock absorber arm to be sufficient. I am not saying this is the right thing to do - just that it works for me, as it has for others. No more wander or shimmy.
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Location: Salop
Car type: '28 GE Cup. '28 AD Chummy '30 RL Saloon. '34 RP Saloon. Too Many toys!
Father did the king pins on this car, perhaps 2 years ago, and had the axle off to do it. The car has probably done less than 1000 miles since.
Jacking up the axle and levering etc shows the king pins certainly are A1.
I shall investigate the connection from the axle to the chassis ball joint further, in the knowledge that there is a spring involved and father will have had it apart. This sounds the most likely problem. Perhaps the spring has gone weak.
Same goes with the drag link.
The car is presently hemmed in by furniture having had a carpet fitted yesterday. Investigation shall have to wait. Thanks for the suggestions.
I'm happy that the frequency of the oscillation is far from normal Austin wander. I've ridden in this car since I was 3, been driving it since I was 15 or so. I've never experienced this in this car (or any others).
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Location: Deepest Frogland 30960
Car type: 1933 RP Standard Saloon
Difficult to see on an RP without removing the radiator but a check on the tightness of the front spring U bolts won't go amiss.
