I have a 1929 AD type chummy that is un-driveable at present because of steering wander. I drive a lot of vintage cars but have never experienced anything as bad as this. The top of the king pin is inclined forward and should clearly slant back by 5 degrees. I have jacked up the front axle and placed it on axle stands, placed a chock under rear wheels, slackened back the radius rods and slackened the front spring U bolts. I was hoping to be able to alter the castor by twisting the radius rods as per A7 companion, and placing a wedge between back of spring and chassis, but nothing is moving. I have just thought that maybe I should release the handbrake but I still cannot see how I can get the wedge under the spring without lifting out the engine. Am I trying to complicate a simple job or do I need to get expert help?
I am using a big adjustable spanner to try to twist the radius rods, but I am not Charles Atlas.

Location: Esher, Surrey U.K.

Seems an incredible error. The spring must be very twisted. Have the arms been interchanged?

The twisting is more a means of correction than adjustment. The arms tend to twist themselves from the intended vertical.

Would be very interested in your views cf other vintages when sorted.

Location: Auckland, NZ

Something seems to be manifestly wrong if the king pins are leaning forwards rather than rearwards. Is there any accident damage or has the axle beam been put on backwards relative to the hubs?

Location: Gard, France 30960

To ask a silly question, are the radius rods on the correct sides-they are handed.

Thanks for your answers. The rearward inclination is only slight, but just as noted in the A7 companion and in other posts on the forum, it has a marked effect on the handling of the car making it dangerous to drive. I am just trying to correct the castor angle in the way suggested in the A7 companion and need to know if I need to slack off or adjust anything else to be able to achieve this adjustment.

I have taken off the radiator to access the u bolts and have axle stands under the axle. The radius arms are loose but I have not taken off the nuts as the A7 companion says to tighten them up once I have twisted the radius arms to correct the castor.

There is also advice to put a wedge between the chassis and spring to prevent braking forces moving the radius arms and castor angle back. Again I would like to do this. I am hoping not to have to remove the axle, which does not look any different to other standard A7 axles I have seen. It certainly does not look bent, although the car has obviously had a hard life.

Location: Esher, Surrey U.K.

Roger following the excellent advice about "handedness" the bronze cups should come together roughly parallel and near the ball. The front axle must not be reversed relative to the hubs because the shocker bolts are on a taper.
More caster angle can be achieved if you flatten the rear springs. This has the added advantage of reducing rear axle steering, a cause of wander. Can we assume there is no play in the steering linkage and spring shackles?
What method are you using to get an accurate measure of the caster angle? cheers Russell

Location: oz

Hi Squeak, thanks for your message. I have not tried taking the ball joint apart yet to look at the ball cups. All I have done to check the king pin inclination is to compare mine with numerous other sevens, purely visually and it is obvious my king pins are slightly inclined in the wrong direction. There does not seem to be much play at the steering wheel, no more than other sevens I have examined. Wear in the shackles is not excessive either because the car has been regularly checked by British MoT examiners. As a keen cyclist, I am familiar with the effect that negative castor angle has on the handling of a bicycle and the seven seems to behave in the same way.

Taking off the rear springs and flattening them seems a rather expensive, time consuming and difficult way of correcting the castor angle when I am actually working on the front of the car, although I have no doubt that you are right.

Location: Esher, Surrey U.K.

As other have already suggested, I think it would be worth removing the radius arms and checking they have not been fitted incorrectly. The change in angle of the portion that goes through the axle beam eye is only slight (when the arm is level, that portion should point up slightly) It is discernible but you have to look for it. It wouldn't be the first time I had come across a car where they were the wrong way round. In fact, round at a pal's once, who was one of the best Austin 7 mechanics I knew, we were investigating the wandering characteristics of his car and discovered that, for years, he had two right handed radius arms fitted!

Location: cambs

You'll get a better idea if you put the axle stands under the chassis rather than the axle - the front suspension should be unloaded so you can see what's what.

Location: Gard, France 30960

Roger,
I had a similar problem with my 29 chummy. I could see what was wrong, the front chassis crossmember was bent but as it was my only means of transport, the easiest mod was to make a 3/8" packer between the triangular radius arm ball bracket and the front crossmember. This wasn't enough to correct the steering wander so I made 2 off 5/16" slotted washers fitted between the axle beam and the rad arms. After this it steered fine. These "temporary "mods stayed on the car from 1969 to 2000 when I took the car off the road for a major renovation. It must have done many thousands of miles in that period.
Hope this helps.
Dave.

Location: Sheffield

Thanks, Hugh. That is good advice. I will remove the radius arms and check them out. It will give me the opportunity to see how they fit and to clean them up if nothing else. I will report back. I learned to drive on a seven back in the 1970s. My Ruby DRF 65 steered very well, stopping was a different matter, but I ran it for about 3 years before changing to a Morris Cowley. I only recently acquired another seven that has been off the road for at least 10 years. After major work on the engine, it now runs but is un-controllable due to the steering wander.

Location: Esher, Surrey U.K.

Determining angles with protractors etc can be tedious. For small angles the inclination is about 1 in 60 for each degree. With a level and a few packing pieces can sort.

Of course the car must be level.
(Years ago whilst listening to a compelling program on the radio I fitted a towbar meticulously level to a car, but forgot it was jacked at one end!)

Location: Auckland, NZ

I have now removed the centre bolt from the radius arm balljoint expecting to be able to take it apart but nothing moves. Just how much strength do I need to get the radius arms off in order to check that they are the right way up?

At least I now have a nut and bolt to clean up. - Roger.

Location: Esher, Surrey U.K.

Location: North Yorkshire

Roger,

you can check if they are the correct ones for each side visually.

1A4024 - Offside

1A4025 - Nearside

Thanks Steve, I will wiggle them about a bit and see if I can get them off. - Roger.

Location: Esher, Surrey U.K.

Thanks for the pictures Ruairidh, now I will know absolutely whether they have been put on incorrectly. One side looks a little out of shape slightly and may need straightening or replacing. It will be a relief to get this problem sorted. Have checked the spring shackles, axle and kingpins and all seem to be sound. - Roger.

Location: Esher, Surrey U.K.

Along with the nut and bolt there should be a spring....

Simon

Location: On a hill in Wiltshire

I'd suggest lots of application of Plus Gas or equivalent and 'wiggling' them as advised. The temptation, of course, is to thwack them with an FBH on the end of the threaded portion, but in my experience, that never ends well..

Location: cambs

Whether or not the bolt clamping the bronze cups always had a spring has been raked over before. My RP seems to have never had a spring.
(At one stage, to ensure the cups were a secure fit, I set them in solder.)

Location: Auckland, NZ

No 'raking over' as you put it- the radius rod front ball joint doesn't get a bolt with spring until after 1933.
Spare Parts List 1218A for March 1935 lists on page 43 a new bolt and spring although the pictures on page 44 still show the old assembly and part numbers.

Many cars would have had the longer bolt and spring fitted in the intervening 80 years.

Tony.

Location: Malvern, Melbourne, Australia.

Thanks, Tony, that saves me looking for a spring when I get the joint apart. Looks like I might need to straighten one of the arms as I now see it is slightly bent. The cross member is fine though.

Location: Esher, Surrey U.K.

Hi Ruairidh, I was still having trouble getting the radius arms off so cleaned up the ends to reveal the numbers. They were correctly fitted, so I have decided to leave them on, re-fit the bolt and put a wedge under the axle to correct the castor.
Thanks for your advice which saved me some time and skinned knuckles. - Roger.

Location: Esher, Surrey U.K.

Roger,
My fear is that you just my be going around in ever decreasing circles!
No one so far has mentioned the spring shackles which, when under tension will look to be sound, but any wear in the bushes will have a huge detrimental effect, and just how exactly are you going to fit a tapered wedge under the spring with the engine in place, and for that matter what size and what material is it going to be? not to mention the ply packing between the spring and chassis. Why not "bite the bullet" and do it properly. Take out the engine and gearbox, drop the whole front end and start from scratch, that way you won't think its all right, you'l know it is. Yes it will take a day or two but it will be worth it in the end.
John R

Location: As far east in Kent as you can get

I think you will still need to twist the radius arm ends to get a caster change, as you mentioned initially.
Packing the spring mount won't change this.

Tony

Location: Malvern, Melbourne, Victoria, Australia.

Tony,
I have always had a problem about "Twisting the radius arms to increase caster"
Yes it does work but at what cost, by twisting the arms you are forcing the axle against the shackles which will accelerate wear in the bushes, is it not better in the long run to get the set up right first time?
J

Location: As far east in Kent as you can get

John,

You are right of course but in the short term setting the pins back a couple of degrees by rotating the arms will make a difference to steering and probably not cause too much problem with the shackles.

Tony.

Location: Malvern, Melbourne, Victoria, Australia.

I'm probably being extremely dim but I've never understood how twisting the radius rod affects the castor angle.
Does the twist slightly increase the effective length of the rod thus pushing the axle forward which then increases the caster angle behind?
I've often read the piece in the Austin Seven Companion but can't quite get my head around it.
Perhaps someone can describe what is taking place in a way I can see in my minds eye?

Thanks, Perplexed of Polegate, Steve V

Location: Polegate, East Sussex, United Kingdom

Hi John, That is a very sensible suggestion and it removes all the verifiables and they will have peace of mind.
Do it once and do it right

Location: Tinopai NZ

Stephen,

The two radius arms come from a point at the ball joint forward at an angle to the front axle where the ends are set at an angle to go through the two parallel holes in the axle.

The angle at the end means that when the radius arms are twisted anti clockwise on the offside and clockwise on the nearside, this causes the axle and therefore the top of the kingpin to tilt towards the rear.

Make sense?

Tony.

Location: Malvern, Melbourne, Victoria, Australia.

Tony,
I was just thinking about my days as an apprentice, I had a kindly teacher by the name of George who insisted that we "got it right" can you imagine the scenario;
"Sir iv'e got an idea, if I twist it a bit and then hit it with a big hammer it might sort it" His reply would undoubtedly have been;" Lad I want a word with you" I would then have found myself cleaning every machine, and the floor, with a toothbrush for a week! As Colin said "Do it once and do it right"
J

Location: As far east in Kent as you can get

Hey everyone, it's an Austin 7 not a Mercedes. I am looking for a quick and dirty fix without perfecting or completely restoring what is a fairly grotty chummy. I did the twist and it is looking much better. I have just also discovered that one of my spring shackles is in 2 pieces. I wonder if that was having an effect on the steering? - Roger.

Location: Esher, Surrey U.K.

Hi Tony,
Yes indeed!
Thanks very much.
Steve V.

Location: Polegate, East Sussex, United Kingdom

Sorry everyone, used the wrong word. It's the front spring U bolt that is snapped, not the shackle. Would have spotted a broken shackle much more easily. May recondition the shock absorber at the same time as sorting the U bolts. Hopefully the handling will be transformed. - Roger.

Location: Esher, Surrey U.K.

Should be transformed Roger.
Steve V.

Location: Polegate, East Sussex, United Kingdom