Dax De Dion Front Suspension Set-up

[MickyB]

Hi all

Getting to the end of my build and have decided it is time to tackle the highly technical area (to me) of setting up the front wheels/suspension.

This is the procedure I plan to take, if anybody can point out any problems or improvements with the procedure I would be grateful.

1. Front spings are wound right down at present and this seems to be about the 5.5inch ride height dax suggest.

2. Jack car up. Set up cross links so that they are at 90 degrees as per dax manual. (Does car have to be jacked up evenly on both sides to do this?)

3. Take off jacks and make sure car sitting on level surface.

4. Make sure both steering rack arms are adjusted to same length and wheels pointing roughly in same direction i.e forward.

5. Adjust camber by using spirit level and two nuts taped to rim of wheel. Adjust camber on top ball joint so that there is a 2mm gap at the top nut on the rim. I assume I have to take wheels off to adjust this, is this correct?

5. Adjust toe by using a large c frame as described in Dax manual so that it hits the outside wall of each tyre. Adjust steering rack arms so that there is a gap on the front rim edge of 0 to 20 degrees. Does this equate to a measurement in mm does anyone know?

5 . Recheck and readjust as required.

Just a general question when Dax Say that toe in and camber on the front is 0 to 20 degrees, does this mean that you can have any setting you like in this range, as long as they are the same measurement each side?

Many thanks
Mike

[JonnyT]

Hi Micky,

First of all it was very fiddly (I am sure Dave B will tell me that I spent too much time trying to get it absolutely correct later on in this post!!).

Secondly read Andy's website on setting up the front suspension - he really knows what he is doing on these things and explains it very well - http://users.telenet.be/cobra427/

But some points from when we did it, in response to yours:

2. I think you have to use the set up bars to set the suspension cross links - two pieces of metal with 304mm centre to centre is what you need. This then holds the suspension at exactly the same position that it was designed for which is what you need. Having tried other methods I was told by Peter that this was essential.

In regard to the cross links you may find that you do not have quite enough adjustment to get them perfectly upright. The reason for this when we did it was because the rod ends were bottoming out on the end of the thread in the cross link. Take the rod ends off and shorten slightly - I had to remove about 1/4" but given the length of the thread I doubt a little more would hurt.

Then set at 90 degrees as indicated.

From memory we then set the alignment of the front wheels. This is done by adjusting the length of the steering arms. There was a reason for this that Peter gave but I can't remember what it was. Remember that you can obtain less than a full turn on each steering arms because the arms rotate in the steering rack itself.

Do remember that the measurements are degree minutes rather than degrees.

THe only other comment I would make is that when setting the tracking it is better to set it using the rim of the wheel rather than the tyre wall because of the variations in diameter etc.

Hope this helps,

Jon

[dave]

Jonny.
YOU DA MAN!
The 304mm bars are the key to making this job a breeze. Anything else (With the wheels on) will be a very long winded job.
This whole job is best done when the car is at rolling chassis stage and on stands (And level) without the body fitted and can be set up easily in under an hour (Jonny, notice I didn't say 15 minutes there!)

Micky.
I think you'll find the tracking setting to be more like 0-20 minutes not degrees.

[JonnyT]

'(Jonny, notice I didn't say 15 minutes there!)'

That would have been reassuring if it hadn't taken us about 2 days!!!!

Still its great fun learning (although I am sure that Peter is going to refuse to answer the phone to me one of these days, and everbody here is going to get bored with my inane questions!!)

[Wayne]

Hi Micky

I'm just finishing the rolling chassis on my beloved vehicle. Having read your mail, is it easier to set up the suspension at this stage rather than later, as per the manual?

Wayne

[JonnyT]

See Dave's post for his view. Personally I think it would be much more difficult with the body on - there is so much more space without. Using the set up bars it is also possible to get it set up perfectly so I can't see a reason not to.