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Them Bones Them Bones Them Wishbones - Chris Laycock
 

FITTING TUBULAR WISHBONES

Having now put the five-speed gearbox conversion on the backburner for the time being, I now wanted a winter project for the good old Locust. Something to get me out into the garage on a cold winter night and up to my armpits in engine oil a grease.



Casting my mind back to July 2003, on a "run" out with the Club, into the Heart of the Kent countryside to visit the "Darling Buds of May" car show,prompted a new project that would fit the bill.

After leaving the above car show, we had cause to visit a lovely county Pub ( as you do ) and have a beer. ( only one, drinking & driving ) Yours truly got stuck on the exit out of the car park with the front cross member scraping on kerbstones between the car park and the road. After backing off a couple of times, I managed to get the Locust back on to the main road. Now I have always had a very low front cross member. (I will wait for the laughter to subside) The front suspension on my chassis, which is the White Rose vintage from around 1996, has the Cortina set-up. As the car has been on the road for some 3-4 years, the front suspension has "settled", leaving the Front cross member about 2" clearance off the ground. The only way to increase the ride height was to put spacers under the coil springs or longer springs in order to push the front up, but this is a hit and miss affaire.
The other problem with the Cortina set-up is you cannot alter the caster or camber angles which leads me on to another annoying problem. From day one, whenever the steering wheel was turned, either left or right, the steering wheel would not self-centre. I could take my hands off the steering wheel and the car would continue in the same direction.. The Locust, I hasten to add, in this situation, was not dangerous. It was more like very neutral oversteer. which talking with other Club members, also seem to have a similar problem. The cause is, lack of caster angle, which on my car is actually 0 degs, when it should be about 5 deg plus. Anyway on with the winter project.
To remain within the limits of travel of the top & bottom ball joints, be aware that there are two different types of Locust chassis and the distance between the top & bottom wishbone pivot points will vary between the two types. The chassis which White Rose manufactured has the suspension "towers" fabricated from sheet steel. Measure the distance between top and bottom wishbone pivot points and you should have a measurement of 216mm. Mount your top wishbone as Fig 1.

 

Pre White Rose chassis has the suspension "towers" made from box section, like the chassis rails. Measurement for this should be 260mm and mount the top wishbone as in Fig 2.

Jack up car, take off wheels, brake calliper, and all the old Cortina wishbone components.

 New Wishbones arrived, complete with brackets and after stripping off the paint, I took them off to be Power Coated in Black.

 
 

8 Ford new bushes from a Cortina Part No. 6009975 were pressed into the newly painted top & bottom wishbones, using a large vice and large 32mm sockets.

The large angled flange bracket which held the tie-rod was cut off using an Angle grinder, as this was not required and so was the rear bracket from the old front tie rod bracket.

 

Two Top Ball joints from Ford Transit van & Two Lower Ball joints from Ford Cortina are required, with the angle flange cut off the lower ball joints, which are then bolted from the underside of the bottom wishbone.

Now, being a complete dork at welding, I called upon the services of a mobile welder to fix the new Front and rear Brackets, loosely assembling them into position using new bolts.

 

After a couple of coats of paint on the new brackets to was time to measured the length required from the top and bottom mounting points in order to establish the "stroke" of the shock when opened and closed.

1. Chock up the front of the chassis to achieve the required ground clearance, using 4" x 2" wood complete with hubs, steering rack and wheels. I was aiming for 4" ground clearance under the front cross member.

2. Keep the wishbones in the same place by inserting wood blocks and then remove road wheels.



3. Measure the distance between the top and bottom shock absorber mountings. This will be your mid point as the shock compresses. Mine was 29mm. Lift the Hub & wishbone assembly to check the point where either track rod ends or upper & lower ball joints starts to reach the end of its travel. Lower the assembly at least 15mm and again measure the distance between the mounting points. This will be the "closed" length of the coil over.



4. Lower the hub & Wishbone assembly back to its blocks.



5. Remove the blocks from under the Wishbone assembly and lower the Hub/Wishbones assembly to the end of there travel where the ball joints, upper & lower start to bind. This is now the "open" length of the coil over.



6. With these measurements, you should be able to lift the assembly by about 15mm and measure between the mounting points in order to find the correct Shock Absorbers length to buy. You should find that the "stroke" of your coil over will let the wheels move up & down approx. 3-4" and that I am told is OK for car of our type.

Don't BUY THE SPRINGS YET. Just get the shocks. The Shock Absorbers that I went for were the SPAX G2034 1.9" Adjustable RSX damper, which comes off of all things, a Mini!!!!!!! A lovely pair of Yellow Shocks turn up, and after fitting then on it was obvious that they would foul the old support ring on the Shock tower.Out with the grinder.

 

 Next to buy was the 1.9" springs. What is the correct spring rate when fitting coil over suspension. There is NO exact answer to this. It will depend on several factors. I understand that when WRV first started selling the wishbones, they advised the use of 150 lbs springs and updated to 180 lbs. I went for 150 lbs as the springs can be stiffened up using the adjustment spring pan rings.

 

So before you rush out and buy new springs, you will need to work out the "Effective Spring Rate". This will depend on what angle your Coil Over's are mounted at.

When I mount my Shock's, I put mine back into the original top holes making the Shocks nearly upright.

My coils over are mounted at 20 degs, which if I was aiming for a Spring poundage of 150 lbs, I had to fit Springs rated @ 170 lbs to aim for an effective spring rate of 150 lbs. Take a look at the Chart if your brain has gone into overload.

Spring Angle 10 Deg

15 Deg

20 Deg

25 Deg

30 Deg

35 Deg

40 Deg

45 Deg

Effective rate 0.96

0.93

0.88

0.82

0.75

0.66

0.59

0.50

 


 You can see from the chart that if your Coil over is at 45 deg, your 150 lb string is only 50% effective, in other words it is only about 75 lbs.

I wanted 150 lbs effective.>150 divided by 0.88 ( my 20 deg angle ) equals 170 lbs spring.

What I wanted next was the spring length.

 



1. Bolt the Shock and wishbone up, complete with hubs, steering rack and wheels yet again.

 


2. Chock up the front cross member of the chassis to achieve the required ground clearance. I was aiming for 4"

 


3. Wind down the adjustable rings on the shock, as far as possible and measure the distance from the rings to the top mounting face.

 

Mine was 6". I then order up Two 6" long x 170 lb springs, and when they arrived, it was a simple case of re-assemble on to the shocks. With the suspension all assembled and the car now on level ground it was to adjust the tracking to approx. 0 deg (I will take the car into a tyre centre to get it checked more precisely) and to adjust the camber angle. The castor setting was determined by inserting spacer washers on the lower bracket which has give about 5 deg + .



The ride high under the front cross member was now a tad under 4" after winding up the shock absorber spring adjustment rings to about half way up the threaded part of the shock. The camber angle was now set at 0 deg and the "toe-in" at 0.05 deg by using a tape measure,( this was checked a couple of weeks later by a Tyre company to be actually 9 deg of "toe-out". So much for using a tape measure. The camber angle was spot-on.) and after checking all the nuts and bolts have been tightened up, new split pins installed through the Castle nuts.

 

So out for a test run, and as it was in middle of February ( and YES the car is Taxed, MOT ed and Insured) so it was only a quick trip round the block to see how it would respond. A quick test on the brakes, and the car pulled up in a straight line. So far so good. Up to the T junction and a left turn, and immediately I could feel the steering wheel trying to straighten up. Not strongly, but just like a normal car should be. Next test was a few bumps to test the suspension. It felt a little stiffer than with the old set-up but apart from that, all felt good. The best part, was driving the car back into the garage, as a 1" high lip in the concrete had always "grounded" the car halfway down the chassis. The only way to get the Locust in, was to lay down scaffold planks and drive into the garage on them. No problems with the new set-up. Was it all worth it in money terms. Well, here's the costing

   

Top and bottom Whishbones   £110
Power Coating   £25
Mobile Welder   £25
Nuts, Bolts, & Washers   £15
Bushes   £32
Top Ball joints   £15
Lower Ball joints   £24
Spax AVO adjustable shocks   £170
Springs   £65
Spax AVO adjustable shocks   £170
Total   £481

A lot of money, but the car handles better, look's better, the suspension is more "tweakable", steering wheel self centres, goes in garage and better still, not likely to "lose" the sump when going in Pub car parks!!!!!!!!!!



Happy Locusting............ Chris Laycock.

Many thanks to Phil Manship for his very useful information, both written and verbal on the above project.

 

 

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