Thread: Making EAS Height calibration blocks

I know what you mean by simple, but wouldn't it be just as easy to cut up some 30mm heavy duty Perspex rod ?

I guess you found my diagrams. They are designed to be used with T4 aka Testbook.

I can't see why you couldn't use timber blocks.

See RANGE ROVER P38A SUSPENSION SET UP AND CALIBRATION (English Version)

Short answer: Yes
Medium answer: Yes with some changes

Rather than use 4x2, I used a 1.8m length of 28.5mm diameter (finished size) dowel ...Tasmanian oak from the local hardware store. I examined it carefully for splits (there were none).

I cut the dowel into the following lengths, based on the calibration numbers in the LR EAS Systems Information Document ...the slightly longer lengths for each set are the rear axle -bump stop distances)

2 x 145mm
2 x 140mm

2 x 105mm
2 x 100mm

2 x 80mm
2 x 75mm

2 x 40mm
2 x 35mm

The 28.5 mm diameter is a neat fit through the hole in the bump stop.

I didn't make a hollow in one end of each "rod" to accommodate the end of the bump stop.

I had some early concerns about the ability of the rods to take the weight of the vehicle, however I used the following calculations and there is a reasonable safety margin...(of approx. x2 min)

The compression point of Tasmanian Oak is listed as 60Mpa or 611.8 kg/sq cm.

A 28.5mm diameter dowel has an end surface are of 6.3 sq cm

Max. weight scenario:

Say the vehicle weighs around 2400kg (full fuel, bull bar + a load of 'stuff' on board), this equates to 600kg per corner.

The dowel block at each corner is experiencing a load of 600kg/6.3 sq cm or 95.2 kg/sq cm which is a safety margin of approx. 6.4 (i.e. 611.8kg/95.2) assuming the weight of the vehicle is evenly spread across the end of each dowel.

It is not.

The weight of the vehicle is being transmitted through the tip of the bump stop stud, which is significantly less than the 6.3 sq cm. area of the dowel

So, say the tip of the bump stop is 2 sq cm, then the total weight acting as a force on each dowel is 600kg/2 sq cm = 300kg/sq cm which is about half the theoretical collapse point of the dowel.
That is for a well loaded vehicle.
Obviously if the vehicle is closer to standard "kerb weight" which is about 2200kg or less then the safety margin improves.

What I did was to set the highest dowels in place first, take the 'bit' readings as the reference points, jack the vehicle a little at each corner and substitute the next set and gently lower the jack so that the bump stop did not "crash" onto the dowels..

sorry for the long post

Originally Posted by daf11e

I know what you mean by simple, but wouldn't it be just as easy to cut up some 30mm heavy duty Perspex rod ?

Nylon rod seems to be the preferred choice, I'm not sure if Perspex rod would have the same compression strength as nylon..

Agreed hoges, my thoughts were something of that type of material cut to size would not be difficult and fit into the bumpstops

Can't you guys just run around with a tape measure? Works well for my classic eas.

I tried the blocks, using an assortment of 6mm, 12mm thick plywood & other thickness blocks of 2"x 2" to get the gaps required. But ended up sacking it. Using a tape measure on the wheel arches gets comparable results.

The key is to use a manual inflation (EAS bypass) set up & a workshop compressor to achieve the heights you require. Then obtain the height readings and write them to memory. Time consuming, but worth the effort.

Originally Posted by davidsonsm

Using a tape measure on the wheel arches gets comparable results.

If using that method, measure from the arch to the centre of the wheel, not to the ground.