Sunday, April 09, 2006


Suspension replacement.
The day before i was going to change the shocks, i went round the car and sprayed a load of WD40 on the top mount nuts, and the lower strut nuts in the hope of loosening them up a little.

Ingredients:

Socket set
Spanner set
Pliers
21mm crank wrench (unless you have an impact wrench)
Spring compressor set (only £14)
WD40

Breaker bar to match your socket set/big piece of scaffold pipe/impact wrench (an impact wrench will take between 1-3 hours off the length of job!)
4lb club hammer (just in case/for fun)
digital camber tool (if you're flush)
Cotton thread and a nail (if you're not)


Rear suspension:

Loosen wheel nuts, carefully jack the car up, remove wheel.


Remove the bolt round the back of the bottom of the strut. Remove the parcelshelf, then pop the two plastic sidings from above the top nuts' location, these are on clips and come off with a fairly gentle thump from underneath. Remove the top cap, then get your wrench on the top nut and loosen it.

Push down on the disk/hub so as to free the bottom of the strut from its position. Keep hold of the bottom of the strut, remove the top nut completely, the strut will come away from its top mounting and you'll have to navigate it around the brake lines and out of the way of the brake disk. Put it on the floor!

Take the top mount off the strut unless its stuck in position in the top of the wheel arch. Put spring compressors on the spring and tighten until the spring moves around freely. Remove second inner top nut, then top cap, then flimsy plastic strut cover and bump stop bushing. Lift compressed spring off the strut. Take compressors off and apply them to new spring. put existing bumpstop on new damper if its in good shape, or use replacement, then flimsy cover, then put compressed spring on the new damper wide end first, making sure end of spring sitts snug against recess in the strut plate (its obvious when you're looking at it). Put top cap on and then tighten up inner top nut, this nut doesnt have to be on super tight (50lb/ft if you have a torque wrench). Remove compressors. Place top mount back on and lift strut back into position on car. Put top nut on loosely to hold it in place, then push down hub so as to navigate the bottom of the strut into its position. Put lower strut bolt in place and tighten. Lastly, tighten top nut (80lb/ft) nice and tight. Grab the strut and see if you can move it about, it should be solid. If it moves about you've done something wrong. If you've put shorter springs on the spring may move around a little in the strut, this is okay as you have no weight on it yet.

Put wheel back on, remove jack. Repeat on other side.

Well thats the quick bit done. The fronts are exactly the same only you have 2 extra bolts to do. Plus simple camber setup.

Front Suspension:
Before you jack the car up, loosen the top nuts, you might have to remove the top mount covers if you have them. These can seize up and its easier to loosen them while there's weight on the damper. The standard VW shox have a 7mm/size 7 Allen Key inner and a 21mm nut. So get a crank wrench on the top nut then place a 7mm Allen key in the hole above, and turn the spanner anti-clockwise and the key clockwise. It should make a nice cracking noise. Be careful to get the allen key right in the hole. If you havent got a crank spanner you could grind edges on a 21mm socket to get a spanner on it - the allen key will fit thru the top.


If the top nut is really on tight you'll have to use a bigger bar/pipe for leverage. Place a bit of hardwood against the bulkhead and move the key to rest against it, then gently & slowly apply pressure to the bar on the nut. If it still won't budge go buy an cordless impact wrench for £50. If you have an impact wrench with a 21mm socket you can throw the allen key away as it'll take the top nut off in about 2 secs flat.

Anyway, back to the job. Loosen wheel nuts, jack car up on the 5x15cm ridge about 20cm in from the side sill. Take wheel off. With a normal pair of pliers, unclip the thin steel spring clip from the strut, it will ping off and be held by the brake sensor wire, so let it hang there for now. Gently push brake hose from its mounting bracket (1) - use WD40 if its really stiff. Remove Brake sensor wire from its bracket (2) on the other side of the strut. Remove both lower strut bolts (3 & 4). Clean nuts with wd40 to remove any grit, then clean the camber bolt nuts - haha! While supporting the bottom of the strut, remove the top nut and top cup. Check again that the brake line and brake sensor wires are out of the way then carefully give the bottom of the strut a firm pull to free it from its upright hub mounting bracket. Don't let it hit the rubber drive shaft boot or the disk, or anything else. Navigate the strut out of the car.

Put spring compressors on the spring and tighten until the spring moves around freely. Remove second inner top nut, then top mount, top cap, then flimsy plastic strut cover and bump stop bushing. Lift compressed spring off the strut. Take compressors off and apply them to new spring. put existing bumpstop on new damper if its in good shape, or use replacement, then flimsy cover, then put compressed spring on the new damper wide end first, making sure end of spring sitts snug against recess in the strut plate (its obvious when you're looking at it). Put top cap on and top mount, then tighten up inner top nut, this nut doesnt have to be on super tight (50lb/ft). Remove compressors. Remove the little brake hose bracket from bottom of the strut, there's no nut, just a bolt (red arrow in pic below). Fit it to the new strut on the correct side. Remove the little plastic bracket from the other side that the brake sensor wire uses. Fit this to the other side of the new strut. If you don't have this plastic push-in bracket you could always use a small cable tie.
Lift strut back into position on car. Put top nut on loosely to hold it in place, then navigate the bottom of the strut into its position. Put both lower strut bolts in place and tighten loosely. Tighten top nut (80lb/ft) nice and tight.


Now for the camber adjustment. Basically for a decent setup you want 1deg of negative camber. Grab the disk/hub and move it around. Find the limits of its movement. Tie a nail to a piece of cotton (makeshift 'plumb-bob') and hold the cotton against the disk so that the nail hangs free. Move the hub around so that the cotton hangs away from the disk, then move the hub gently until the cotton just touches it all the way down. This should be 0 deg camber, keep moving the hub a tiny bit more ie. bottom of disk towards you about 5mm. This should be fairly close. Tighten up the 2 bolts making sure nothing moves while you do it. You can buy a camber gauge for £30 that has a magnetic end which you stick to the disk and it tells you exactly what camber you have. I keep meaning to buy one of these. Its important that you get the camber settings as close to exactly the same on each side.

Reconnect the brake hose into the bracket, push the brake sensor wire into the clip on the plastic bracket. Grab the strut and see if you can move it about, it should be solid. If it moves about you've done something wrong. If you've put shorter springs on the spring may move around a little in the strut, this is okay as you have no weight on it yet. Put wheel back on, remove jack. Repeat on other side. The car may not look as low as you thought or as low as the suspension kit said. Don't worry! it takes a while for the dampers to 'settle'. An hour or so of driving should be enough. But i would wait a couple of days just in case.

Camber adjustment part 2. Now the dampers have settled we can have another look at the camber. Make sure the wheels are straight. Hold the plumb-bob against the front and back of the tyre to check your camber. It should hang against the front face of the wheel/tyre, but hang away from the back of it if you've set it well already. Also, the nail on the plumb-bob should hang away from the back of the wheel (in the same position on the wheel) the same distance on each side. Hopefully this'll make more sense when you're actually doing it =)

If things are looking a miss, jack the car up, loosen the lower strut/camber bolts and adjust to suit. Then re-fit wheel and check again. This is pretty tedious, but worth it if you want a perfect handling setup. Once you're happy its about right, head off to the alignment centre and have the tracking done. Ask them to measure the camber too (most will do anyway). Tell them you've intentionally set it a little negative and he'll know you want to be able to corner nicely. Lastly and importantly set your tyre pressures properly, then drive it and laugh at what a difference its made !!

Here's some comparison shots.
Before...


and after a few weeks to settle...


And finally a couple front quarter shots to give an idea of the new stance...

3 Comments:

Anonymous centaurandrew said...

Found this guide extremely useful when changing the shocks on my mums mk 3. many thanks. However, just for futrure reference:

You positively cannot "grind edges" on a 21mm spanner on the strut tops, it just wont work!! If you don't have a crank spanner or air ratchet you need to use mole grips which is extremely tedious.

Many thanks for the great guide though.

9:45 AM  
Blogger Grego said...

Hi Andy, i meant grind the edges on a 21mm socket so you can get a spanner on it while having the allen key going thru the hole in the top !

Glad it was a helpful guide for you.

10:26 AM  
Anonymous centaurandrew said...

I see what you mean, I must have misread it!!!

7:30 PM  

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