DIY: E36 Old Struts to Bilstein Sport Struts

[kyleabaker]

Please do this at your own risk. I am not responsible if you break anything. End legal mumbo jumbo.

Okay, to begin, this was performed on a 1993 318is, two doors, E36 with a Motorsport suspension from the factory, M42, automatic tranny, black on black, build date 01/1993. Your car may differ from mine. If it does, figure it out.

This DIY was also only performed with Bilstein Sport Struts, using the springs that are in place. Other Bilstein models may be different, and if you want to change the springs, simply switch them out when you assemble the new strut and spring.

Okay, on with the DIY!!!

You are going to need spring compressors for this job. I rented mine from AutoZone for a deposit of $40. They have safety locks on them, which made me feel much better about doing this for the first time.

First off, jack up the front of the car. Put the car on jack stands. Remove the wheels. Open the hood.

In the engine bay, find the strut tower. It looks like the picture below. In the pic, the 13mm nuts are marked with red and the strut bearing/ top bolt is marked in blue.



The top bolt is covered by a cap. Remove it like so:



Before you attack the top, loosen (don't remove) the lower mounting bolts. They are 18mm, if stock. You also may want to remove the brake sensors/lines from their place. Here is the location of the three lower bolts and brake lines:


Here is an up close view (from behind, obviously) of the lower bolts.



Here is an up close view of the brake sensors/line.



Before you unbolt the top three nuts, jack up the front control arm. Raise it a bit. Then take off the top three nuts. They are 13mm.

Once you unbolt the top nuts from the strut tower, lower the jack and remove the lower mounting bolts that you loosened before. It will probably be stuck on there. I whacked it with a big hammer to knock it loose and then pried the mounting points apart with a screwdriver. Now, the strut assembly is quite heavy. You need to maneuver it through and around the brake lines and sensors. They are wrapped around the strut. Great. I found that the best way to wiggle it out is to move the top of the strut towards the front of the car.

Now, at the same time, the brake rotor assembly is going to fall out almost into your lap. This is when it is good to have friends (strong friends, in my case). I strung it up with some bungee cords before even taking the strut assembly out. Like this:



Now that you have the strut assembly out, here comes the fun part. You have to disassemble the top bolt from the strut bearing from the spring from the strut. Yay!

Here's where the spring compressors come in. Tighten those down on opposite sides of the springs.



This is about the time when I put it in a bench mounted clamp.





Btw, here's a top view of the strut when it is out.



When it is in the clamp, to remove the top bolt, grab a breaker bar and a ViseGrip. Hold the strut shaft with the ViseGrip and break it with the breaker bar. Now, if you don't have the springs compressed enough, the top and bottom half-coil will explode a bit. No worries, it won't shoot that far.



Now that it's apart, I took the time to clean everything before I reassembled. To reassembled it, here's a couple of diagrams.
Real OEM:



My awesome version, which, after the lower gasket thing comes the strut.



Once you put everything on the strut in the right order, you need to tighten the top bolt on before you can move on. Here's the trick. Pull the dust boot up from the bottom:



And grip the strut shaft with a pipe wrench.



EDIT:
Dudesky writes:

FIY, this is a bad idea. If you marr the surface of that strut shaft, it will in time destroy the seal on the strut housing, blowing the shock. That's the reason for the dustboot; even particles of dirt can damage that seal. At the very least, put a rag between the pipe wrench's teeth and the shaft, or tape up the teeth. There's a hex socket at the top of the strut shaft:

The correct way to do this is to hold the shaft with a hex key while tightening the nylock nut. There's a specialized socket you can buy that allows the hex key to pass through, and it has a provision to tighten the socket with an adjustable wrench instead of a ratchet. Some people use an air ratchet instead; the ratchet tightens the nut faster than the shaft can spin.

Thank you Dudesky, however, my shafts are unmarred.

Get a breaker bar on the top bolt, grip the strut shaft and turn away. this way you can actually tighten the top bolt down (Bilstein provides a locking top bolt, which turns the strut shaft if not held in place).
Like this:



Take off the spring compressors (after the top bolt is TIGHT) and

TA-DA!!!



Assemble back into the car. Jack up the control arm and slide the strut into place. Hand tighten the top nuts (not to much, you need play) and hand tighten the lower mounting bolts, being sure to put LocTite 270 or better on them. Tighten the top nuts and then tighten the lower mounting bolts. Take off the bungee cord "brake-holding system".

Put the wheels back on, lower the car.
Tighten everything again once it is back on the ground.
Have your alignment checked.

Enjoy your new Bilstein Sports!!!

Source: http://www.unitedbimmer.com/forums/bmw- ... truts.html