cyclopticgaze

bmw 2002

Front Suspension Teardown

Dec 13, 2007

     I've been slowly working on a front suspension rehab.  I was going to do one epic post about the teardown, rehab, and buildup of the it all, but it's taking so long that I'm going to post just the teardown now.  At this rate, I'll post about the rebuild in a year or two.


     This started because I needed to replace the ball joints up front.  But it was obvious that the rubber bushings up front needed replacement, too.  And while it's all apart, let's upgrade the swaybar.  One thing snowballed into another and now the whole front end is in pieces.


     Both ball joints are completely worn.  The rubber is cracked and broken.  I know that they are original to the car because they are riveted to the control arm.  When the ball joints get replaced, those rivets have to be drilled out and replaced with bolts.  No bolts here means they're 37 years old.  Definitely in need of replacement.  The last thing I want is one of the wheels to literally fall off the car while driving.


     Job number one was to remove the front swaybar.  This was quite easy.  Swaybars are only under stress when the car is cornering, so removing the bolts was a breeze.  One of them was even broken already, making my job easier.  Normally, that would make me angry, but I have a shiny new swaybar from Ireland Engineering (with new hardware) waiting to be installed.  I'll dedicate a whole post to that.


The front suspension, viewed from the front of the car with the swaybar still attached.  The tension rod is coming towards the camera, leaving the picture on the left.  Above it, the front swaybar is coming towards the camera.  Both connect to the control arm, which pivots with the car at an in-board point off to the left.  Running straight up and down is the strut, attaching to the control arm at the ball joint.  The disk-shaped structure on the right is the brake rotor's dust cover.

front suspension pre-teardown


     With the swaybar off, the first order of business is to remove the tension rod.  The tension rod is under very little stress, and attaches to the subframe up front with only a single bolt.  Only one bolt attaches it to the control arm, also.  Neither of mine were difficult to remove.


Both the swaybar and tension rod have been removed from the control arm.  The ball joint here is totally shot.  The rubber's shredded wide open.  Dangerous.  The rubber bushing (hole facing the camera) is showing its age, also.  Notice the bolts connected by wires.  Those bolts connect the pitman arm to the strut.  The wire is "safety wire" that prevents the bolts from backing off and dropping the suspension off the car.  The ball joint itself is connected to the control arm by three rivets, covered in grime here (just below the shredded rubber).

worn ball joint


This is the in-board pivot of the control arm, removed of course.  This picture represents about a half-can of penetrating oil, lots of blow-torch heat, pulling, tugging, banging, and countless curses.  Over many weeks.  There's no rust, but dirty bolts that haven't budged their whole lives don't like to come off.  I pulled this off to clean up the control arm and to replace the rubber bushing with a urethane one.

control arm in-board


Here, the pitman arm has been dropped.  To do so, the three bolts connected by safety wire were taken off.  A good whack and the pitman arm just falls.  A lesson on why you should use high-quality hardware.

pitman arm dropped


The castelated nut with the cotter pin through it is what connects the top of the ball joint to the pitman arm.  Even for an Arizona car, I was expecting rust here.  The grooves in the pitman arm allow water to get in, and the dish-shape keeps it there.  Nothing but dust in here, though.  And a small dead bug.  The other one didn't look much worse.  This is becoming the main theme of Webby's restoration:  metal has fared well, but rubber has not.  I'll take it.

pitman arm ball joint nut


To remove the ball joint from the pitman arm, I secured the pitman arm in a vice.  With so little rust, it didn't take much to remove the ball joint's castelated nut.

pitman arm ball joint removal


     Getting the ball joint off the pitman arm wasn't difficult.  However, since these ball joints are the original factory ones, each was riveted to its control arm.  Removal required drilling out the rivet, with persuasion from a hammer.  Care had to be taken not to over-drill the rivets and expand the holes in the control arm.  New ball joints come packaged with hardware for attachment.


My gracious helper, holding one of the ball joints.  Notice the broken rivets.  The rubber bell was so shredded on this ball joint that it's now in two pieces, revealing the "grease" inside.

ball joint removed


     The only thing remaining in this teardown is the tie rod on either side that is responsible for moving the pitman arm, and thus turning the front wheels (picture here, attaching the pitman arm to the car).  Each tie rod has two small ball joints and they all looked in a bad way, too.  I ordered some now tie rods, and they come with new ball joints on them.  I just need to pick up a tool or two to remove the old ones.  After that, it's just a matter of cleaning (maybe painting) the parts and putting them back together.  There will be new ball joints and new urethan bushings all around.


     Update:  I got a set of pickle forks and the right sized fork made removing the tie rods a breeze.  I used the blow torch to heat up the outside of the ball joint (mind the rubber boot!) and after a few swift blows with a heavy hammer, the ball joint popped right out.  It's all about having the right tool for the job.


Here's the pickle fork wedged into the crevice of the ball joint.  Heat applied to the outside of the joint on the steering center link (to the left of the pickle fork) and some hard strikes to the fork itself forced the parts apart rather easily.

pickle fork


Steering center link, sans right tie rod.  You can see the exhaust down pipes just behind it.

tie rod removed