Replacing E28 Lower Control Arms

Replacing E28 Lower Control Arms

by Steven Jay Bernstein, BMWCCA #83901


I attended a Driver's School at New Hampshire International Speedway in October 1994. With a high mileage car, I underestimated the actual costs of the school. While the $90 entrance fee was reasonable for anyone considering attending, one must not forget to consider the preparatory costs as well as the costs of repairing damage. The obvious lemma is that the more time/money invested prior to school, the less time/money required after school.

I broke this rule. After not replacing the original lower control arms (containing lower ball joints and lower control arm bushings) with 227k miles on them, I blew apart a wheel bearing. So, instead of spending a gorgeous weekend in the mountains after the school ended, I found myself repairing my broken car. The E28 front bearings are expensive to buy, but they do last about 200k miles. They're even more expensive when your car has ABS (my 1983 doesn't). I limped home and spent the better part of Saturday searching for a new wheel bearing, and Sunday in the Zen Buddhist exercise of conquering the bolts.

Having suffered some pain, and learned a bit, here is the definitive procedure. If you have reasonable mechanical competence, this is surely a do-it-yourself job. I can add this one to the list of "why did I ever consider paying someone to do this??" jobs.

NOTE: This work was done with the rear wheels on ramps, and the front wheels on jack stands (with the floor jack remaining in place... just in case). A lift indeed isn't required, although it would have made the job a bit easier.


  1. Conquer the thru-bolt at the bushing. If yours is rusty, replace it. It's an M12 x 1.5 pitch x 77mm long. Loosen the bolt, although don't remove it yet. Leaving it in place makes it easier to loosen and to remove the ball joint.
  2. Without removing the brakes (unless you are an idiot like me and blew your wheel bearing, too 8^)), remove the 3 17mm bolts at the bottom of the strut tower. This will allow you to access the locking nut holding on the ball joint. It will also allow you to twist around the strut tower to give you adequate access to this nut. This was not intuitively obvious to me, and it ended up being very helpful once I figured it out.
  3. The original nut is the typical cotter-pin style that was made in the early 80's. The new one has the plastic insert. While the ball joint is still pressed in place, a 22mm socket on a 1/2-inch drive breaker bar or torque wrench works quite well. An offset box-end was recommended, but I found it to be unworkable.
  4. Once this nut is removed, the difficult work of removing the ball joint begins. On the driver's side, with a judicious amount of Rost-Off (liquid wrench to you yanks), a ball joint fork, the heat of a mapp gas torch (with a wet sock protecting the thrust arm joint's boot), and a large hammer applied strategically to one end of the lower control arm, it popped out. If you have to apply excessive force, you should support the bottom of this assembly since it isn't being supported by the strut tower (with those three bolts removed). I used my old wimpier floor jack to counter the forces of the blows on the lower control arm. On the passenger side, I cursed in three languages! 8^) But seriously, this one was a humdinger. The trick was to put the nut on the top of the ball joint so that it is held on by maybe a few threads. Then, put back those three bolts holding the assembly to the strut tower. They won't go in fully, because this nut will hit against the bottom of the strut tower. This is the key - I found that if you tighten these down, the strut tower presses the ball joint right out of the socket!!! Simplicity itself.
  5. Installation is the reverse of removal. Get your torque specs from your favorite manual. And follow Don E's advice about tightening the thru bolts with the car on the ground and you'll be all set.

One side note: If you ever need to replace a wheel bearing, don't panic, as I did, if the inner race pops out of the new wheel bearing before you tap it onto the spindle. The solution to reinserting it is the following, thanks to our friend, Roland Freund:

Remove the rear seal. Then remove the bearings, carefully, in its cage. Then slide the bearings around the race and reinsert it. Reinsert the seal, evenly. Fortunately, if the outer race comes out, you can insert it by simply placing it in the hub at an angle, and it slips in place. Also, another hint: To tap the new hub/bearing assembly onto the spindle, *don't* hit the hub or the outer race will surely pop out. Take the 1-13/16 (or 46mm) socket that you used to get the nut off, place it over the outer race, and tap away.

Thanks to Roland Freund for his technical advice, Jim Conforti for his moral support and male bonding (he usually torques electrons and passengers 8^)), and Charles Karnati for the 1-13/16 socket and the torque specs.

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Steven Jay Bernstein
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updated Saturday, July 19, 1997 03:49:18