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Tuesday, April 23, 2024

Doug's Domain

Doug Vetter, ATP/CFI

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Saturday, June 30, 2012

Front Suspension Overhaul - Day 10

This morning I stopped at Eppys to pick up a small set of cold chisels and a manual impact screwdriver (total: $60) to aid in my assault on the fracture bolts. I then stopped by the dealer to pick up a few odds and ends I ordered last week. When the receptionist smiled and feigned disappointment in me for spending less than $100 I realized I might be spending too much time and money there lately. Fortunately, I think it's safe to say I'm largely done buying parts for this project and I shouldn't need to make too many more trips to the dealership...that is until I start the "lower interior overhaul" project I have planned for later this year.

When I arrived at the garage I once again tried to attack the fracture bolts, this time armed with my new impact screwdriver. The good news is the tool worked as exactly as it should, but the bad news is it still failed to remove the bolts. I'm now planning to follow the advice of reader Brian, who kindly provided photos and a great description of the technique he used to remove the bolts. According to his technique I've done half the work already by cutting the slots deep into the heads. Now I simply need to cut half of the head off, continue cutting slightly into the other side of the head, and finish up with a chisel to break off the other half of the head. That should allow me to pull the column and then unscrew the remaining studs. I decided against continuing with this today since it was way too hot in the garage and doubly so in the car with little air circulation.

Incidentally, I received the high strength M8 bolts from McMaster-Carr that I plan to use to replace the fracture bolts, but I bought OE fracture bolts as well to serve as a means of comparison. More on this topic when I finally get the column out of the car.

With the fit bolt nuts in hand I decided to install those nuts and torque all the fasteners on the front end to spec. Here's a list of the torque specs and some comments:

Before I installed the brake shields I decided to test fit the ABS sensors in the kingpin bores. Neither sensor fit particularly well (what a frickin' surprise) so I installed a sanding drum in the Dremel and cleaned up the bores, after which the sensors fit cleanly and easily. I plan to apply a thin film of grease to the bores to help prevent the sensors from bonding too tightly with the kingpins. I decided against installing the sensors for now because I knew they would just get in the way.

In preparation for installation of the wheel bearings I installed the bearing dust shields, which must be press-fit to the stub axle. I tried to press the shields on by hand but quickly realized that wasn't going to work. As I walked around looking for what might pass as a drift the dusty five watt light bulb illuminated over my head as I passed a pile of old PVC electrical conduit. I found a piece of 2" schedule 40 conduit that matched the diameter of the shield nicely so I used that to install the shields on the car in only a couple minutes' time. Check out the video for the technique.

With the dust shields in place I finally got to use the BMW special tool I acquired many years ago to install the wheel bearings. As it turned out the fit between the left side stub axle fit and bearing was very tight so the tool was clearly needed in this case. I used the tool on the right side but the fit was loose enough that I was able to hand tighten the tool's nut to press the bearing to the shaft. All in all the tool made a potentially difficult task very easy, which is typical of most BMW special tools. Check out the full video explanation of how the tool works.

Next up is installation of the brakes and repair of the steering column. Once the column has been reinstalled I'll finish up by assembling the steering system, bleeding the brakes, and taking it out for a test drive.


Mileage: 222600, Parts: $43