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Saturday, April 27, 2024

Doug's Domain

Doug Vetter, ATP/CFI

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Friday, June 11, 2010

Rear Suspension Overhaul Update - Parts Returned

Yesterday I exchanged some email with Don.

(Image: Pre-terminated wires and connector required to fix brake wear sensor wiring)First of all, he let me know that he would have the parts ready to go shortly but said he was unable to remove the inner bushing from the lower control arms. The arm is actually split into two pieces in that area and he said he would likely crush or bend the arm trying to remove the bushing. My dealer tech told me much the same thing but I figured that he was saying that simply because the cost of his labor usually requires him to buy new arms vs. new bushings. Guess not. So last night I placed an order with Pelican Parts for Lemforder (OEM) rear lower control arms with bushings pre-installed. The damage? $50 each or about $50 cheaper than the OE versions. The perk? I won't have to paint the lower control arms to get the "like new" look I'm trying to achieve.

Don also offered to do the differential overhaul consisting of new bearings and seals, resetting the lash and a rattle can paint job for $750. We discussed the idea of replacing the mounting bushings and he said that he would do those for the cost of parts. I did a couple quick part lookups on realoem.com and realized that the bushings retailed for about $15 each so I figured I'd go ahead with that option. In for a penny, in for a pound, right?

A few thoughts then ran through my head. Would it make sense to press new bushings into the existing cover? Perhaps not because...

  1. Don would have to waste his time swapping the bushings. Not a cost to me, per se, but a cost to him that I'll ultimately pay for in some way. There ain't no such thing as a free lunch.
  2. I'd have to waste my time running the cover over to the only person I knew with a blasting cabinet -- my aircraft mechanic -- in order to dress the part up enough so it would look at home on the newly repainted case.
  3. There is a reason why BMW does not advocate pressing new ball joints into front lower control arms made of aluminum (a la E46). I won't belabor the point here, but think metal fatigue.
  4. A brand new cover with pre-installed bushings is only $100.

If you've read this far you already know what I did. A new cover and related hardware as well as a speed sensor for good measure is on the way from Tischer (getbmwparts.com). As I placed the fifth order with in them in the last couple of weeks I added a comment to the order form I knew Jason and Evan would read: "How much more do I need to buy before you guys increase my discount level?" :-) I'll spare you the details of the response, but apparently I'll need to buy a BMW dealership if I want a higher discount. Hmmm...if only I had a spare $15 million burning a hole in my pocket.

Today I made some follow up calls to a couple powder coaters. One never returned my call from yesterday and didn't answer today either. The second guy called back but told me that it would take him a bit more than a week to get the parts back to me. That meant if I delivered them Monday I'd waste the following weekend waiting for the parts rather than beginning reassembly as planned. I quickly realized that powder coating just wasn't going to work out, and I would be forced to prep and paint the parts myself using rattle cans. This isn't all bad news. It removes the question of whether the powder coat would interfere with reinstalling the brake guards on the control arms (it's a tight fit as is...can't imagine how would work with 3-4 mils of powder coat). It also will save me anywhere from $300 to $500. And given how I've been bleeding money lately, that's a welcome change of pace.

This afternoon I picked up the control arms and trailing arms from Don. He charged me 2.5 hours and that's not bad considering how long it would have likely taken me to do the job. I paid the bill and took a few minutes to shoot the shit, as it were.

(Image: Closeup of AKG Motorsport rear subframe reinforcement installed)He asked me to confirm I was planning to use the new split type RTAB and of course I answered in the affirmative. He said that was a good choice because the new bushings use a higher durometer rubber than the prior version and the outer diameter of the bushing (uncompressed) is somewhat larger than the opening in the arm. Installing it in the arm compresses the rubber further which helps keep that center metal bushing where it should be. Unfortunately, he mentioned that he has seen cases of the bushings "walking" slightly out of the arm so he said he'll drill a small hole in the arm in an inconspicuous place and install a screw to lock the bushing to the arm. Easy enough to do with a minimum of consequences, given that the arm is steel rather than aluminum.

This eventually led to a discussion of the body / subframe reinforcement plates I had planned to install. He and one of his staff quickly retorted that the chance of the E36 body failing in that way was so remote as to make it not worth the hassle, particularly on a street car, and one with an automatic transmission to boot. This wasn't exactly news, but it was interesting to hear it from guys that race these cars. Don said that the three cars he'd seen damaged were all driven by the "younger element" who tended to slam the throttle around, dump the clutch, accelerate rapidly over potholes and generally abuse the cars on the street or the track. This advice combined with my desire to get the car back in service AND reduce the bleeding coming from my wallet has convinced me to NOT install the reinforcement plates after all. That should save me at least $300 for the mobile welder plus the usual risk of fire that comes along with welding a car with the fuel tank installed. I haven't decided yet whether I'll sell the plates as I may use them eventually, but contact me if interested in a small discount off retail.

Fortunately, welding the AKG Motorsport swaybar tab reinforcement kit on the subframe was easy to do with the subframe removed from the vehicle. As you can see in the picture, Don had his fabricator install the kit and the the work is beautiful. It is better than the Turner kit, in my opinion, by the virtue that it includes an extra piece that is used to box in the structure, thus significantly enhancing the strength of the modification. Truth be told, the kit is overkill for a street car equipped with the stock rear swaybar, but you really didn't think I was going to keep that on there forever, did you? After all, there is a method to my madness.

This weekend I plan to:

  1. Install the new brake wear sensor wiring I picked up from the dealer this morning (pictured)
  2. Scrub the underside of the car's body while I have the opportunity
  3. Prepare, prime, and paint all the parts I'll take back to Don on Monday morning

Mileage: 193332, Parts: $205, Parts Saved: $80, Labor $235