December 5, 2006
Jeez. I can't believe it's December already, but that's a good thing, because it means in less than a month the days start getting longer again and in another four months or so I can stop freezing my butt off in the garage working on the car. Anyway, lots to talk about today, so let's get started.
Pilot Sport A/S Wins Again
I wrestled with the choices for a long time, but today I finally managed to pick up new tires to go along with the new CSL wheels I purchased back in August.
The first issue I had to resolve was the proper size for this non-standard application.
My E46 came from the factory with 225/40/18 on the front (on an 8" wheel) and 255/35/18 on the rear (on an 8.5" wheel). In my opinion, the front tires appear slightly stretched over the wheel. However, it is a factory-approved configuration. If the CSL wheels were 8" wide, I would have bought 225/40's and called it a day -- but they are, in fact, 8.5" wide. It stands to reason that if the 225's looked stretched on the 8" wheel of the E46, they'd look ridiculous on the 8.5" CSL wheel. I saw several pictures on e46fanatics.com that confirmed this belief.
Complicating this issue is the fact that not all 225 series tires are created equal. The so-called section width (effectively the width of the tire measured at the widest point in the sidewall) varies among tire manufacturers and models of a given manufacturer. The typical range for a 225/40 series tire is 8.8-9.2 inches, so simply put, you have to look at the specs for the tire as well as the standard tire sizes if you need to reduce the impact of the "stretch effect".
While the Pilot Sport tires tend to run wide and look a lot better on an 8.5" wheel as a consequence, I don't think they're wide enough. For this reason, I ultimately decided to upsize to 235/40. Since the 235/40 series tire is slightly taller than the OE 225/50/16 I'm running right now, the speedometer will read 2.2% lower, and that will cause a corresponding decrease in the odometer reading (about 450 miles over the lifespan of the set if we ignore the effects of normal tire wear). The interesting part is that BMW speedometers tend to read 3-4MPH too high on average, so the error introduced by the non-standard fitment reduces the effect of that error.
Trivia: The built-in error in the BMW speedometer is only present in the analog instrument. The optional OBC in my vehicle will, if repeatedly cleared while in the SPEED mode, show the "real" speed of the vehicle. Don't ask me why BMW did this. Some suggest it was the automotive equivalent of setting the time on one's clocks five minutes ahead to ensure you're always five minutes early. And yes, it has just about the same effect in the car too, since I typically add about five MPH to the indicated speed to make sure I'm driving at the posted limit.
The second thing I wrestled with was the brand of tire.
As I indicated in an earlier log entry, I had narrowed my choices down to the Michelin Pilot Sport A/S and the Pirelli PZero Nero M&S. Both brands were available in 235/40 fitment and both came highly recommended. A colleague recently purchased a set of Pirellis for his 5 series and has been happy with them. And here's the kicker -- the Pirellis were nearly $100 less expensive per tire. Since my money is busy doing other, more important things right now, I was a bit more price sensitive than usual. But, when all was said and done, I coughed up the cash for the Pilot Sport A/S. Why? The quality of tire construction is much more important on low-profile tires and Michelin is well known for producing true tires. The downside is that five tires came to a bit over $1300 with shipping. That's one serious hunk of change and the most I've ever spent on tires.
I had briefly considered buying the non-directional Pirelli PZero Nero M&S for the spare to save a few pennies, but figured I'd keep the brand the same so I could rotate the spare with the right rear (which tends to wear slightly faster than the left rear due to the open differential) and not have it look ghetto. A local tire rep also told me that if I really had to, I could run the directional Pilot Sport the "wrong way" for emergency purposes without any negative effect on the tire itself. I would only need to be cautious in inclement weather. That's good news.
Finally, logistics of delivery, mount, and balance
I originally planned to have Tire Rack drop ship the tires to my dealer and bring the wheels to them for the mount & balance. My plans were put on hold when I was informed that the new owners had raised the price to mount and balance a tire from a high, but acceptable $40 to the ludicrous sum of $75. Yes, you read that right. $75 PER TIRE. Their rationale? BMW book labor is 0.7 hours per tire, and people will pay it. Except me, of course. I learned some time ago what equipment King used to mount my tires, so it didn't take long to find a website that allowed me to search for registered operators of Hunter balancing equipment. I found a local company with the same equipment as my dealer that was willing to do the same job for $35 each.
I figured I'd just give the job to the indy shop, but since I'm not one to take no for an answer, I decided to go see the dealership service manager. When I arrived, I discovered that the service manager I'd known for many years (but never had to talk to regarding any service problem if you can believe that) had quit. I greeted the new manager and sat down with him to discuss my issue. He took my phone number to look up my records, then made a few comments about the long history I had with the company and the fact that he had seen me around the shop more than a few times. He asked me whether I had bought my cars there and I replied in the affirmative. We then discussed the fact that I thought $75 was excessive. I believe my sentiment was "I'm not a prude with my money, but I'm not stupid with it either". We also discussed what I wanted to do, and I emphasized that King management never had a problem with accepting drop-shipped tires because they knew I'd never buy from them anyway (thus it was no loss to them). After about 10 minutes, he finally relented and said in the interest of continuing a good business relationship with me that he would reduce the cost for the mount and balance to $40/tire.
I concluded the meeting with the impression that he didn't seem to think that the original price was abnormal or excessive. On one hand I can see that it is the duty of every business to charge what the market will bear, but on the other, the hippie in me suggests that there's a line between making money and outright greed -- and the dealership had crossed that line.
The tires should arrive at the dealer in the next couple of days.
Custom Sway Bar Link Wrench
The front sway bar links connect to the front sway bar using a ball joint. To prevent the base of the joint (the bolt) from rotating when trying to remove the associated nut, you need a 16mm open-end wrench with a thin profile. My technician told me that although BMW provides a special tool for this purpose, in reality he uses a custom tool he made by grinding down a 16mm wrench. I bought a 16mm wrench from Eppys that I plan to sacrifice for this purpose, and while $10 is a lot to spend on a tool just to hack it up, it's cheaper than the BMW tool by a long shot. I'll talk more about that tool when I do the links.
Back to the Body Shop
Looks like I'm headed for the body shop -- for a third time. I came out from work tonight to find that the car had been sideswiped by a moron who parked next to me and decided to crank his wheel a bit too hard over while backing out. I didn't see who did it, and he didn't bother to leave a note with his information as required by law. In other words, it was a hit and run.
A bit of bad luck, I suppose, but as usual I plan to unravel the mess and spin it into gold:
- The driver's door was one of the most poorly finished aspects of the vehicle, leftover from the first deer hit. This will be an opportunity to strip and repaint that door. The protective moulding on the car prevented a LOT of damage from occurring on the door panel itself (BMW Design Group -- are you listening?), but the moulding took a serious beating and will need to be replaced. Fortunately the old one was already damaged from yet another idiot who opened his door into it, so it needed to be replaced anyway.
- I may repaint the passenger door so it doesn't look like total crap in comparison to the driver's door. All I'm looking to do is get rid of the foggyness and drips in the clear that the first shop said was "normal". Yea, whatever you say -- moron.
- The mirror covers were repainted by the same moron following the first deer hit. Six months later, that shop wound up repainting the covers under warranty after they started chipping. Over the last several months the paint has started to flake off the covers again, so I had considered buying new covers and having a reputable shop paint them up for me. It looks as though we'll have an abundance of paint with which to do that.
If you've ever wondered why I have two cars and I don't commute with the E46, this is why. Breathe. Deeply. Relax.
Mileage: 136250, Parts: $1303
December 10, 2006
CSL Replica Wheels and Tires Installed
The Pilot Sport A/S tires showed up at my dealer on Thursday and I arranged to have my tech mount & balance them Friday. I threw the wheel boxes in the back of the pickup truck and took them to the dealership before work. As I transferred the boxes to my technician's bay, he commented on the utility of a pickup truck in such situations. With a straight face I replied "yea, this truck is awesome...it goes 0 to 60 in FOREVER. The only problem is if I drive it for more than 30 minutes at a time, I lose the ability to do complex math!" He chuckled as I broke into a smile.
While my technician finished the job later that day, I couldn't get away from work until later that night, so I figured I'd take advantage of my dealer's new Saturday hours to pick them up.
After a brief diversion to my county HazMat facility to drop off some old paint, household cleaners, a long-dead car battery and some used motor oil, I arrived at the dealership Saturday morning to find that my technician had stacked the wheels in one of the rear bays in the shop separated by pieces of cardboard as requested. As I carefully loaded them into the back of the pickup truck, a couple of techs wandered by. One guy commented that they looked good. I explained the fact that while they're replicas made in the far east and lack the casting quality and finish of the OE wheels when viewed up close, they admittedly look good at typical viewing distances, get the job done, and are about one-third the price of OE wheels (that is, assuming, you wanted to put up with 19" wheels, as there is no such thing as a 18" CSL / competition package wheel).
Upon closer inspection, I found my technician had to use anywhere from 0.5oz to 1.5oz of weights to balance them. I'm not sure whether this was due to casting irregularities or tire issues, but he was able to balance them with a minimum of weight by placing the weights on the outside edge of the wheel. It's certainly possible to put weights inside the face of the wheel where they are less noticeable, but weights are most effective when placed on the outside edge. This isn't a particularly attractive option, but I asked my technician to use his best judgement. My opinion is that looks take a back seat to function when necessary, and that's particularly true in the case of wheel weights since I can't see the weights when I'm driving (and truth be told, no one else can either).
A couple of hours later, I managed to install the wheels. They went on the car easily enough, and I noticed the hubcentric design fit the hubs snugly. This is important because a close fit in this area is required to prevent vibration or other problems that detract from the driving experience.
So how's it drive? In a word: great. I was very concerned about how low-profile tires would affect the vehicle's well-balanced stock handling characteristics because this car is my daily driver. While I like the E46's ZHP suspension and it's a blast to drive fast in the twisties, I can honestly tell you that I do find it fatiguing to drive for a number of reasons and I did NOT want to recreate that feel with the E36. On the test drive, I was relieved to find that the car drove like it did running on the 16" wheels with a few minor exceptions.
First of all, I do feel more defects in the road through the steering wheel (front tires) and the "seat of my pants" (rear tires). This is to be expected with a shorter and stiffer sidewall. The tires are simply communicating more of those defects to the wheels, which are then transmitted through suspension components to the body structure. The ride is still perfectly smooth and is not jarring in any sense like the ZHP can be under certain conditions.
The turn-in is radically improved, as one would expect from larger wheels to spread the load, slightly wider tires, and a stiffer sidewall. The tires don't have as much "give" and when commanded to turn, they turn. I haven't yet explored the limits of the tires because I need to let them break-in first, but if the first few turns are any indication, the wider tires and wheels on the front of the car will significantly reduce understeer and therefore increase turning performance.
The pleasant surprise was the noticeable lack of steering instability that occurred with the 16" Pilot Sport A/S. Let me explain what I mean. Long time readers will remember that the car came from the factory with a summer tire, the Dunlop SP2000. I replaced that with a similar high performance summer tire, the SP8000. While I've forgotten how the SP2000's drove (yes, it's been nine years -- give me a break) I do recall that the SP8000's tramlined badly. I didn't have enough experience with the BMW (and, admittedly, cars in general) at that time to recognize the condition as a function of tires, but it was one of the reasons why I ultimately chose to replace it with the Pilot Sport A/S in 16x7, 225/50 fitment.
The Pilot Sport A/S cured the tramlining problem and returned the classic BMW "neutral" steering feel. Unfortunately, at times I felt the steering to be almost "too neutral". Call it "loose". Based on my short-term experience with the new wheels and tires, I can now say that the gyroscopic effects of the larger wheel mass combined with a stout, stiff sidewall perfectly stabilize the steering in the neutral position and contribute to an overall sense of steering precision that the car simply lacked up to this point. In that sense it steers a bit more like the E46, but is actually far more comfortable to drive for long periods because of the lower-ratio steering rack. To put it another way, the E36 has a slight deadband around the neutral steering position. The E46 does not.
The one negative is that acceleration is reduced slightly, but that was expected. The car has to get a lot more mass moving and that mass is farther away from the center of the hub. It's a simple matter of physics. On the upside, the one "radical departure" I made did not spin the wheels, so ASC never cut in, and the result was a nice, smooth, fast departure. Larger wheels won't help the quarter mile times, but I don't really care about that. All I *do* care about is ride quality, minimizing understeer and increasing overall traction in the twisties, which is where this car shines...as is the case with most BMWs.
How does it look? Amazingly good considering the wheels were not designed specifically for the E36 body. They give the car a more aggressive, yet classy, look. While the body designers recently enlisted by BMW clearly need to see the business end of a .357, I have only praise for the wheel designers. BMW's wheel designs have become progressively more interesting and remained tasteful and classy at the same time. I mean, does anyone remember what the E36 "bottle caps" looked like? Egad. The sport-package double-spoke 16" wheels were the best-looking wheels of the day and still look great on the car, but it's safe to say the 18" CSL design tastefully advances the look of the E36 and brings it into the current day.
So how's the stretch, you ask? Fine. I'm really happy that I chose to go with 235/40's on the 8.5" wheel. The protective ridge of the tire extends just beyond the rim of the wheel. It's not enough to protect the rim in the event I curb it, but then again, neither was the 255/35 on the rear of the E46. You just have to accept the fact that curbing these wheels costs money, and you need to do everything in your power to avoid doing so.
Brakes Inspection and Followup
This week I'd noticed that if I pressed lightly on the brakes as I slowed to a stop, one of the brakes would squeal. It was very faint and happened only once every 10 stops or so, but it was enough to convince me I should pull the calipers off and apply some additional Plastilube grease on the contact points between the pads and the carrier bracket. I did this at the same time as the wheel swap for obvious reasons.
I'll admit that I did not put a lot of Plastilube on the carrier brackets originally because my technician suggested that the job required very little grease in general, but after looking at the TIS (BMW service information), I realized I didn't coat some areas BMW recommends. With that new found knowledge, I added grease in the proper points and reassembled the brakes. Naturally, the calipers came off very easily this time because no ridge had yet formed on the rotors. In fact, it took me less than five minutes to complete the operation per wheel. I can now see why people find it easy to change pads at the track. If you're not taking off the carrier bracket, etc, R&R'ing the calipers really takes no time.
The downside? During the test drive with the new wheels, the brakes squealed again. Not sure what the problem is. It may just be a characteristic of the OE pads I received (they do reserve the right to change the formulation), but more likely there's just something I've done wrong, as I have NEVER heard the brakes squeal on this car. If I come up with a cause and solution you'll read it here, that's for sure.
Mileage: 136480, Labor: $217
Monday, December 18, 2006
CSL Replica Valve Stem Issue
Last Saturday I was finishing my weekly car washing ritual and cleaning tons of fresh brake dust off the new CSL wheels for the first time when I discovered a potentially serious problem. As I pushed the sponge into the crevice between the valve stem and the wheel, I heard a hissing sound. I pulled the sponge away and the hissing stopped. I then grabbed the valve stem and rocked it back and forth. Hiss. Hiss. Hiss.
A quick pressure check found not one, but BOTH, rear tires at around 14 PSI, while the fronts were near 33 lbs as I would expect. I couldn't believe my eyes, so I checked it again. Same results. 14 PSI is way too low for a low profile tire. And in fact it's low enough to permit the tire to dismount from the wheel under load. I looked more closely at the sidewall of the rear tires and found they bulged outward a very slight amount as compared to the front tires, but not enough to communicate the severity of the problem. That's when I realized low-profile tires do not exhibit the signs of underinflation the way the 16" or smaller tires do.
The valves were obviously the cause of the lower pressure, but I couldn't immediately explain the disparity between the front and rear tire pressures. If this was a simple matter of centrifugal force, as a function of speed, pushing the stem outward and causing a leak, why didn't the front tires lose pressure?
I then remembered a similar case involving the E46 M3. People were bitching about the fact that the valve stem caps were contacting the wheel and marring the finish, and the problem was concentrated on the rear tires. It turned out that it had more to do with the wheel hop that occurs as the vehicle quickly accelerates and the tires claw for grip, or when the tires go over a bump in the road. The solution involved, from what I recall, installing fixed metal valve stems.
Later that night I sent email to the wheel distributor as well as to e46fanatics.com in search of information. The consensus was that the valves were improperly installed -- they simply weren't tightened enough. When I asked the distributor for a torque spec, he confessed he didn't have one. It appears the stems are installed "tight, but not too tight" and with a delicate sprinkling of pixie dust for good measure. I emphasized the critical nature of this problem and the liability it represented, but the distributor pointed out that he had not heard of anyone's stems leaking. One guy on e46fanatics admitted that while the stems on his car leaked in the same way as mine, he hadn't lost any pressure other than the normal and expected 1-2PSI per month. Guess I'm the first to experience this problem. Lucky me.
I went to the dealer first thing this morning and discussed the matter with my technician. He apologized for the error, but pointed out that lacking a torque spec, he tightened the stems as far as he thought prudent, as he didn't want to crush the o-ring and destroy the seal they're designed to create. Truth be told, the stems were tight and barely moved...but just weren't tight enough. We discussed the option of replacing the stems I provided with metal and rubber stems he installed on a daily basis, but we were also conscious of the fact that changing stems would affect the balance, and neither one of us wanted to rebalance the wheels unless absolutely necessary.
My technician agreed to address the issue as soon as I could get the wheels to him, so the plan is to drop them off tomorrow morning. For logistical reasons I may not put the wheels back on the car for some time, but I'll report on the fix in a few days.
I just learned that my company is shutting down during the week of Christmas, so I plan to leverage the extra time to do some needed work on the car. I'm planning to do:
- Oil Service
- Spark plugs. The car originally came with copper electrode plugs, but BMW now recommends platinum plugs. Many people have had good luck with the recommended NGK units and more rough idle issues with the Bosch equivalent, so I'm planning to install new NGK units.
- Plug Sockets - these are insulated conductors that connect the top of the spark plug with the associated coil. The insulation tends to get brittle over time and can, under certain conditions, crack and cause arcing between the coil and the valve cover that results in misfires. I don't have any misfire issues, but it makes good sense to replace them while I'm in there.
- Valve cover gaskets (VCG) - I don't have any noticeable leaks, but then again I haven't pulled the plugs in almost 72K miles. Since doing the valve cover gaskets requires similar disassembly procedures as the spark plugs, now is the time to do it. I've heard that R&R of the VCG kit is pretty easy as long as you're neat about your work.
- Stabilizer (Sway) Bar End-Links - As I mentioned in a previous log entry, it's time to do these. I'm really hoping this will tighten up the front-end and give me some idea as to whether I need to do control arms and suspension work this spring.
I used realoem.com to find the myriad parts required for these tasks and put them in an email to Jason at Tischer BMW for a quote. Due to shipping costs, however, I'm planning to pick up the oil from my local dealer.
The last oil service was what I call a "mid-cycle" change, in which I don't reset the oil service indicator. This time I'll need to clear the indicator, so I figured it was time to acquire my own means of doing that. I've known for some time this amounted to grounding pin 7 of the diagnostic connector (under the hood) for a specific period of time (3 seconds for oil service, 9 for inspection), but I never bothered to concern myself with this because my dealer always took care of it.
Based on some great information I learned that BMW sells a short length of wire with a pin crimped on one end designed to fit the diagnostic connector. At less than $2, I figured this was better than buying those ridiculously overpriced $50 commercial service reset tools, so I included that part in the parts order as well. All I'll have to do is attach an alligator clip to the end of the wire and I'll have a $5 solution to this problem. I don't have a category in my "bottom line" reports for "tool savings", but if making my own tools becomes a regular thing around my garage, I may just add one.
The parts quote came back at $280. While that's a lot of money, it's a great deal for what I'm getting. Labor for the equivalent work would probably be at least twice that, so I think doing this work myself will make good fiscal sense. The parts should be here the middle of next week.
Mileage: 137000, Parts: $280
Wednesday, December 20, 2006
CSL Replica Valve Stem Issue Followup
I brought the wheels to my technician yesterday and picked them up this morning. The good news is that my tech was able to tighten the stems by simply deflating the tire and breaking the outside bead only, and doing so was easy enough because the mounting lubricant hadn't completely bonded the tire to the wheel. Since the tires weren't shifted on the wheel and we were able to use the original stems he didn't have to rebalance the tires.
Upon closer inspection, the stems still move around a bit, but they don't leak. This proves my assertion that there is a "sweet spot" of sorts, achieved at a specific torque, that is tight enough to prevent leaks, but loose enough not to split the o-ring. I still do not know what the "official" torque is, and I don't think I ever will know, apparently because the manufacturer assumes this is too trivial an issue to warrant any concern.
The assumption is that installers will just "know" how to install them properly, and if not, it's the installer's fault. That attitude is strangely reminescent of programmers I've worked with that write bad code, don't document anything, and then just expect the customer to "deal with it" in the field. I just hope for the manufacturer's sake that they start providing the necessary information to new customers or they may find themselves the target of a lawsuit when someone loses their car (or worse) over this. Think it can't happen? Think Firestone and think again.
All I can do at this point is communicate what I've learned so this doesn't bite anyone else:
- If your car is not equipped with a tire pressure monitoring system (TPMS), check tire pressures daily for a few days following the installation of new wheels, tires, or valve stems and then once weekly thereafter as part of normal maintenance.
- If you have metal valve stems, try to move them around a bit. If you hear ANY air leaking, get them to a tire shop and have them tightened. Centrifugal force -- and in particular, wheel hop due to rapid acceleration or bumps in the road -- can push the valve stems out and cause a leak. The leak may be only a momentary thing, but the effects are obviously cummulative and can have disasterous consequences on a high performance car if left unchecked. A BMW ain't no minivan.
- There's nothing wrong with rubber stems. In fact, I prefer them because they naturally seal against the inside of the wheel (they're a press fit), while metal stems rely on proper torque and one or more o-rings to maintain the seal. The KISS principle applies here as well as anywhere.
And speaking of tire pressure, it's not entirely clear what pressure I should be running in these tires. The E36 came with 15, 16, and 17 inch wheels over its lifetime, and the inflation data for those sizes is available on the door frame. The only data I have for 18" wheels comes from my E46, which specifies 32 lbs front / 38 lbs rear, but that is hardly applicable to the E36 due to differences in vehicle weight and wheel / tire sizes. I'm considering 34/36 lbs to start, and plan to closely watch tire wear, particularly on the rear. I used to run the 16" tires at 32/34 and have noticed the Pilot Sport A/S has worn a lot more in the center of the rear tires. This could be due to the softer compound used in the center of the tire, overinflation, or perhaps a little of both.
Thursday, December 28, 2006
Right on schedule, I did my second DIY oil service. The job was a bit easier this time around for a few reasons:
- I put the front of the car on jackstands which, even at their minimum height, puts the car higher in the air and makes the drain bolt more accessible.
- I was able to use my 3/8" drive torque wrench to apply 18 ft*lbs to the drain plug because I bought a 3/8->1/2" adapter. The 3/8" torque wrench is physically smaller and easier to manipulate under the vehicle. It's also more accurate at that torque setting.
- I was able to quickly remove the large o-ring on the filter cannister and the two smaller o-rings that go on the central shaft of the cover with the small pick set I bought a few weeks ago. Incidentally, I don't think the small o-rings had been replaced for the life of the vehicle because they were very brittle and actually snapped as I tried to remove them. Note that these o-rings are not included in the oil filter kit, so if you want to replace them you'll need to order them separately.
This was the first time I had to reset the service indicator lights. As I indicated earlier, I used a special wire assembly sold by BMW to short pin 7 of the diagnostic connector to ground to reset the lights.
I only had one snag. You're supposed to short pin 7 for three (3) seconds to reset the OIL SERVICE indication but that didn't work. I did it again and that still had no effect. I did it a third time and the display changed to show "INSPECTION" and the bar graph changed from showing one green bar to one yellow bar remaining. This may very well have occurred because the car was ready for inspection rather than an oil service, but I lost track. I then decided to short the pin out for a continous period of nine (9) seconds, and that reset the lights properly. Since I don't really use the lights anymore other than as a general reminder to check out my maintenance schedule spreadsheet, if I reset both oil and inspection lights each time, that's fine with me.
Mileage: 137310, Parts: $36, Labor savings: $70
Front Sway Bar Links
This was a straightforward task with one exception. When checking realoem.com for the front sway bar parts I saw only one option for the bushings -- 24 mm. I knew that one of the attributes of the sports package on this car was a larger swaybar, so when realoem.com showed a "low-slung suspension" option for an 18mm rear bar, I figured that was the only difference. While I had the car jacked up for the oil change, however, I took a close look at the front sway bar bushings and saw "25.5" stamped on them. so it turns out that BOTH swaybars are larger on the sports suspension and the front is 25.5mm rather than 24mm. This meant I had ordered the wrong parts.
Knowing that some BMW parts are "phantoms" (that is to say, not shown in the parts diagrams of the ETK, but otherwise available if you enter the part number manually), I looked for a part number on the bushing. I managed to clean up the side of the bushing sufficiently to see a few numbers, but they didn't resemble a BMW part number so I didn't bother to copy them down. I went to the dealer's parts department on the assumption that realoem.com was out of date. It turned out that their latest ETK software provided the same (incorrect) information.
While hanging around the parts desk I ran into my technician. Always accomodating, he offered to put his lunch aside, put the car on the lift, and remove one of the bushings to look for a hidden part number. The only numbers on the bushing he found aside from the size (25.5) were the numbers I found earlier. He brought those numbers over to the parts desk and the parts guy was able to come up with a full part number and enter it into ETK manually. The good news at this point was that the part was available, but they didn't have any in stock, so my technician had to put the old ones back on the car.
While he had the car up on the lift, I asked him to take a quick look at several things -- trailing arm and subframe bushings, front lower control arms & balljoints, and tierods. He said that he "never" replaces the trailing arm bushings, which is really his way of saying they're a very rare fix in this shop. He also said that when the subframe bushings fail it's obvious, but mine weren't sagging at all -- they appeared to be in good shape. To finish up, he did the usual tug on the front wheels and gave the ball joints a clean bill of health. When I mentioned the problems I was trying to solve, he commented that at roughly 75K miles on the struts he felt they were about 3/4 of the way through their useful life and were the most likely culprit. Struts are now on the list for work I'm planning for the spring.
Back at home, I figured I'd just reinstall the new CSL wheels (with fixed valve stems), but once I pulled the front wheels off I realized that I could replace the end links now and do the bushings later without removing the wheels at that time, so that's what I did. It took me about 20 minutes to do the first link because I had to file down my 5/8" sacrificial combination wrench I bought the other day for this purpose, and just figure out what sizes of wrenches and sockets I'd need for the task. The second link was done in less than 5 minutes.
I originally decided to replace the sway bar end links because I thought they might be reponsible for the "shudder" I felt in the steering wheel as I drove over rough pavement, particularly when turning. After a few hundred miles of driving it's clear that the shudder is gone and the steering appears a bit smoother overall. As a result of this experience I've changed my recommended maintenance interval on end links to 72K miles.
I have yet to tackle the rear bar, but that will come soon.
Mileage: 137400, Parts $100, Labor Savings: $100
Body Shop Estimate
As you may recall, an unknown moron sideswiped the driver's side in a parking lot at work a few weeks ago. I took the car to the same shop that did the work earlier this year and settled on a plan to repaint the driver's side door and blend into the quarter panels, replace the driver's door pull trim and bump strip, the lower skirt and the two mirror covers. The damage? $1600.
This was technically considered an accident even though I was no where near the car when it happened, so my $500 deductable applied. The most I could hope to get from my insurance company is $1100, but it's likely they would refuse to do the job to my satisfaction and come up with their own, far cheaper, estimate. In addition, their bean counters would likely count this as an accident, even though it was a hit-and-run and the reps told me it wouldn't count against me. I pay less to insure both of my cars now than I used to pay to insure the E36 when it was new, so any money I might hope to get from my insurance is not worth the risk of a long-term increase in premiums.
The shop offered to take the car in next week, and my guess is that the work will take about two weeks to complete.
CSL Wheels Reinstalled
I decided to put the CSL wheels back on the car so I could put the valve stem issue to bed and also to test the new end links. The good news is that the valve stems appear to be holding air at 36 PSI and the end links quiet the steering shudder on the 18" wheels as well. The bad news is I'll have to remove the wheels again before I take the car to the body shop, as body work is a messy business and I don't want any sanding residue or overspray on them -- especially after all I've been through to get them on the car.
Saturday, December 30, 2006
Front Sway Bar Bushings
The new 25.5mm front sway bar bushings came in so I picked them up and installed them today, and in doing so completed the front sway bar service. The steering is even smoother than it was before, and I honestly didn't expect much of a change because the old bushings, while slightly deformed, seemed to be in generally good shape.
The inner diameter of the new bushings fits the bar snugly, and the only issue involved fitting the bracket over the new bushing. The outer diameter of the bushing is slightly oversized so that tightening the bracket squeezes them against the bar to hold it tightly. I suppose in retrospect I could have used some sort of rubber lubricant that will dry out (my technician says Spray-9 works perfectly for this task) and cleaned up the bracket a bit, but I just used a hammer to gently tap the bracket over the bushing.
I then pushed the entire assembly up to the studs in the frame rail and threaded new nuts without difficulty. I noticed that this process initially opened up the split in the bushing a bit more than I expected, but the gap closed up again as the nuts reached their final torque of 22Nm or 16 ft*lbs and the bracket compressed the bushing against the bar.
For what it's worth, after 137K miles, the rubber in the old bushings was perfectly pliable...it was merely compressed in areas subject to the greatest stresses. Given the outcome, how inexpensive the parts are, and how easy it is to replace them, I recommend the bushings be replaced when the endlinks are done.
Mileage: 137600, Parts: $10, Labor savings: $80
Power Steering Hoses
While the car was jacked up, I figured I'd take some pictures I needed to update the power steering flush article. And that's when I noticed leaks from both hoses on the bottom of the reservoir as well as some wetness around one of the fittings on the pump. The common denominator? Each fitting still sported the original BMW crimped clamp used during manufacturing nine years ago.
As I took a closer look at the hoses I noticed that the metal portion of the return line (the coil) was in bad shape too, except this had more to do with corrosion. I figure it will be just be a matter of time until this fails, so I expect to replace the hoses soon and do a flush as well. Of course, I don't expect things to be that easy. There's a distinct possibility that attempting to liberate the hoses from reservoir will break the nipples on it, so I plan to replace the reservoir as well. All told I'm probably looking at $150 in parts, but I'll probably save twice that again in labor doing it myself.
Year In Review
This will be my last maintenance blog entry of 2006, so I figured I'd reflect on the past year.
First of all, I've learned more about BMWs and auto maintenance in general in the past year than I had in the past 20. This has been a great educational experience. As with most new subject matter, I've regularly experienced the learning paradox -- the more I learn, the more I realize I don't know -- but that drives me to learn more and take more risk in the pursuit of that knowledge.
This year has seen the BMW portion of my site grow substantially. This is the first year that I've had something to say (good, bad, or indifferent) every month of the year. I've quadrupled the average number of unique site visitors and I've doubled my average bandwidth usage. dvatp.com is still a small site by most standards, but it's definitely becoming more popular -- for all the right reasons I think.
The interesting thing I've noticed is that search strings increasingly contain the specific terms "Doug Vetter", "Doug's Domain", or "Doug's BMW" (as opposed to generic terms like "diy bmw brakes", which tells me that people may not know my site URL, but they know my name and what I do. If this continues, pretty soon I'll be so popular that I'll find myself on the same social strata as the girl of my dreams. Incidentally, if you see my contributions here drop off precipitously at some point next year, it's likely because she's answered my prayers (or maybe those 1000s of stalker emails) and I'm busy with both hands on her rather than this damn insensitive keyboard. *sigh*. Back on topic.
I have several goals in the BMW space for 2007. I want to wrap up the restoration of the E36, increase the work I'm comfortable doing myself, and do whatever I can do to reduce the cost of ownership. After all, I have big plans for my money over the next several years and the less money I spend on maintenance (without compromising quality or safety, of course), the better.
To all the regulars, thanks for reading. I do this stuff for you. Here's to a great 2007!