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Thursday, August 28, 2014

Doug's Domain

Doug Vetter, ATP/CFI

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Saturday, July 21, 2012

Front Suspension Overhaul - Day 17

I began the day by using a new technique to install the snap ring at the top of the steering column. Traditionally this is an annoying, trial and error process because the steering shaft must be pulled against spring pressure while the snap ring is maneuvered into place. As luck would have it, a reader suggested a way to simplify this process: use a 1.5" long piece of 3/4" schedule 20 PVC as a drift in combination with the steering wheel retaining bolt to press the c-clip into position. The reader was nice enough to offer to send me a piece of pipe but I figured I could find what I needed at the local home center or plumbing supply store. As it turned out Schedule 20 PVC is no longer stocked anywhere.

Never one to give up, I grabbed some spare Schedule 40 electrical conduit and used the Dremel equipped with a sanding drum to sand the inside of the pipe down as required to fit over the splined shaft. I installed the makeshift drift onto the splined shaft, threaded the steering wheel retaining bolt into the steering shaft and then used a ratchet to tighten the bolt until I witnessed the pipe stretch as required to push the snap ring into the groove -- exactly as expected. Thanks for the idea Brian!

After this I reinstalled the steering column covers, steering wheel, airbag, footwell crash protection panel and, lastly, the footwell cover there was nothing else to do but re-attach the battery terminal for the first time in nearly two months and witness the car come back to life. A quick check of the engine bay revealed no stray tools so I got back in the car and anxiously turned the key. Not surprisingly the seemed eager to get back to business as it fired instantly and only misfired a couple times before it settled into the characteristic smooth idle.

Before I set out on the test drive I checked the level in the power steering reservoir, which can be done without fear of spraying ATF everywhere, incidentally. The level was low enough to expose the filter so I filled it to the proper level and rechecked it before I got back in the car once again, put it into gear, and pulled it out of the garage. Looking over the hood as the car rolled the first few feet I could see the front-end slowly drop as expected. Always cautious, I ran the car back and forth in the driveway to test the steering and brakes before I took it out on my local residential test loop. Despite the alignment being out of whack and having to hold the wheel slightly to the left to get the car to go straight I noticed nothing out of the ordinary. Although I didn't exceed about 35 MPH or do any aggressive turning, the test drive was enough to suggest that the front end is very well behaved and far tighter now. I can't wait to get the car aligned so I can do a full evaluation.

One thing I forgot to mention earlier: when I pulled the front tires off the car originally in prep for the overhaul I noticed what I considered to be above average wear on the inner portion of the tread. Since camber is more or less fixed I know this wear is not due to excessive camber. More likely, I think, is that the slop in the ball joints on both the control arms and tie rods caused excessive toe (not sure in what direction...perhaps both, which might explain the sloppiness at 80+ MPH). Indeed, the factory specifications for toe on most BMWs is excessively positive in my opinion, so when it comes time to align the car I plan to shoot for zero toe. That may make the car a bit more skittish at high speed but I think the improvement in tire wear will more than offset that potential downside.

When I returned from the two mile jaunt I put the car back in the garage for an inspection. When that revealed nothing of consequence I pulled all the wheels to complete the brake fluid flush and was pleasantly surprised to find the fluid, particularly that exiting the rear calipers, in remarkably good shape for its age. It certainly wasn't as dark as the fluid shown on my Brake Flush DIY. I'm not sure why. The TYP200 fluid may just be better / more resilient than the stuff BMW sells and the dealer technicians use.

I had plans to do an oil service, detail the interior and exterior, and clean up the garage as well today but I ran out of time so those items are on the agenda for tomorrow. Aside from the alignment, which I have scheduled with Don for this week, the front suspension overhaul project is a wrap. Thanks to everyone who wrote in over the last two months with well wishes and tips.

Mileage: 222602