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Unread 12-19-2013, 10:50 AM
Fair!'s Avatar
Fair! Fair! is offline
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Join Date: Jul 2004
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Default Re: Vorshlag E38 740iL - Amy's G-ride

continued from above

One of the trickier steps is when you need get access to the 4 screws that secure ribbon display unit to the cluster. You can either 1) remove all of the analog gauge needles and yank off the black backing cover, then disassemble the entire cluster or 2) drill 4 holes through the cluster (under the black flap of the front cover) to gain access to the screws. We went with option 2 because removing all of the analog gauge needles means you have to send off the cluster to have each gauge recalibrated. More down time.

Drilling these holes is a royal PITA, and it is easy to damage the cluster if you are not super careful. Now I see why there are shops that specialize in this rework! Next time we do this job we might think twice about sending the cluster off and letting a pro do this work, who can calibrate and test everything. But being careful and working on his bench Kyle got this new ribbon unit swapped in, replaced the back-lighting bulbs (2 of the 3 were burned out - don't forget to order those!) and replaced the binnacle back in the car. Now everything works, there is no faded sections (burned out bulbs), and we can read every pixel on every LCD display good as new.

Warning: If you got anything from reading this, know that this job is best left to a professional. We would highly suggest taking the car to an experienced BMW shop, have them remove the binnacle, and send it off to another shop to have the ribbon display replaced. This is not an easy "DIY" kind of job, sorry. Having done it successfully now we think Kyle could do another ribbon display install the next time in about 2 hours, so at our normal $105/hour shop rate + the $11 kit from Newegg that might be more affordable than sending the entire unit off to have it done. It would definitely be less down time.

What To Do With This Radio/NAV Mess?

Recently Amy and I took the 740iL on a road trip where we put about 10 hours on the car over the course of a few days. We went from Dallas down to the hill country to tour some wineries (not my thing) and go climb Enchanted Rock (more my thing). Along the way we managed to find some really fun, curvy back country roads to drive on. The 740 did great and the extra damping and spring rate from the customized Bilstein PSS kit we built really worked. On this trip I did become very annoyed with the factory sound system and NAV unit, however, both of which are very dated (the car is approaching 13 years old).

I have to face it - this E38 7 series is now 2 generations behind the current 7 series (the E65/E66/E67/E68 generation was made from 2001–2008 and the F01/F02 goes from 2008–current), so the fact that the "widescreen" NAV screen in this 2001 model looks more like an Asteroids video game than what a current Sat NAV screen does shouldn't come as any surprise. The radio reception on this trip was exceptionally poor (and isn't great around town) and the navigation function is so terrible and out of date we just use our phones instead.

So we should just rip it out and replace it all with a modern in-dash NAV unit, right? Not so fast. Doing this means we lose the "on board computer" functions, which are all shown on the factory NAV screen. And the shape/size of these BMW audio components are funky, non-standard sizes, which is par for the course. So this puts me is a quandary.... what do we replace the factory radio/NAV system with, while we keep the data from the OBC?

I think the answer has something to do with the previous generation E38 radio + "MIDI" display units that came in earlier cars from this same model. I'm hoping someone reading this can send me a PM or reply with some good tech, because after pouring through E38 forums I've not found a good answer. It seems like people went out of their way to ditch the separate radio + MIDI displays to "upgrade" to this "widescreen" NAV unit from the 2001 740/750 and X5 that we have. I'm wanting to go the opposite way - get rid of the NAV unit and "downgrade" to the MIDI display and an aftermarket radio. Will the old MIDI display plug in and work without issue? Is this old radio/NAV unit worth anything to anyone? What is a good in-dash install kit that fits without looking trashy (so many aftermarket radios look like crap once installed in the funky BMW dash openings)

The rear speakers are all totally blown.. the cones are simply shredded. They make this horrible buzzing noise when there is any bass in the music coming through the speakers, so we normally just leave the radio off. It is just a terrible sound system at the moment and it all needs to be replaced. Such a nice, quiet car with no tunes to listen to is a real shame.

And just don't get me started on the "integrated phone" center console sliding armrest contraption. There is a large void under that worthless sliding armrest lid, too. I wish these cars just had a normal, flip-top lid and storage area in the center. Why did you have to make the E39 and E38 have such worthless center consoles, BMW? And the factory cup holders are junk, can't hold a 12 oz cup, and break when you look at them funny, so I will probably go with something like this.

So we have several things on the interior to work on...

Rear Suspension Refresh

Before we left for the road trip in October I had the guys stick a 17" BMW wheel and tire in the trunk, since this 740 didn't have the factory full sized spare or a jack in it anymore. I really would like to buy a spare M-parrellel 18" 7 series wheel for a spare, so if anyone has one that want to sell, please drop me a line! I'd prefer the rear 18x9.5" wheel and tire, and a 7 series jack would be nice to get, but I'll take the narrower front wheel as well.

Olof had told me that the rear suspension parts were in need of some maintenance a few months ago, but I put that off until we had more time to delve into this work. The rear tires that came on this car were crusty and old, so if they were wearing funny I wouldn't really mind replacing them. Sure enough, after our long road trip the insides of the rears were getting pretty thin (see above). "To the cords" thin, which was bound to happen with as wobbly as the rear bushings had gotten.

So I had Amy drive another of our vehicles for a few days while we inspected the rear suspension more closely on the lift and determined which parts we needed to replace. Olof tested each ball joint and bushing back there and 75% of the joints had some wiggle, so we just replaced everything. This way we'd have a totally refreshed front and rear suspension. It is only $400 or so for all of the parts you need and we got the new bits from Lemforder and Febi.

When all of the parts arrived Olof got to work and knocked out all of the rear suspension replacement work in 3:45 hours, on the same day (and in about the same time it took) that Kyle replaced the LCD ribbon display. The book calls for 8:30 hours for all of these rear parts but we've gotten good at this E38/39 suspension replacement work, with a number of custom made tools and lots of experience doing this work. We log all of our shop work on the MyShopAssist service tracking system now so there are no surprises or unlogged work, even on our own cars. This system is very slick and our techs can take pictures or videos and email them to the customer (from an iPad at each work station), and customers can log in remotely and see real time progress on their car.

All of the ball joints, arms and bushings are now new on the back of this car, so it can finally be aligned properly. On the front the only adjustment is to toe, but out back there is both toe and rear camber adjustment. Next we needed new rear tires and an alignment.

New Rear Tires + Alignment

Now that the rear suspension bits are all new we can get some fresh rear tires on it. I really wanted to pull the trigger and get some flashy 19" super deep Forgestar F14s for this car, but the budget just isn't there at the moment. This stinks, but its the reality of life - you can't always get every toy you want.

Instead we ordered a "temporary" pair of Sumitomo HTR III rear tires (see above) to match the same brand and model fronts we put on his car earlier in the year, after replacing the front suspension bits (see my earlier post). This model of tire is a little noisy and doesn't ride as well as higher end brands, but they hold air and have a 300 treadwear. And they are cheap. For now, with half a dozen other cars at home and too many of my own race car projects going on a the shop, I just need some tires that aren't corded on the 740.

The mounted 275/40/18 tire at left fits the 9.5" wide wheel much better than the 255/45/18, which is a bit stretched

While we were replacing the tires I did manage to upgrade the size by nearly an inch. See the OEM rear wheel and tire fitment is somewhat unusual, with a narrow 255/45/18 tire on a wide 18x9.5" wheel. That makes the tire stretch out significantly when mounted, and for a street-only tire set-up that allows for easy "curb rash" on the outer lips of the wheels. I was going to try to go with a 265 or 275mm wide tire, which should fit the 9.5" better than the stock size. So I started scouring the catalogs...

The new 275/40/18 in front is just a hair shorter than the dry-rotted and bald 255/45/18 OEM rear tire, behind it

First I noted that the stock rear tire height is 27.0" tall, and after some searching I found that there was a 275/40/18 available from a few decent tire brands that is very close in height (26.7" tall). This tire was within 1% of the factory height (therefore within 1% of speedometer calibration), so that is the best option for the factory rear wheel, in my opinion. Once this tire came in (after huge delays from UPS due to some ice storms across the country) and was mounted onto the 18x9.5" rear wheel it looked perfect, and actually did fit better than the stock size. I love it when a plan comes together.

Before and After alignment numbers - it all looks good now!

After the pair of 275/40/18 Sumitomo tires were mounted we hit the alignment rack to set the rear toe and camber. We took the E38 to our friends at Eurosport for the alignment, since we don't have a 4 wheel laser rack at our current facility (its on my Wish List for our next shop!). The 740 came out with these alignment specs above. We hadn't even tried to align it after doing all of the rear suspension work so they had to chase the rear camber and toe from "way out there" settings. They almost got the rear camber within factory specs, but as low as we have this car it was just a hair out. The toe is all cleaned up on both ends, of course, which should be a tire wear saver.

Now we should be free of the funky tire wear this car has had since we purchased it. After driving the car last night it feels great and there's no funny feeling to the rear suspension anymore. We've finally got the suspension fully sorted and repaired, everything is aligned, and the tires are all fresh. A big chunk of the long overdue maintenance work is done, like the rubber hoses and seals, and the LCD panel in the dash is finally fixed. We still have some car audio and NAV system improvements that are needed, and a few small paint repairs I would like to have completed for the car to be 100% perfect. That cup holder and rear center armrest both need to be repaired, too. Again, if anyone has a 7 series E38 full sized spare wheel and tire they'd like to sell please PM me.

Until next time, thanks for reading.

Last edited by Fair!; 12-19-2013 at 10:53 AM.