Maybe the SCIENCE guys can help in interpreting these specs?
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One thing I've found out that is new is that the angle measurement on many mobile devices (e.g., iPads and iPhones) is the off-the-shelf ST Microelectronics L3G4200D (apparently rebranded the STMicroelectronics AGD1
2022 FP6AQ for Apple products).
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Do you know if Android devices also have that same gyro? If so, that MEMS chip will be the ticket to us figuring out the angle accuracy.
On the ST web site, they list the "resolution" as "lower than 0.01 dps/yHz for zero-rate level", which I'm not sure how to translate into degrees of accuracy.
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Another spec they use for the L3GD20H MEMS gyro is: plus or minus 2000/ plus or minus 245 full scale typ (degrees/s)
Do you SCIENCE guys know how to interpret those specs so that we can get an idea of the resolution of the chip in terms of degrees of accuracy?
Do the Android guys know if that chip is also in Android devices?
The old standard was always about +- 1 degree, when you had no other specs to go by. Enthusiast cars like the BMW have different needs for handling purposes.
That's not uncommon.
That doesn't sound right. 2 degrees should not cause early wear, so you really need to check the ride height. And recheck the camber.
Yes, caster will not cause wear.
That's not the reason for the order, but it's not important.
I hate to say this, but you can get pretty close just eyeballing toe and camber. Especially with camber, if you can't see any substantial lean, the camber is probably close enough that it won't cause tire wear. In a pinch, it works for toe, too.
It's not necessarily a repeatable test, though. The one time you do that, you might have gotten lucky.
They are expected to print out the readings, so it takes some effort to lie. I'm sure they usually find something, but that's only because cars do go out of alignment.
I'm pretty sure that none of the manufacturers expect techs to load a car before alignment anymore. The specs take into account average occupant weights.
And I doubt that it makes the least bit of difference.
You don't really learn that, except for each time you try it. You can get very different results on future attempts.
Oh. OK. You actually understand this stuff. Thanks for explaining that the thrust angle isn't necessarily the centerline, but, for our purposes, we'll assume they're one and the same.
We're delving off topic, but if you live in a wet or dusty clime, your brake fluid will "suck up" water and dust, which, on a 10-mile long mountain pass, might make a difference in not so good a way.
Even if it doesn't, the alcohol in the fluid will slowly erode your gaskets in your master cylinder (and slave cylinder if you have a hydraulic clutch).
It will likely still work all dusty, wet, and black; but it won't work as well if you live in the mountains.
What I am talking about is mostly that maintenance and repairs are different, and there are vehicles that require a lot of maintenance and if you don't do that maintenance you get repairs.
Maintenance you can do at your convenience in a heated or air-conditioned garage. Repairs are not so clean.
The Japanese cars... you don't do a lot of maintenance, instead you do a lot of repairs all at once. The BMW, you do a lot of maintenance.
I mean the big rubber hose going between the throttle body and the airflow sensor. It cracks and then the airflow data becomes invalid and the car starts running lean. You can patch the cracks with 3M weatherstripping adhesive for a while until after a while you can't.
The issue on this one is that the they are using that TO220 FET as a linear regulator to adjust the voltage on the motor, and it develops a lot of heat of course. In Germany it's not a problem, but in Florida it fails pretty promptly. There are a couple places that have retrofit ones with big heatsinks. There have been a couple people talking about making PWM retrofits but nobody has done it yet that I know.
If you are changing oil every 3,000 miles you shouldn't need to do any of this. Just swab it out when you cahnge.
Tried Formby's Furniture Refinisher or maybe just xylene on it to liquify the varnish and redistribute it?
This might be the same issue as the fan controller and the exterior rubber: stuff that works just fine in the German climate but doesn't do so well in places in the US.
If you keep changing the fluid, the rack seals don't fail. If you don't change the fluid, the rack seals will fail. Changing to viton isn't a bad idea at all, but constant maintenance reduces the need to do that.
I would tend to disagree, with a few exceptions like the cooling system which really IS shameful.
Okay, I was making the assumption of the manual transmission. Why would anyone get a BMW and then put a slushbox in it?
If you DO have a slushbox, regular fluid changes are even MORE important although not at as short intervals, because if you don't do it regularly while the transmission is young, you're going to get exactly into that situation when the transmission is old. (Note also that a fluid change is NOT the same as a complete flush.... the complete flush is a bad idea in any case... just drain what comes out and refill it. It won't change all the fluid in the case but that's okay because you're going to do it again soon enough anyway).
Agreed that if you're stuck with a high mileage automatic that has been abused in its youth by a lack of proper fluid changes that the best thing to do is just keep your fingers crossed and hope it doesn't fail. (Well, really the best thing to do is trade in the car before it does fail but that's another story).
This is a case of repairs vs. maintenance again.
Nope, I'm just a guy who likes to drive cars for a long time, and I like BMWs for the reason that if you do put the proper maintenance into them you can just keep driving and driving them. I just rolled over 360,000 mile on the E28 this week coming home from work and it's still almost new.
I don't claim to be intelligent, I just claim to be able to keep cars running. A good argument could be made that if I were intelligent I would have traded the E28 in twenty years ago and I wouldn't be driving the 2002 at all. Certainly my wife makes that argument often.
The Toyota spec for the front camber is -.6? to .9? which is exactly in the range you suggested.
The BMW rear camber E39 I6 and 540 models with "standard," "low slung sport" and "M-sport" suspensions spec is apparently -2 deg 10 minutes. The tolerance varies among options: either +/- 20 minutes or +/- 25 minutes of angle.
The M5 spec is -1 deg 50 minutes perhaps due to 275/35 section width tires vs 225/55 for I6 cars.
For the caster on the toyota of 1.7 to 3.2 degrees, I am not yet sure how to measure it for the Toyota but I won't have to bother for the bimmer because caster isn't adjustable.
For the camber of -.6 to .9 degrees for the Toyota, I think I'll use a magnetic base inclinometer such as the Husky 10-inch Home Depot electronic level.
I think I'll just set the toe to 1/16th of an inch less in the front tread (measured as close to centerline of the wheel as possible) than in the back tread to centerline of the vehicle.
That will give me a total toe of 1/8th inch on the Toyota. I'll use toe plates and a tape measure, I think.
True. But it would be free if I got lucky! :)
But if I align it first, it should be within spec, at least for what can be aligned, which is, for the toyota, front caster, camber, and toe, and for the bimmer, rear caster and toe and front toe.
The 500 pound loading on a bimmer is for a different purpose. You are supposed to put 100 pounds on the driver seat, 100 pounds on the passenger front seat, and 200 pounds evenly spaced on the rear bench and
100 pounds in the trunk.
That artificially "lowers" the car to a specific "ride height" which all BMW alignment specs are to.
There is much discussion of why BMW uses that artificial ride height to normalize all their specs, but it has absolutely nothing to do with the "typical" loading of a vehicle with a driver.
I mostly agree with you that when the tire shop torques *all* lug nuts and bolts to the same 100 foot pounds, it probably doesn't hurt anything. Nor if they fill up all tires to the same 40 psi, again, it won't kill anyone (even though BMW specifies different pressure for the front versus the rear).
That they pry off the BBS hubcaps with a screwdriver just breaks the plastic tabs. And that they don't remove all the old weights just makes them put more on each time (and increases the chances of an imbalance from a lost weight).
And that they don't mount the tire with the red or yellow dots to the valve stem or match mounting mark just means they'll use more weight than necessary.
That they don't even torque the bolts in a star pattern probably only makes the wheel slightly crooked.
So, I agree with you that the fact that no tire is ever mounted correctly isn't causing accidents left and right.
My first smoke test for a lean condition showed a crack on the *underside* of that large ribbed tube. A few years later, my second smoke test showed that the tubes sticking out had leaks.
It would have been cheaper to just replace the damn things, instead of doing all those expensive smoke tests, which was your point, I agree!
Maybe you can answer a question which has irked me for years. As you know, the AC/Heating system is "fully automatic" meaning it's not intended for manual control, so, the blower starts at whatever settting it wants to start at when you start the car, no matter what setting you left it at when you last shut down the car.
I *always* adjust that, either to *off* or to the midway position.
But what I always wondered was, if the blower is on at all, whether the full on, or midway position caused less stress on the FSU?
I'm guessing from something a guy named cn90 and jim cash wrote that I found by googling, that the midway position is least stressful for that TO220 FET (there are three of those MOSFETs aren't there?).
Which blower position do you think is least stressful on that MOSFET driver if the blower is on?
1 bar
5 bars
10 bars
I know when my FSU failed the first time, it was so hot I burned my hand trying to get it out of those Germanic clips. The second one failed without heat, as did the others (where they failed in a way that gave the AC/heater controls a mind of their own).
Nope. I didn't know about that trick. Maybe I'll try since it's just the varnish that is cracked.
The ABS "trifecta" failing on the E38, E39, and E46 is also shameful. So is the trunk wiring loom fraying on almost every vehicle. And the headlight adjusters crumbling on some of the models like mine.
I've had 3 brake line failures. All rear wheel and all on cars that had +20 years driving in salt. Had one a few months ago. They've all been on my "emergency" cars. I was very close to home every time, and I always have a working e-brake. In every instance the lines were heavily corroded salt corroded. The only maintenance I could have done to prevent it was to replace the lines, which I should have done.
Just anecdotal evidence, but brake line replacement seems to be much more common in the past 15 or so years. I had the lines of my 5 year old Buick corrode. I know others that had to replace them on 5 to 8 year old cars.
Either new snow removal materials are being used or the lines are thinner, or both. This suppoerts it
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Connecticut auto mechanics told the I-Team they are concerned over a recent rash of rust and they blamed the need for so many rust-related repairs on the way cities and towns in the state treat the roads during winter storms.
The I-Team heard it at the Vernon Collision Center where they said, "everything just seems to rust. Five or six years ago, we didn't do nearly as many brake lines as we're doing now."
It was the same story at the Canton Gulf, where the I-Team heard, "I've been here 35 years and in the last three or four years we've done more brake lines than I have in the first 30 years."
I think you have a misunderstanding of total toe. It is simply Right wheel toe plus Left wheel toe. I don't see why it needs to be measured, if you have set left and right, total toe is just the addition of the two angles. See the explanation on page two, in the verbiage below the top left figure. >
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All your draws use the centerline of your tire, which you can't physically do. I would use the outside of the wheel, however, when you get your adapter with laser built, the line will be further out from the wheel edge. Here's my vision. Feel from to make your own drawing, Paint wouldn't modify yours the way I wanted.
First of all, if you'd had a competent BMW mechanic, he would have replaced it before it failed.
Secondly, when it DID fail, he would have looked at that and at the hose underneath it as the first things that cause leaks into the throttle body.
Thirdly, if he didn't know any of these things, it should have taken him less than five minutes to find the leak with a can of starting fluid. There is ABSOLUTELY NO EXCUSE for someone to bring out the smoke machine for that sort of leak unless they are trying really hard to find ways to bill their customers for something.
This is an EXACT example of what I am talking about when I say that doing maintenance is cheaper than doing repairs.
If you have it on full, the transistor is completely turned on and so there is less heat being generated in that configuration. However, if you have to worry about what position of the heater puts less stress on it, something is wrong. Put a retrofit one in there and it won't fail.
ABS I don't know about... but everybody knows about the loom so everybody wraps it. If yours wasn't wrapped, it will fail.
Likewise the headlight assemblies can be replaced with European spec ones in some cases, which don't fail. It's only the wacky DOT ones for the American market that are an issue.
I just rolled over 360,000 miles on the new car this afternoon. Should have it at 400,000 before 2018 starts.
I think he's fighting with a cheap harbour freight tire changer now. If it's not him it's his identical twin brother (perhaps by a different mother) If not the same guy, their understanding of the principals is about the same level of non-existance.
Yes, it is an odd discussion and, because of that, one that I have been loath to become involved in. FWIW, back when I was doing wheel alignments, and lots of them, Toe was always designated as a 'linear measurement', usually in fractions of an inch for most of the vehicles that I worked on, and it was never an issue. The equipment I used, from the very basic to the most sophisticated computer types, had both linear and degree scales so the issue in this thread is really a non-runner. What's more, there always seemed to be some sort of conversion chart on hand, supplied by the equipment manufacturer, so there was never a need to deal with trig functions. Failing that, these days there are internet options of which I supplied the URL to one such in a past post.
This is dead wrong. Everyone knows that hack. It doesn't work for the E39. It might have worked for 1970's era cars, but not the E39. There just isn't any change in the engine speed no matter where or how or what you spray on the underside of the plenum. The leak is just too slight and the difference in engine speed too slight and the chance of getting the fuel from the plenum to the plugs too slight.
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