Using weights to preload suspension: no exception for E39 Sport Package

The BMW TIS has a table--explained here http://www.bmwmotorsports.org/BMW_docs/x5align.pdf
--that provides stock ride heights. According to Jim Cash, “measurement is to be done with car in normal loaded condition.” In other words, ride height is measured in what the TIS calls “normal position,” with weights added to the seats and trunk.
http://www.bimmerfest.com/forums/sho...5&postcount=14
The exceptions to the rule of using weights mentioned in TIS and BMW alignment documents are M-cars, i.e. the e39 M3 in this: 32 00 Wheel Alignment - Normal Position / Inspection Conditions E36 / E38 / E39 http://ebookbrowse.com/td-wheel-alig...pdf-d291668225
Nonetheless, there is a broader claim, heard occasionally on e39 forums, that all sport models are an exception to the rule for using weights to pre-load suspensions.
http://forums.bimmerforums.com/forum...5&postcount=61
This appears to be a misinterpretation of the table in the BMW TIS that classifies suspension types.
http://www.bimmerfest.com/forums/sho...7&postcount=15
32 00 Wheel Alignment - Normal Position / Inspection Conditions E36 / E38 / E39
• Low Slung Sports Suspension - This is used on vehicle with Sports Package Option.
• M Sports Package - Used on Motorsport vehicles or those with M Package Option.
This table creates confusion by mishandling the exception to the pattern, the 2003 540 Sport. The Low Slung Sports suspension is indeed for all sport package e39s, but not that one. The M-sport suspension type is for all M-model cars; however, “or M-sport suspension” pertains *only* to the 2003 540. This is confusing for owners of e39s with M-sport package and/or M-sport suspension. Worse, the 2003 540 Sport, commonly designated M-Sport II to distinguish it from the preceding M-Sport e39s, belongs to the suspension class M-Sport.
This agrees with evidence from owners: 2003 540 owners note that their struts have an M on them, which is the way this suspension type is identified. The M5 ride height is known to be higher than for the 540, which agrees with the table. E39 M5 owners do not use weights: M5board gurus agree that the instruction, “tighten in normal position,” refers not to weights but to having the car on the ground, or the suspension otherwise compressed.
Like many, I hesitate to use weights, given the time and effort involved with ten 50lb sandbags. But weights are called for when torque data say, “tighten in normal position” for replacing control arms, thrust arms, and sway bar brackets. The main reason for weights is that the alignment specs are not correct otherwise: http://www.bimmerfest.com/forums/sho...5&postcount=37
Another reason: weights are needed to do the ride height specs by the book. Why lower accuracy when the ride height tolerance for a 540 is only +/- 10mm? Especially given the numerous sources of error: settling of a new suspension, thicker new mounts; level ground; measurement methods--a carpenter’s square (cn90 front suspension) vs. a tape measure along a non-perpendicular line to the wheel edge (BeisianSystems); when using the alternate method to normal position–-jacking up the hub to the known, measured, height—you must apply a lot of force, not all of it vertical, to a floppy object; or, as the BeisianSystems Thrust Arm procedure puts it, “Optimal placement of lift at wheel carrier is unclear.”
This post is more of a clarification than a question._a_

This was discussed extensively many many times before.

As is true for anything else in life, there are 2 approaches one can take for any issues:
a- Blindly believe the book.
b- Use one's judgment and modify the procedures as one see fit.

I belong to the latter group.

are 10 years out of production! That which can be done has, there is no sense to re-invent the wheel

I think the O.P. just wanted to say how "good" the factory manual is.

Typing /weight into the bestlinks nets me these (see bold red below):
- Which of the dozen alignment specs are adjustable on the BMW E39 (1) (pdf) & cn90's front (1) (2) and rear (1) wheel alignment DIYs & how to keep the steering wheel (SW) straight during home alignment (1) (2) & what tools measure rear camber at home (1) (2) and what tools measure front/rear toe at home (1) & what tools lock the steering wheel & brake pedal at home (1) & the theory of alignment with weights (1) or without adding weight (1) (2) (3) & philosophically why most people prefer to let a professional alignment shop align their suspension (1) & what expensive equipment is used at the stealer to align your suspension (1) (pdf) & Internet references for how to DIY caster, camber & toe at home (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (36) (37) (38) (39)

In order to make progress, I'll cross reference this thread to the theory of adding weights thread above (note that I try to make ONE thread canonical, so that at least one thread is one-stop shopping). (doesn't always work though)

The Bentley's manual states that weighting is required for all suspension adjustments. It gives a seperate set of alignment specs that only apply to the 2003 M-tech model.

The BMW alignment spec is based on the income, and number of kids of the buyers that come to their showroom.

Originally Posted by cn90

The BMW alignment spec is based on the income, and number of kids of the buyers that come to their showroom.

You know, because we just weight it with bags of money while doing the alignment.

chiefwej, thank you for providing the alignment data for the 540 from Bentley. Bentley also includes ride height info, just before the section on the front suspension. To summarize my above post: For Sport package owners puzzled by seeing two suspension classes, Sport and M-Sport, in Bentley or TIS, each sounding like it's for their car--not to worry, the latter is only for the 2003 540’s M-Sport II suspension. A few posters, citing this table, have said that the exception to the rule for adding weights is for all Sport package e39s. The exception is really just for the M3. To the cross-linked thread about reasons for using weights, I add this rebuttal of the “weight it like you drive it” theory, by Roundel consultant, Brett Anderson (koalamotorsports): “Most people... come up with a line like "well, I want optimum alignment settings on the car with just me in it, because that's how I drive it most of the time...." Fact is, you couldn't ask for a more screwed up alignment.”
http://www.unofficialbmw.com/all/sus...ment_info.html

Sorry to burst your bubble, but Brett Anderson is wrong when he makes that statement.

The bottom line is:
- It is fine to follow the book (extra weights)
- But it is also fine to use no extra weights.

Just do an alignment with and w/o weights, and you will discover that extra weights change very very very very very very little, if any, of the alignment specs. This has been discussed extensively in many different BMW forums.

If you fix enough cars, from Honda to Volvo to Toyota, virtually all of them specify alignment with no extra weights (just a full tank of gas).

This weight thingy is a waste of time because adding a driver changes virtually nothing (in terms of camber, toe-in).

I just align my E39 with full gas tank, zero issues, car tracks straight and absolutely no problem with tire wear.

i dont preload my suspension with added weight because its unrealistic. NOt once have i ever had a full trunk plus 5 people in the car.

I preload the bushings under the cars own weight. The most added weight it sees 99% of the time is the driver and only the driver. My tires wear just fine.

After doing a keyword search for “alignment weights,” this is what I found:
When people decide not to use weights, the reason they give, as a rule, is the passenger weight explanation.
Adding weights changes rear camber significantly--as much as 1 degree.
http://www.bimmerfest.com/forums/sho...8&postcount=37
http://www.bimmerfest.com/forums/sho...8&postcount=33
CN90 alone claims categorically that adding weights makes no difference to alignment: i.e. the above post or this: “I did the measurement with and w/o weights, there is virtually no difference in the spec's.” http://www.bimmerfest.com/forums/sho...61&postcount=5
Support for using weights:
http://www.bimmerfest.com/forums/sho...12&postcount=3
http://www.bimmerfest.com/forums/sho...9&postcount=42
A risk to owners of high rear camber and excessive tire wear, as shops tend to be unaware of the e39’s requirement for weights:
http://www.bimmerfest.com/forums/sho...22&postcount=2
http://www.bimmerfest.com/forums/sho...61&postcount=4
Explanations for using weights other than passenger weight: http://www.bimmerfest.com/forums/sho...08&postcount=5
http://www.bimmerfest.com/forums/sho...08&postcount=8
http://www.bimmerfest.com/forums/sho...40&postcount=4

After dealing with 15 alignments with weights and w/o weights all i can say is to do alignment where people know how to do it for BMW
Weight is not critical for alignment but very critical when you do suspension work
Make sure you preload your suspension ( normal position is just fine ) for any bushing changes

And when you lower your suspension dont forget to re-preload the bushings at the new neutral height