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-   -   MB DOC, Steve B, Larry Bible... Tell me what these alignment data mean (http://www.peachparts.com/shopforum/showthread.php?t=213032)

lizem100 02-07-2008 12:29 PM

MB DOC, Steve B, Larry Bible... Tell me what these alignment data mean
 
Just replaced upper control arms and lower struts on 2001 S430. Got an alignment and a "camber/caster bolt kit" was installed
ones digit will represent degrees and tenths minutes
Rear Axle
camber
L -1.4 (before) to -1.37 (after) range should be -1.03 +/- .30
R 1.32 to 1.36
Is rear axle camber not adjustable because they are out of spec after alignment?
toe
total .25 corrected to .46 range .43 +/- .07
L .16 to .22
R .09 to .24 range .22 +/- .04
geometrical driving axis
.03 to -.01 range 0 +/- .15
Front Axle
camber
L -.59 to - .56 range -.46 +/- .20
R -1.00 to -1.02 same range
Why are the number not exactly -.46? Is the adjustment not fine enough?
caster
L 7.58 to 8.39 range 8.55 +/- .30
R 8.11 to 9.06
track diff angle
R wheel lock - 1.45 to -1.56 range -1.34 +/- .30
L wheel lock -1.32 to - 1.38
toe
unpressed .57 to .18 no range given
pressed
total .59 to .18 range .20 +/- .10
L .31 to .09 range .10 +/- .05
R .27 to .09
Any comments? Was the job well done? Why list tire pressures/ tread depth re alignment? They even listed tire size and brand- perhaps for analysis of ride quality.

mbdoc 02-07-2008 02:37 PM

Looks like the very first step was missed!
First step is the measure & calibrate the ride height in the air-matic system.

The only glaring issue is side to side camber.

ILUVMILS 02-07-2008 09:01 PM

Quote:

Originally Posted by M.B.DOC (Post 1756046)
Looks like the very first step was missed!
First step is the measure & calibrate the ride height in the air-matic system.

The only glaring issue is side to side camber.

Yeah, I agree. The only way to determine the optimum alignment angles is to measure ride height first. But the numbers still look good.

As far as the side-to-side camber goes, it looks like lizem100 forgot to put the "-minus" sign in front of the R/R number.


Quote:

Originally Posted by lizem100 (Post 1755919)
Is rear axle camber not adjustable because they are out of spec after alignment?

Why are the number not exactly -.46? Is the adjustment not fine enough?
caster

Any comments? Was the job well done? Why list tire pressures/ tread depth re alignment? They even listed tire size and brand- perhaps for analysis of ride quality.


Rear camber isn't adjustable, but don't worry about it. Adjusting the toe-in results in slight changes in camber, and you're barely out of spec. Like 'Doc says, the omission of the ride height check could result in specs' that are slightly off, but the numbers still look OK.

As far as fine adjustments are concerned, the "camber/caster bolt kit" only allows for finite adjustments. The adjustments can't be tweaked to perfection. MB has used this system since the early '90's on most models. It looks like your alignment shop installed both front caster bolts and possibly the L/F camber bolt.

There are two reasons for the additional tire information, and other information on the print-out sheet. First, depending on the alignment equipment, this information may be required to procede to the actual measurement/adjustment program. Second, it's a liability issue.

lizem100 02-10-2008 10:47 AM

ride height data
 
I was not sure if it was important but here are the data from the MB chassis alignment test sheet
front axle level for driving 10mm/6.9 as before, target, and after
rear axle 10mm/-.6 before,target, after
They both look to be in spec
What is the RR number that I forgot to put a minus sign with? I will double check the sheet if you tell me.

stevebfl 02-10-2008 11:47 AM

Is there a problem?

The reason the front camber can't be -.46 is that there really is no adjustment. The use of bolt kits gives either a plus or minus correction of a fixed amount... about .3/.4 degrees.

The difference in camber in the front could be intended to offset a drift to the right. All of these measurements are significantly changed by ride height as stated above and won't be right if there are differences in height.

lizem100 02-11-2008 02:16 PM

Car had no symptoms
 
Car was not pulling in any direction. It had 98K miles and I had just changed upper control arms and lower struts.
I asked on the forum if I should get an alignment and was told to do so.
Is the ride height data what everyone wanted before commenting?
ILUVMILS-what is the r-r data I may have forgotten to put a - sign in? I will double check

ILUVMILS 02-11-2008 07:29 PM

Quote:

Originally Posted by lizem100 (Post 1755919)
Rear Axle
camber
L -1.4 (before) to -1.37 (after) range should be -1.03 +/- .30
R 1.32 to 1.36

This one.

lizem100 02-13-2008 12:01 AM

R rear camber should be negative
 
I checked and the camber is negative.

So In summary is the alignment ok and do you have enough data to decide now?
Thanks.

matsalleh76 05-23-2009 05:33 AM

201 Alignment procedure.......
 
Last time we had the alignment done on the 2.3-16 the shop doing the laser alignment ended up with all settings with in spec but had to do each over several times because of the interrelated effect each has on the other. They were not pleased with the time it took but stuck to their quoted price.

I would like to save a little heart ache this time around and assume that there is a recommended procedure: first do "X", then do "Y", then finally set "Z", but I have not been able to find anything. There is nothing in the factory manuals, or in searches of Tech sites such as this.

Any advise on the proper procedure and tips on same will be greatly appreciated.

Thanks & regards,
bobf.


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