Alignment Guru's? Question on camber...
 

So I am behind on schedule (due to waiting for a different ball joint splitter) on replacing my 2008 E350's lower control arms which have COMPLETELY eaten my inside tire severely as seen at the bottom image. The lower control arm bushings are split and the new fresh ones will solve this.
Needless to say I can't take it to the alignment shop this weekend anymore due to time constraints so I am looking into doing a good enough alignment to get by.

My lower control arm bolts are not like my 124's that are eccentric, so I assume that because of this, camber is not adjustable? Or at least not without buying the camber bolt kit...

If I use the string method that I looked up online, I should be able to get the toe set correctly right?

Over the years I have read that MB alignment is all magic and only wizards can align them, but after googling more and more, I can't see how MB's are any different? Sure they use the spreader bar, but again, after research, I found that the spreader bar is actually used to simulate high speed (autobahn speeds) which I do not travel close to anyway, so it shouldn't even matter.

What do you aligment gurus think or advise?

http://www.w124-zone.com/downloads/p...spension/2.jpg

Find the time to take it in. They use lasers and computers that you do not have.

I've been aligning my all my cars for over 30 years using an inclinometer and tape measure with excellent results. My '88 190E 2.6 front alignment adjustments - eccentrics on the lower control arm mounts are just like my 1976 Cosworth Vega, so there's nothing special about the front, but the rear may be a different story. Alignment shops have great equipment, but the techs are clueless, and I have specific settings for all my cars that are different than the OE recommendations.

It sounds like your car is a so called "net build" i.e. there are no adjustments other than to install offset "crash bolts". My '91 MR2 is like that - no camber adjustment, but caster and toe are adjustable. The OE camber is minus one degree, which is okay, but I adjusted caster (adjustable length drag struts) to the maximum, equal on both sides, that was available within the adjustment range - about six degrees.

I adjusted my '88 190E 2.6 to maximum negative camber and postive caster equal on both sides, available with the adjustment range, which came out to minus 3/4 deg. camber and plus 10.5 deg. caster. I never used a spreader bar for the toe adjustment and shoot for total toe-in of about 1/32". I think the idea behind the spreader bar it to take up any play in the joints.

I recently had to replace the tie rods and center link due to joint wear. It took a few tries tweaking the tie rods to get the 1/32" total toe-in with the steering wheel dead centered driving down a road with minimum camber, and since all the joints were new, there was no play.

With the settings I use, wear across the treads is very even with no indication of any abnormal wear. Typically fronts wear more on the shoulders and rears more in the center, but 7.5K mile tire rotations evens it out over the life of the tires.

Duke

Where are you in socal? Do you offer your services for hire? Lol. I hate the caster settings on most cars.

That's more than just camber wear, you have lots of toe. And are possibly low on air. ( if the outer edge shows any wear )

If tires are wearing due to worn out suspension parts and suspension is non adjustable, changing then will bring everything back pretty close.

My lower control arm bushing was cracked right down the middle and there doesn't seem to be any slack anywhere else in the system. I believe that was the cause of all the wear. The rest of the tire was fine -- Everything but the inside had 7/32" life left! Quite a shame actually...
Since the camber/caster is non-adjustable, and I replace the lower control arm + ball joint...then the only other place that would make any changes must be spring sag only.

I ran out today and bought a Craftsman Digital level gauge. I plan to cut a straight 2x4 to the size of the rim and use that to measure the camber.

I don't quite understand caster quite yet on how to "check" it? Can anyone explain if there is a way I can measure it using the digital level gauge I got?

Even with the Romess ride height tools and an MB specific alignment rack 211s are among a group of chassis that are very hit and miss when it comes to alignments. Good tracking AND tire wear is not easy to achieve.

Caster. Think of a shopping cart wheel. It has heavy caster. When you reverse it turns around. Tracking? If that thing isnt "leaned back" far enough it is too responsive. The more its "leaned back" the more it pulls back into a straight line.

Please excuse my lack of words.

Another thing, once something goes, I replace the whole front end. Ball joints. Tie rods. etc. while one part is broke it stresses the others and they will go soon.

Idk your car so I cant be specific. But you get the idea.

I'm not 100% sure on your car but I guess it is the same for virtually every other one I've seen - you can measure castor by turning the wheels by 20 degrees from straight ahead one way and then 20 degrees the other - each time you measure the camber and then add the values to get the castor

I don't work on others cars. It's enough of a job to keep up with my own, and I'm not getting any younger.

Duke

Caster is the difference in camber readings at full right and left lock. It's actually an approximation, but a good one, and the key is to set both sides as equal as possible. I can interpolate my inclinometer to about 1/4 degree.

The car needs to be on a level surface, and most residential garage slabs will suffice.

Camber is measured by placing the inclinometer or whatever angle gage you are using against the wheel flange or tire with the wheels straight ahead.

Then you turn the wheel to full right lock and measure camber. Say it's minus five. Now turn the wheel to full left lock and you measure plus five.

Caster is +5 - (-5) = +10 deg.

It can be tricky getting the algebraic sign correct on a car with near zero caster, but it's easy on Mercs, since most have high positive caster, so you know it's not going to be minus 10.

Duke

So to clarify, its simply A - B where A and B are the camber readings at full lock?

I went into the WIS and the alignment spec shows:
Firstly whats the conversion to inches so I can get it right?
Secondly, what does that "at vehicle level" mean on the camber? If you have the front of the vehicle on a ramp or something? Would I just use the +0.2deg, or am I not understanding what it says?

I understand that since my camber+caster are not adjustable -- I just want to check my numbers to take note and to see if anything else could be worn. I believe my issues before were completely bushing related...here's a pic of the bad bushings:
http://w124-zone.com/downloads/photo...nsion/lca1.jpg
http://w124-zone.com/downloads/photo...nsion/lca2.jpg

Thanks for the help so far guys!

I use a big bar and pry on stuff to check for play/wear. Lift up on the tire. Turn the wheel. Etc.

Front end work can be an art in diagnosis.

to understand caster, look at the front end of a motorcycle, the triple tree is at a forward angle, meaning if 90 is dead straight upwards, the angle of the triple forks intersects the vertical and places itself ahead of the perpendicular.

This provides the stability, the more the angle the higher the caster. To measure it you need a 90 degree point of reference of the spindle (or ball joint), ideally done with a jig that mounts to a solid area of the balljoint housing, e.g. the W124 FSM describes a tool that hangs from the ball joint clamping bolt, the little divot on the bolt ends is provided just for that. It has a string that goes across a scale to indicate caster degrees

In cars where the joint is hidden or unreachable reliably then you can measure with the camber difference.

If you have some slop somewhere in the spindle axis like worn arm bushings, worn ball joints or something that can throw it off - your measurement will be cuckoo.

your design is fixed camber/caster - your bushing is shot, your tire is shot from the inside, you have found your fault already.

MB springs are not that poor that they will sag at young age, I had similar wear on my W124 - the fault was ball joints, they were a bit way to sloppy for any standard.