Pagoda SL Group
W113 Pagoda SL Group => General Discussion => Topic started by: bpossel on August 06, 2005, 12:20:26
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Hi All!
I removed the spring nuts (cheater) this morning that I mentioned on an earlier post. Turns out there was only one of these cheaters, on the left side front spring. Drove the car to let everything settle....
Note: I have replaced my rear upper spring pads; center rear mount; and have new bilstein shocks.
Here are my current measurements (from center of wheel cover star to lowest point on my fenders:
Left Front = 14.5 inches
Right Front = 15.5 inches[:0]
Left Rear = 14.25 inches
Right Rear = 14.5 inches
Before I do anything else, any suggestions on next steps to try and reduce the height of the right front by 1 inch? Do I adjust the spring cup on the left rear?
:) Thanks for your comments!
Bob
bpossel
Memphis, TN.
1971 280SL
1997 E320
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You can just take the Mother-In-Law for a Ballast ride when using the car..Pleasure Cruise..:)
Your front lean is typical driver side spring fatique from many miles of driver only weight. That is why they had the spring helper on that side.
Many cures , from spring change to J Villers O rings/spacers.. Think you would be better getting the left back up to the right instead of lowering the right to even out with the worn left ..
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This would be a good time to collect information about ride heights.
My 230SL, Koni adjustable in front, old Bilsteins in the rear, custom srpings in front, stock in rear:
Left Front = 13.25 inches
Right Front = 13.00 inches
Left Rear = 13.50 inches
Right Rear = 13.50 inches
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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Wheel axle C/L reference is being used here for comparison and it is a good measure tecnique as it cancels out tire sizings, but what you realy want to look at is the difference in measure between the front control arm pivot points in Curb condition. This is the ideal heigth as it takes all other alignmnet geometrics into
consideration . The 113 spec here is 88mm , +5/-10, and the main concern for front axle lateral level should show no more than 5mm differential, r/l. This is where the spring rubbers trim specs are employed.
These specs effect turning geometrics and pivot specs , so they are a better reference for overall suspension handeling/performance.
All these specs are in the Data section of BBB chassis alignment sector.
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Using the star to fender technique, mine currently are:
LF -- 13.75 (read 13 3/4).
RF -- 13.75
LR -- 13.75
RR -- 13.75
Give or take a 16th of an inch since I was freehanding it. I was surprised at the evenness...
New Bilsteins, engine & subframe mounts. Original springs.
James
63 230SL
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Arthur ... I am all for better. What are the control arm pivot points at curb condition? From the lower outside trunion to inside upper trunion pivots? 88mm is about 3.5 inches. If that is measuring from the lower control arm to the floor, that would just measuring tire effect.
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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I would think that the condition of sub frame and rear axel mounts would have a big effect on ride height :?:
Mike Halleck
Chesterfield Mi
71 280SL
68 250SL (parts car)
94 E320 Coupe
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quote:
Originally posted by norton
I would think that the condition of sub frame and rear axel mounts would have a big effect on ride height :?:
Mike Halleck
Chesterfield Mi
71 280SL
68 250SL (parts car)
94 E320 Coupe
Most certainly.. any part that is worn enough to change the chassis geometics has an effect on spec measures.
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quote:
Originally posted by JimVillers
Arthur ... I am all for better. What are the control arm pivot points at curb condition? From the lower outside trunion to inside upper trunion pivots? 88mm is about 3.5 inches. If that is measuring from the lower control arm to the floor, that would just measuring tire effect.
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
Jim
This one is a little tricky to explain [ for me , not that it is tricky geometry] ..
I will try a comparison approach to a Right Triangle:
The thing that is getting measured is the angle slope of the lower control arm. This is done not from the floor as reference , but from the trunion/knuckle bolt C/L .
With the car on a level surface: Imagine a line going from the c/l
of the left trun/knuckle bolt [that goes through the lower control arm] going over to the right trun bolt c/l... so, this line is connecting the two bolts c/l.. right to left sides , full width of the front end...OK?
Now , the inner pivot of the same control arms [ that is bolted to the cross sub frame] is the measure point . If one measures down from that control arm inner pivot point c/l down to the imaginary line , the distance should be spec for that chassis [ according to Benz Data]
So , you can see that each sides measure forms a right triangle,
with the spec measure being the height side of the right triangle
[ side A]..the hypotenuse being the control arm. { side C ]
If both sides [ right/left]have the same spec at this measure , then you know the slope angle of the control arms are the same and the suspension is in spec. Changing spring, rubber , ect changes the control arms slope/ , along with the hiegth of the measure spec.
I made a simple tool for this measure and I think it is here or over mercedesShop somewhere in the archieves with the others .. been a long time ...
The trick here is to bounce the car a few times to let it settle out and load the car to your normal load .. It is all in the BBB somewhere , with specs for both curb and test load conditions..
..prob clear as mud .. I am sure someone with tech writing skills beyond mine could clean it up.
PS.
Seeing that you have just done some experimenting with different springs and konis up front , I would certainly check this measure to see how it compares to a Factory 113 spec , just out of curiosity...
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Arthur .... Let me try to simplify. On a level floor, the difference between the height from the floor of the inner A-arm pivot center and the height from the floor of the outer A-arm pivot center is the difference in measure between the front control arm pivot points in Curb condition that is shown in the technical data manual.
Expressed another way, if I make a cardboard right angle triangle with the hypotenuse the length of the lower A-arm and the short side 3.5 inches, it should fit square (level) under the A-arm.
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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Actually I think Arthur has explained it fairly well. Now that I look at it, this is the same way M-B spec'd out ride height on the later cars (116-123 etc) also. I usually measure from the floor up to the center points of the pivots and subtract the measurements to get a reading. The product of that calculation should be 88mm + or - 15 mm for the 113 chassis as Arthur points out. Using my floor up method has been fairly accurate for me in the past. Provided you are in this range, you should have no problem being able to get the alignment with spec.
Every spacer, mount, etc on the car affects this spec.
Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex
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Yes , you guys have it .. I don't mention measure from the floor cuz my Barn had wooden floors , so I never had that luxury. So , I made a tool that uses a right triangle as it base design.
The main 2 considerations are that the distance is within spec and that each side is within 5 mm of the other .
If measuring up from the floor , as long as the distance from the floor to the knuckle bolts c/l is the same on both sides , you are there .. [ assuming floor is level]..if not, a good trick is to use a few 9" or 12" flooring tiles under the offending/lower side until they are equal.
That takes the tire sizing/PSI out of the equation.
One will notice that Benz recommends lifting the bumper and taking one measure , then pushing down on bumper and taking another measure , devide by 2 to get the Mean.. but , you can get it settled with a few pumps and take one measure and get the same results.
The important part of this technique is that all the other measures come off the axle being in this position, so it is a very important consideration. When this is correct, the axle spindles are completely straight and parellel to the level line and only then is the camber added to the correct plane .. That is how the geometry design gets Correct.. Same as toe is set individually from chassis longtitude C/L , equal on each side of the line, rather than total measure.
Fussy ?? , yes .. but that is why I love these cars.. you can turn a screw or bolt and see the change/results of your adjustment..."tweaking" is a very satisfying gig for guys like us.
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:oops: With the discussion of height related to the control arms, does this mean that the king pin and the control arm outer upper and lower bushings also play a part?
In other words, I have replaced my right side king pin and outer (upper and lower) control arm bushings. I have not done the left side. Would this then be the cause of the right side being a bit higher than the left? :?:
Bob
bpossel
Memphis, TN.
1971 280SL
1997 E320
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My Star to fender lip measurements (John Olsen springs all around, new spring rubbers, 4 new stock Bilsteins) are: DSF, 14.5"; PSF, 14.75"; DSR, 15.5"; PSR, 15.75". -JP- '66 230SL, 5-spd, Kinder.
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Just for the catalogue, and for my own interest, mine are 14" all except the DR which is 13.5". Full tank of gas, all new rubber except rear subframe, new shocks (Bilstein, original springs. Sounds like I have a lowrider, but hey, it's a California car...
Greg
'64 230sl, fully sorted out...ooops, spoke too soon
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Originally posted by bpossel
:oops: With the discussion of height related to the control arms, does this mean that the king pin and the control arm outer upper and lower bushings also play a part?
In other words, I have replaced my right side king pin and outer (upper and lower) control arm bushings. I have not done the left side. Would this then be the cause of the right side being a bit higher than the left? :?:
Bob
While worn control arm pivot points will change the geometry slightly, I doubt you would see it in ride height difference.. lower left side on 113 is usually driver weight over the years ,, there is always a driver load .. on my car anyway ..:)
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I adjusted the ride height of my car with a jack this afternoon to 8.5 inches on the outside pivot and 12 inches on the inside pivot. That resulted in 14.75 inches from the center of the hubcap to the bottom of the fender. The measurements were the same on both sides. The appearance of my car looks high at that height.
Arthur .... What are the specifications to set the rear?
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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J
I don't follow you in that you adjusted the heigth with a jack???
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Arthur ... I used a jack under the center of the sway bar to raise the car until I had the specified 3.5 inches difference between the height of the inner and outer control arm pivots. It is really quite easy since the outer pivot stays at a constant height because the wheel is on the ground. After getting the correct measurements from the control arm, I measured it from the hubcap center to the lowest part of the fender.
I use the hubcap method because is easy and should be reasonably accurate. This procedure should be reproducible on any 113.
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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Oh, I see ..
You just wanted to see where a fender/axle c/l would be in reference to a correct spec. ride heigth control arm .
Don't forget , you are close to max at 3.5". The specs are from 78 to 93 mm with the +5/-10 allowed tol. included.. [ talking 3 to 3 2/3" approx.] You may want to do the allowable range for fender to c/l measure.
I thought you were going to see if the new suspension mod you did was in spec. I would be interested in those results.
Anyway , the rear is looking for 1 degree, 30min , +/- 30 min in curb load , positive camber..
You will note in the spec charts that curb and test loads do not vary camber changes with the heavy rate springs [ in comparison to standard springs].. this is a good testiment as to why regular springs usually result in sagging ass ends on 113s...
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Thanks Arthur ... I will set and measure hub to fender measurements for the 78 to 93mm differential measurements.
My front is currently too low at 13 inches (hub to fender) and I plan to raise it with the rubber spacers previously discussed. When I was at Blacklick, I had a lot of stuff in the trunk and the car looked level. With the trunk empty, the car looks very "aggressive" and drives superb.
I will probably aim at the lower end of the specification and then work on the rear. I am not sure that I have anything that will accurately measure to a half of a degree so I was thinking about setting the side chrome strip level (may or may not work (I can measure level accurately)). The rear has a visible positive camber so it may currently be close. It has the stock springs with new rubber bushings.
I'll let you know how the measurements turn out.
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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J.
There is a simple PVC homemade camber measure tool I listed somewhere in the Archieves..easy to make and will handily measure 30 min. increments...It is just a wheel offset fixture w/plum bob, but very accurate [ as all plumb bobs are.. :) ]
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Jim & Arthur - My 1969 Technical Data book shows the delta between the inner and outer pivots as 88mm plus/minus 15mm. 88-15=73 = about 2 7/8". I think I have mentioned this before - I like zero or a little bit of negative camber at the rear to reduce oversteer. I think this is even more important when you stiffen the front. As the front is stiffened traction increases at the front, dialing out some of the understeer M-B designed in. I think you need to balance that at the rear and reducing positive camber at the rear is an effective means to do so.
As I think about this project I have come to a conclusion - since the rear height is harder to adjust without altering the camber it might be better to get the rear set and then adjust the front to the desired height (hopefully it will be in the vehicle level adjustment range).
Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex
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I can not find those specs anywhere in my info. All 042/043 specs I have are 88mm curb, +5/-10.
On the rear neg camber , it is easy to change toward neg equally on both sides by using less shims on the comp. spring..
The main concern on the rear is the spring rate of soft springs allows too much neg with load.
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Arthur - I checked again. In fact, all models 108, 113 (including the 230 & 250), 114/115, etc. share the same 15mm plus/minus spec in the 1969 Tech Data book. I also found the same info in 40-0/8 of my Service Manual Passenger Cars Starting 1968. However, the 1959-67 Service Manual shows +5/-10. It appears they updated the spec over time.
Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex
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While on this subject. I am getting ready for round two of spring pad adjustment for the John Olson progressive rate springs that are in my 280SL. I would be nice to hear from some of the others who also purchase these springs and compare notes.
I hesitated to leave the car so my springs were installed in two installments. I took out 18 MM spring pads rear and repalced them with 24MM pads right height is about were it was a 25 1/4 to 26 inches from ground to top of wheel arch with a little positive that needs to be adjusted out . I read there is an ajustment for this at the rear. The front I took out 32.5 and replaced with 25MM the front sits at 24 inches from top fender lip to ground too low should be 25 1/4 to 26 inches. I am running 185 TR14 michelins tires.
I would appreciate any comments from other owners with the progressive rate springs from John olson. As I would like to get this problem behine me.
Thank You
Bob Geco
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I only have the earlier infos . My 043 specific also shows the 5/10.
.. but , that is not real important ..
Do you have info for camber w/heavy springs? ..Note there is no camber change between curb/test loads.
I personally think Bilsteins all around/ heavier springs in the rear with a zero camber and a matching front heigth w/early sway bar diameter would be fine.
I remember when these were new , there were some articles out where drivers claimed they would get the best perfomance from 042's by installing Konis in the back only and cranking them up a bit...
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Bob ... do your measurements from the center of the hubcap to the bottom of the fender (excludes all tire variables).
Vince/Arthur .... I finally have a data book ...... I found that the 113 had a harder spring option; front 113 321 05 04 which was 300 lb/in and rear 113 324 02 04 which was 380 lb/in. The height for the harder springs was lowered by 4 mm, min 2.9 inches to max 3.5 inches.
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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Yes , but only for curb load. , Note that the specs for test load are the same , regardless of spring. That 84mm is curb load w/standard shocks. The heavy version springs only came with the standard shocks [ non-gas]..That would account for the curb 4mm difference.
So, if one is using test load , the specs are the same .
That is why I mentioned I would prefer the rear heavy version spring
coupled with the Bilstein shocks.
...And I think that was about what was accomplished when guys went w/rear cranked Konis ..
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Arthur ... You are correct about the specification on "loaded height", I am still working on sorting out the "correct" look and stance of the car. I just need to work faster (I have been side tracked working on my daughter's Honda).
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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The camber data I have shows only data for the rear with "harder" springs, and it is the same as the standard springs.
I did see one tidbit that may be useful: A change of 2.5mm in the height of the spring pad results in a change of approx. 5mm in the delta of the control arm pivot points (dimension "a").
Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex
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They use the 2.5 mm /5mm "a" measure relation b/c the mounts come in 2.5 mm increments.
But if one is using spacer rings, the relation is simply 1/2.
Here are all
Front 2.5 results in change of 5mm 'a"
Rear 6mm results in change of 30' camber
3mm comp spring mount results in camber change of 30'
1 notch rotation of spring plate results in camber change of 10'
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Since Arthur mentioned the compensating spring mounts I thought I'd mention an anomaly I have run into ordering new ones for my project. M-B lists the two pads available by total height rather than by the thickness of the "flange". For example, they list the 110 329 01 85, 6mm pads as having a thickness of 21mm! Oddly, they are listing by the total height, even though part of the pad is down inside the spring and has no affect whatsoever on the ride height or camber. The 110 329 00 85, 3mm pads are listed as 18mm. Maybe this info will help someone avoid confusion when ordering theses parts.
Vince Canepa
1967 250SL
113.043-10-001543
568H Signal Red
116 Caviar MB-Tex
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Arthur ... I looked in the tech section and searched the archives for the PVC camber tool to set the rear ride height but could not find it. Could it be over on mercedesshop?
I did some measuring this afternoon to calibrate my hubcap to fender measure on the front:
(control arm delta => fender measure)
3 inches => 14 1/8 inches
3 1/4 inches => 14 3/8 inches
3 1/2 inches => 14 5/8 inches
It would be good if these measurements were verified by someone else on another car.
The 3 inch control arm delta looks about right for my car (unless I change the rear).
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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J
The tool is just a "C" jig that is made from some 1/2 pvc . 3 pieces and two elbows.... 2/4" pieces and 1/14" piece. [ $2/3]
Many use a level/board across the tire sidewall, but that is not accurate and the buldge of the tire , runout.etc , just doesn't make it .
so , if you make a stand-off, square 'C' fixture w/pvc , only the ends of the pvc will make contact with the rim of the wheel.This get the plumb out away from the car and tire where you can read it.
The long piece connects to the two shorts w/90 elbows and the overall tool length should be the same measure as the rim edge of the wheels the tool is to be used on. [ for 113, that is 14"]
Now. you drill a hole through the top pvc 4' pipe at 3" from the end that rest on rim. Then mark the bottom 4" piece at exactly 3" from that ones end. The top hole goes through the side of pvc c/l and the mark on the bottom one is on the side. Put a fishing line [mono] through the hole and hang a plumb bob on the line a couple of inches below the bottom piece, so the line pendulums across the lower marker.
The tool can be checked by holding it in your fist by the long pvc piece against any true perpendicular surface to make sure you plumb settles at exactly where your lower marker line is. [ I use a fine marker for this indexing mark] Once you have that established , you simply mark off a couple more index marks +/- from your known plumb mark [ two are enough] at exactly .2618" on each side of the original.. This is the inch measure for the tangent angle of 1 degree at 14" [ which is why you want the plumb line exactly 14' from the hanging hole to the index marker .. which is one of the reasons for the hole coming out the side of the pvc, etc]
I you want the tool for other measures , you have to find the tangent angle from a trig chart for different wheel rim size.
That's it .. grab the tool in your hand by the long pvc section , hold the two ends up against the rim edge , vertically, with just enough room for the Bob to swing freely past the index marks , and when it settles, read where it is in reference to the index markers on the botton leg of the tool. At zero camber , it will register plumb. At one index mark away from car , it will be 1 degree + camber. Toward the car , neg camber , etc...
The trick is to make sure the car itself is level from r/l before taking camber readings , as the tool plumb is in relation to level, as any plumb is...
As you can see , with a 1 degree index spacing increments of over 1/4 " , a 30' calibration is easily recognised..the tool is as accurate as your construction tolerences are.
Don't forget the wheel bearings adjust before testing camber specs.
Clear as mud ??
My scanner has crapped , so no pics.
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Here's a link to the old thread for the $5 camber tool http://sl113.org/forums/index.php?topic=2661,tool
Mike Halleck
Chesterfield Mi
71 280SL
68 250SL (parts car)
94 E320 Coupe
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Mike
That is it ..I see I doubled up the uprights for strength/stability.
I could not find it using the aearch..
How did you find it ??
Tnx
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Thanks Arthur ... I have the concept and will build one and play with it a little.
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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I remembered seeing it before and just searched for "camber tool"
Mike Halleck
Chesterfield Mi
71 280SL
68 250SL (parts car)
94 E320 Coupe
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Arthur .... I built a version of your camber tool today. Rather than PVC, I used left over copper fittings and pipe and soldered them together. After taking the measurements, looking up the sine to four decimal points in my 1962 edition of the CRC Tables (which haven't been used since calculators replaced slide rules), zeroing the tool on a "known" vertical (back door) and scribing degree marks with a digital caliper. The plum is an old bolt suspended by monofilament fishing line. Rather than a "C" frame, I built an "E" so that I could lengthen the plum line for "more accuracy". With that said, my measurements were:
Drivers rear: 3/4 degree, 13.625 inches (hubcap star to bottom of fender)
Passenger rear: 1 degree, 13.5 inches (hubcap star to bottom of fender)
Since the specification is 1.75 degrees +-0.5 degrees, the rear of my car is also too low.
I was surprised that the rear camber specifications are the same for the left and right wheels since the pivot is not in the center. I guess that is why they offer a half-degree variation.
Anyone else measure their rear camber and height?
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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<<I was surprised that the rear camber specifications are the same for the left and right wheels since the pivot is not in the center. I guess that is why they offer a half-degree variation.
>>>
Yes , .. That was a big problem with the earlier 121 chassis , as the step bearings and spring mount were equal distant from chassis C/L , but if you look closely at the 113 chassis geometry layout , you will see that they shifted the spring perches over to the right of C/L to help alleveiate the unequal right hand camber problem of the earlier swings....
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Arthur .... I learn something every day. The driver's perch is 424mm from the centerline while the passanger perch is 453mm for the centerline. An offset of about 15mm. The German elves must have stayed up late to figure that out.
Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
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Yes ,
438.5mm is mean, but they did not have that much room left on the chassis, but the right side camber is still different under load b/c the pivot is lower than the actual axle lateralC/L, so that makes up most of the difference.
The older swing had equal distance from chassis C/L on the spring perch/step bearing mounts , so the L/R springs were different , depending on model. Terrible set-up.
OK , Alex ..let's see .....I think I'll try "113 Chassis Geometry" for $600...:)