How I adjusted the toe in / out, camber and caster on my W123 300D - Page 3 - PeachParts Mercedes-Benz Forum

Stretch · #31 02-20-2015, 02:19 AM

Quote:

Originally Posted by Junkman

The 126 FSM says that a change in camber causes a change in caster and vice versa. It also gives an approximate relative amount of the change. I've taken this to mean that one could anticipate the change when making the adjustment. (I have it on dropbox. Send me a pm if you want it.)

I had a McAlignment place give my 85SD back with both camber adjustments maxed out tipping the wheels to the passenger's side. The tech got frustrated making 1 adjustment and having it throw off the one he has just done. He wrote that "car couldn't be adjusted to spec". He apparently meant that HE couldn't adjust it.

I think that's probably quite common. The geometry is a pretty weird triangular configuration up front on a W123 / W126.

Lucas · #32 02-20-2015, 03:15 AM

Didn't you say making gaskets isn't worth the time? Just teasing. This is interesting. I saved it to read when I can focus better. Lol.

Stretch · #33 02-20-2015, 04:05 AM

Quote:

Originally Posted by Lucas

Didn't you say making gaskets isn't worth the time? Just teasing. This is interesting. I saved it to read when I can focus better. Lol.

You are quite correct - this is not the fastest way to get it done. But it is actually better than those silly laser guided machines. That you can do a much better job than those machines with string and a tape measure is very satisfying! (Albeit bloody fiddly long winded and at times tedious)

Zulfiqar · #34 02-20-2015, 10:44 AM

I had my W124 aligned at a shop where the tech was very eager to read the FSM copies I had for the car.

he picked up one point that almost all other descriptions throw out. - set toe to zero...

he was constantly adjusting the toe to zero anytime he was changing the control arm bolt settings, this was the control point for everything as due to the insane caster angle of these cars the wheel drops outwards when turned out (heavy camber change) and vice versa for inward.

I took my W210 to the same person (W210 is a bit similar to W123 setup but with less caster) - he did a good job on it too. He did keep the W124 data sheet that I printed and also asked for copies for the W210 spec sheet, his claim was that the sheet provides more information than the alignment rack manufacturer does in their cars listing.

The idea was to set toe as last adjustment - do the camber/caster bugaboo at zero toe - once everything is set dial in the toe (install spread bar or make your own or dial in a smidge more toe) - and the car will be in good alignment.

Lucas · #35 02-20-2015, 11:23 AM

Quote:

Originally Posted by Stretch

You are quite correct - this is not the fastest way to get it done. But it is actually better than those silly laser guided machines. That you can do a much better job than those machines with string and a tape measure is very satisfying! (Albeit bloody fiddly long winded and at times tedious)

Well that's how I feel about fuel pump gasket material.

This is cool because I've replaced my front end before and had a wild ride to the alignment shop.

And I'm somewhat of a doomsday prepper and like the idea of being able to do everything.

Maxbumpo · #36 03-20-2015, 01:43 PM

Resurrecting an old thread here, which I find very informative.

I'm very curious about the chassis level measurement tools in post #4. I'd love to hear more about how to make and use them.

Stretch · #37 03-22-2015, 03:05 PM

Quote:

Originally Posted by Maxbumpo

Resurrecting an old thread here, which I find very informative.

I'm very curious about the chassis level measurement tools in post #4. I'd love to hear more about how to make and use them.

I'll scrape something together for you in the future. I can't help at the moment as I'm a bit busy with other stuff - sorry - but essentially I did my best to replicate the tools in the FSM. If you study them closely and then look at the parts on the car you can kind of see where the parts are meant to be level. The car, however, has to be on a level bit of ground in the first place for the DIY tools I made to work...

...as you can see from the pictures they weren't especially difficult to make - just lumps of suitable lengths of wood and then threaded bars which could be adjusted to suit what I thought was meant to be measured (information gleaned from FSM).

I didn't expect anyone would want to do this part of the procedure so I skipped over the subject a bit when I started the thread all those years ago. So count yourself as one in a million!

BillGrissom · #38 03-22-2015, 10:02 PM

Good info. I have done alignments myself on my two 300D's and they go straight w/ hands off the wheel and no uneven tire wear. Toe-in is the most critical, and can be done w/ a tape measure aft-front distance. Easiest if your front tires have straight channels. Shoot for 1/8" toe-in, or 1/16" if you know the parts are all new and tight.

Camber is mostly a personal preference. I go for a slight lean-in at the tops. I place a carpenter's level against the bottom tire, held vertical (per bubble) and subtract difference in horizontal gap to top and bottom of wheel rim. Tuners go with extreme negative camber (lean in) for that Indy-car look. Helps w/ cornering, but wears the tires more.

I never touch caster, but would if I ever replaced the guide rod pivots. Caster is the "shopping-cart wheel" effect, that help the wheels follow the motion.

funola · #39 03-23-2015, 11:34 AM

Quote:

Originally Posted by Stretch

.............
To measure the front wheel toe in / out the FSM states that you need to use a spreader bar to apply a force of 110 to 120N. I have actually seen other values of this force quoted such as 90 to 110N in the W126 FSM. Anyway I found this to be difficult to achieve without the special tool (000 589 18 31 00) – but I think I've come up with a pretty good compromise. Essentially if it were a vertical force the spreading force would feel like a 9 - 12kg weight. I have no way of measuring this but have a gut feeling that my DIY clamping device when turned into a spreader bar provides sufficient force for this job. This is a compromise and I can't be sure that it is good enough but it is the best I've got. I propped my spreader bar up on blocks of wood and used yet more wood to help reach the span between the front wheels.
................

Stretch, did you buy a spreader bar? I found a youtube clip on one and looks like it is just a spring loaded telescoping bar. Do you know why a spreader bar is necessary to adjust toe-in? I never use one when adjusting toe-in in all my cars and never have uneven tire wear. If I were to improvise a spreader bar I'd be looking at a piece of wood for an English or Japanese long bow and adjust its weight with a bathroom scale.

Can you post a link of the FSM chapter with all the alignment info? I can't find it in my W123 FSM CD.

Maxbumpo · #40 03-23-2015, 03:09 PM

124 vs. 123: As I understand it, one should set the toe-in to zero, then set the camber (and caster) to the correct values, and then adjust the toe-in?

On a 123 car, there is only one inner bushing on the lower control arm. Adjusting the toe-in causes a change to the camber, so you kind of go back and forth on both those adjustments to get both values into spec. On a 124, there are two inner bushings. Would that eliminate the back & forth between camber and toe-in?

Stretch · #41 03-24-2015, 03:12 AM

Quote:

Originally Posted by funola

Stretch, did you buy a spreader bar? I found a youtube clip on one and looks like it is just a spring loaded telescoping bar. Do you know why a spreader bar is necessary to adjust toe-in? I never use one when adjusting toe-in in all my cars and never have uneven tire wear. If I were to improvise a spreader bar I'd be looking at a piece of wood for an English or Japanese long bow and adjust its weight with a bathroom scale.

Can you post a link of the FSM chapter with all the alignment info? I can't find it in my W123 FSM CD.

I used the data in the W126 FSM (probably now available on startekinfo I guess).

For the spreader bar I used a large one handed wood working clamp - you know the type that can be used to expand as well as clamp...

...I found that the applied load specified in the FSM is about the same load the sidewall of a tyre fitted to a 14 inch wheel flexes - I pushed the wheels apart (on the front) until I could see the side walls starting to deform as well as kind of guesstimating the applied load.

(Please note - I did this with the wheels on slip plates - this won't work with weight on ground because the wheels won't move so easily)

Quote:

Originally Posted by Maxbumpo

124 vs. 123: As I understand it, one should set the toe-in to zero, then set the camber (and caster) to the correct values, and then adjust the toe-in?

On a 123 car, there is only one inner bushing on the lower control arm. Adjusting the toe-in causes a change to the camber, so you kind of go back and forth on both those adjustments to get both values into spec. On a 124, there are two inner bushings. Would that eliminate the back & forth between camber and toe-in?

On the W123 the weird triangle effect (view suspension with bird's eye view) means adjustment of the camber (mostly done at LCA eccentric bolt) messes up the castor (which is mostly adjusted on the brake stay) and vice versa. The FSM says you can only set either castor or camber with the toe set to zero.

I was planning to adjust my W201 suspension but I ran out of time and needed a much flatter driveway to perform a four wheel alignment (back wheel adjustments spoiled the day); so I don't have much to say about that procedure.

funola · #42 07-20-2015, 09:16 AM

Quote:

Originally Posted by Stretch

Arrrrgggggh!

Given up!

The W201 needs a lot more attention on the rear end than the W123 - that multi-link suspension needs to be aligned as well as the front. On the W123 there isn't any adjustment so I was able to get away with quite a lot more on my uneven driveway.

I failed at more or less the fist hurdle - setting up a box around the car. I was trying to get the positions of the four corners (of my box of string) aligned parallel to the subframe mounts and the mounts for the lower control arms on the front =>

In principle "dropping" points onto the floor with the help of a plumb bob could be done to measure distances between these positions and the (string) box reference points. Unfortunately my driveway isn't level enough for this...

...oh for a nice big flat and level expanse of concrete!

I've had to suck up my pride and dig 80 euro's out of my wallet for the local tyre shop to have a go at it. Frankly I'm not HP.

Digging up your old thread. Here are some great posts from other forums on DIY alignment with some great ideas in getting leveled on an uneven driveway.

TheSamba.com :: View topic - DIY Wheel Alignment

VWVortex.com - Tired of paying $’s to align your bucket? Alignment DIY Inside!!

I need to check and set camber and toe on my VW (after removing both front struts). I am looking at some of the following tools to make angle measurements easier.

This Johnson $40 digital level can be calibrated by flipping it 180 degrees. +/- 0.1 degree accuracy.
Johnson 10 in. Electronic Digital Torpedo Level-1457-1000 - The Home Depot

This HF one needs to be placed on a flat level surface to calibrate it. +/- 0.3 degree accuracy.
Digital Angle Finder / Angle Gauge

I also downloaded these 2 free apps on my Android phone and will be checking out their accuracy. First look = promising.
https://play.google.com/store/apps/details?id=com.plaincode.clinometer&hl=en

https://play.google.com/store/apps/details?id=bz.ktk.bubble&hl=en

slowrider240D · #43 08-22-2020, 11:50 AM

Should you not want to do the math, I calculated the following. I use these calculations with optical systems I have made to align my vehicles. I suggest the use of a laser pointer (sufficiently mounted and referenced to level) to do determine level and parallel for the wheel pads Thank you for having the patience and taking the time to post Stretch

When you consider that 0.002 inches (roughly 0.5 mm) is one minute of angle, PAY ATTENTION TO STRETCHE's admonition about bearing adjustment and wheel straightness. It makes a huge difference

14 inch wheel Inches mm
Diameter circle 14 355.60000
Circumference 43.982297150 1117.15035
1 degree (Circ/360) 0.122173048 3.10320
1 minute (Deg/60) 0.002036217 0.05172
1 second Min/60) 0.000033937 0.00086

15 inch wheel Inches mm
Diameter circle 15 381.00000
Circumference 47.123889804 1196.94680
1 degree (Circ/360) 0.130899694 3.32485
1 minute (Deg/60) 0.002181662 0.05541
1 second Min/60) 0.000036361 0.00092