W126 steering geometry

[Llewelyn]

Anyone have the setting angles handy for the W126? Replaced the brake[1] rod joints, and that made the tracking a bit wrong, so I thought I'd check the caster/camber etc. before resetting the tracking.

[1] or whatever you want to call it. The one that goes backwards from the track arm to the body mount behind the front wheels

 

[spike60]

From Autodata for a 1989 300SE like mine;

Toe in 0 deg 25min +/- 10min
Camber 0 deg +10min/-20min
Castor 10 deg +/- 30min

No load, full tank. Hope this helps.

 

[Llewelyn]

Yes, it does. I did manage to find the figures, but good to have them confirmed.

Been messing with it this morning. Castor was way too low (about 8 degrees) on both sides, which I kind of suspected when changing the support rod mounts: I put them back how they came off but both were wound almost fully in.

left side has about 2° neg camber even with the adjustment fully in, so I suspect something is shagged

Got the castor about right on both sides, camber on right side is spot on. Now working on toe-in, anyone know if that figure (equates to about 2.6mm in rim-distance terms) is fgor one wheel or total?

If I'm measuring beteen rims, I'm measuring total and when the figures are given in mm that is generally what it means - however, reading the info I found about how to set the steering if you have MB's equipment, they have a cunning gadget that fits on the suspension and measures everything - but that it likely to measure one wheel at a time, which would make sense as an angle rather than a distance.

Then there's the ting about the spreader bar which I don't have which puts about 10kg force between the front of the tyres. However, some helpful chap did a youtube video where he fits that spreader while the car is on a fancy alignment rig, and it reduces the toe-in by about 0.8mm - so if I set it a touch more toed-in than spec, I reckon it'll be close.

since I don't have a fancy laser rig, I'm not going to get it accurate better than about half a degree anyway...

 

[spike60]

Toe in is given as 3mm+/-1 mm, I assume that would alter with different diameter wheels though I've never set by mm, only degrees.
Spreader bar load is stated as 100kg, not 10kg.

 

[Llewelyn]

The data I found suggests 100N, which is approx 10Kg expressed as weight. I daresay if you get the correct tool it's calibrated in N anyway.

Set the tracking using rather crude measurements to about 5mm toe in, which seems to be not far off, judging by lack of abnormal tyre wear so far (in about 80 miles). It needs fine tuning 'cos the steering wheel is very slightly off centre. I suspect it's going to prove to be slightly too much toe in.

Handling wise, it has better self-centering and straight line stability. Still going to have to look into the camber on the left front, which is sitting about 1.5 deg -ve now, with adjustment at the inner end of travel. I'm guessing some component is out of spec...