Axle alignment questions??

[erickmarciano]

Hi guys
The center carrier arm, the  spec of 158mm +/- 1 mm is this measured from the machined part (red line) or the cast part (grey line)?
When using the cooper tube tool:
Do we slack all the bolts of the 2 triangular mounts then we move that rod to adjust?
Once adjusted retighten the triangle plates?
Thanks   

[rgafitanu@gmail.com]

158 mm to the machined shaft. I didn't have to loosen the rear arm mounts, they have enough give to allow for adjustment.

[erickmarciano]

Just to be clear
The machine shaft is the red line I drew?
In the Bbb it shows the casting
Like this picture
Thank you

[rgafitanu@gmail.com]

If you blow up that picture you will see that the dimension line is aligned with the machined surface (yes, red arrow). It is an engineering no-no to dimension something from a cast non-straight surface and germans don't do that.

[erickmarciano]

Perfect I now see it.
last few question ( for now lol)
I dont quite get how to adjust the rod
Beetween 1 and 2 there is no adjustment.
By tighening between 1 and 2 we just compress the 2 rubbers.
1-  When changing rubbers how much to compress them?
2- to adjust rod we are supposed to slack 3 and turn 2. 2 is not accessible on the sl?

[rgafitanu@gmail.com]

I will refer to the numbers on the original drawing. If I remember correctly you slack lock nut 6 and you rotate rod 5 until you get it aligned. Then you tighten lock nut 6. I'm not sure if there is a torque spec for those 2 nuts that compress the rubbers. I used reasonable force, you don't want them to become loose in time and you don't want to squeeze the rubber out as well.

[mbzse]

.../...[is] there is a torque spec for those 2 nuts that compress the rubbers

No. You tighten the M10 nut on rod 5 until you bottom the threads. This compresses the rubber parts just right, for a correct fit.

Then, fit the lock nut back on there (or just use a Nyloc M10 nut).

The exchange of these two big rubber parts will in the majority of cases have the positive result, that the rear axle returns nicely to its correct center position (just like when the car left the factory). No need to adjust the length of the Panhard rod (rod 5).

[erickmarciano]

thanks guys
So once I bottom the m10 I slack the #6 nut then turn the bottomed out 10 to adjust the rod if needed?
thanks

[Dave H]

BBB states centering of the rear axle is achieved by screwing the rod in and out of the carrier .

[erickmarciano]

on the 280sl the welded nut in the middle of the rod is not accessible , I still don't get how to turn the rod..
from what I gather here the rubbers had to be super compressed since we are bottoming down the m10 nut.

[Dave H]

The rod is slotted for a screwdriver. Back rubbers and locknuts off so it turns easy.Mercedes think of everything.

[erickmarciano]

Yes but once I tighten  the rubbers  the rod will pull towards the rubbers and mess-up
The just adjusted rod??

[Dave H]

Do as MBZSE mentioned and fully compress the rubbers, measure ,see how the axle is centered.
If you find you need to move the axle 5mm to the left for example un compress the rubbers a bit so the rod turns ,screw the rod out 5mm,when you compress the rubbers again that extra 5mm of rod will push the axle 5mm to the left.
Screwing the rod in will pull the axle to the right .
Bit of trial and error, when it's right nip up the 2 lock nuts.

[erickmarciano]

Got it
Thanks
Do the wheels have to be on the floor?

[Dave H]

Way off the floor ,so you can measure with your check gauge and have room to work.

[erickmarciano]

finalizing the axle installation.
if the axle is hanging I can still adjust it with the cooper homemade tool? or car needs to be loaded?
thanks