I have too much slack ....although I adjusted the box 3 times already ... with not much success.
The rest of the steering connections have no slack as far as I can see.. So it is the steering box.

As this is one of the early gear boxes (I believe it is the Gen1 gear box with the straight arm) there is only a limited amount of wear that can be compensated.

Now I bought a used late Gen3 W126 gear box because this one has the larger compensation option with a better chance of success.


Now my many questions -to those who know- about the preparation of this 'new' box for install in my 1984 500SEL

1. Do I need to swap the straight arm from the old box to the new box? Or can I use the new arm?
In case of the arm swap: That arm is sitting quite tight on the splices. Is there a good puller that works here?
2. With the new box on the bench I feel play in the arm, as soon as the arm is leaving the Center area.
But there is no obvious play in the Center area.
Is that play in the periphery acceptable or would you pre-adjust the box before installation? Any protocol for the prep on the bench while the box is easily accessible?

Best, Martin

Anyone with some knowledge of the W126 steering gear boxes?

This is a pictures of the 3 Generations of the boxes.
I have the early Gen 1 gear box with the straight arm in my car (no adjustment possible any further) - right gear box in the picture

Gen2, also with a limited adjustment in the middle (curved arm)

Gen 3 with larger adjustment and the curved arm on the left side. I bough this box.

Any advise how to prep the Gen3 box before install?


Martin

Attached Thumbnails

 

w:

1) All steering boxes are tighter on-center than off-center.
2) You might send an email or PM to "Martureo" (sp.?) on this forum, steering boxes are his specialty.

Check out online post by David Petryk. Lots if good pics and info.

Be sure to turn the adjusting allen head anticlockwise to tighten. I have had good luck adjusting boxes with more than 300K on them.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Yes, I adjusted my current gear box CCW! 3 times with not noticeable improvement. It is leaking oil in addition and is the Gen1 gear box which has a limited adjustment capability.

Martin

Thanks Frank,

I did pm martureo...see if he is responding.

Martin

Hi Daantjie,

thanks for the note. I'll probably reseal the 'new' gear box. It doesn't seem to be overly complicated
I ordered the Febi Kit which should be the same as the MB kit 126 460 00 61.
Best, Martin

His rebuilds are solid.

__________________
1979 Black on Black, 300CD (sold), 1990 Black 300SE, Silver 1989 Volvo 780, 1988 300CE (vanished by the hands of a girlfriend), 1992 300CE (Rescue).

Update Nov 2022

Thanks for all your help.

Meanwhile bought a spare late W126 gear box which seemingly has the larger play self adjustment. I also gathered all information I could from the WIS (especially good is section 46-220) in order to study and renovate this box with the reseal kit plus I also ordered new steel balls.

The spare steering box is completely apart and I was studying the interiors in order to understand the mechanics and hydraulics of the box.

I have understood all the basic mechanics of the box and the hydraulics.
However I could not find out exactly what is causing the torque 'bump' at the center position in a new gear box nor could I say I did find the play reduction mechanism. The torque bump is possibly fading in older high mileage boxes... but I could not find out A) what causes mechanically the higher torque bump and therefore I cannot say how this could be restored.
And B) I could not find the automatic play reduction mechanism for 100% certainly (play reduction at center positions).
The only hint what this mechanism might be came from a comparison from my gear box to another box which is seemingly very similar but has not the auto play reduction.
The only difference between the two is a physical bump at the steering piston. This is a line where the play reduction mechanism is sliding along and a strong spring is pushing the entire piston to rotate, thus pushing the gears of piston rack to engage tighter with the steering rack and thus reduce the play.
However I am not certain that this is what exactly happens. It would be great if someone could comment on this observation (auto play reduction mechanism) and also comments about the torque bump at center position would be very welcome.


I have changed all the seals and teflon/back up rings and this is very straight forward. It takes about an hour or faster.

I have also removed all the balls from the worm gear To my amazement I found 23 balls (7.000mm). According to the WIS there should be 24 balls.
So I don't know why there were 23 only in my box.
I ordered new balls (7mm, Grade 10 balls) from England and as soon as they arrive I'll measure them and then decide if I'll take these or not.
I heard that I could get oversize balls in Germany... like 0.001mm oversize ones, unsure if this is any advantage. I guess even if there is small wear in the worm spindle and nut 0.001mm is not relevant for 'play'.

I have started to assemble parts of the box and did the first torque test as outlined in the WIS.

Again if you have any comments please let me know.

Martin

I have also seen some boxes with 23 vs 24 balls so I think this is normal. I would just replace "as found".

Thanks Daantjie,

I am so slow. I have received the new balls and they are 7.000mm

I have installed them (24 pieces!) and discarded the old balls.

The new balls 'feel' okay.
However I have only a torque instrument that can measure downb to 20Ncm, maybe 10Ncm.
I am trying to get a torque measuring tool that can measure 5 Ncm or smaller. I have printed a fitting in order to be able using a 1/4" drive to move and measure the torque for the assembly steps and adjustments according to the manual under 46-220.

As soon I have a proper instrument for measuring these small torque values can move further.

One note: I have used up almost all seal rings. I think I have another smaller o-ring left and I don't know where this is going yet. I am mentioning that because some people said there are many seals left over from the reseal kit.... which is not the case.

Best, Martin