Steering Box Adjustment Screw

[528i-1981]

Can this be removed with the box still in the car? I've adjusted this before, or at least I thought I did. Right now, the retaining nut is stuck and I cannot turn the screw independently after loosening the retaining nut. Can this be backed out all the way so that I can soak the screw/nut out of the car? The RealOEM figures aren't that helpful on this point. I've got some penetrating oil on it and can hit it with a torch if removal is a bad idea.

Thanks, gents.

[Mike W.]

I don't think it's removable. Look at #9 in the diagram, I believe that's the screw and it has a flange on it at the bottom which would prevent it from coming out. I think you can remove the cover, #1 and perhaps access it that way. Or maybe just start unscrewing the nut until #9 hits the cover and then the nut might continue to unscrew. I would be reluctant to apply much heat there as I think #10 is a caged bearing with plastic in it. Be careful, you don't want to strip anything.

[528i-1981]

Thanks Mike - I noticed that flange after I posted. Using a flat screwdriver bit on a ratchet and holding the collar nut with a box-end wrench, I was able to get it to move.

Do you happen to know who can rebuild these steering boxes? Mine is way past prime. I was able to pick one up on eBay of unkown origins, so my inclination is to get this new spare rebuilt and then swap it in. I've found Jay's BMW Parts, which says they don't get into the inner workings, but replace the valves and seals and reset the lash. Is that sufficient with these ZF units, or should I find someone to go in deeper? Evidently there are more than a few ball bearings that are a major pain to deal with.

[PatinaBeforePolish]

Eric,

Try Jay's BMW parts. https://www.jaysbmwparts.com/

Never used him but I understand he does nice work.

[Mike W.]

Mine is way past prime. I was able to pick one up on eBay of unkown origins, so my inclination is to get this new spare rebuilt and then swap it in. I've found Jay's BMW Parts, which says they don't get into the inner workings, but replace the valves and seals and reset the lash. Is that sufficient with these ZF units, or should I find someone to go in deeper? Evidently there are more than a few ball bearings that are a major pain to deal with.

What exactly is wrong with yours? My impression, and I haven't really been into one, is that the bearings hold up pretty well, I mean it is under pressure lube all the time, but the rack and the balls wear, the hard parts. And adjusting the screw on top can help, but only does so much.

[528i-1981]

A dead zone at center. I've monkeyed with the screw a lot, and the dead spot remains even when the box is starting to bind from overtightening. You can turn the wheel a couple degrees in either direction without reaction at the wheels. On twisty backroad, it doesn't matter a whole lot, but on the highway keeping a straight track is a challenge because fine adjustment starts late. With the front in the air, you can see that the input from the steering wheel doesn't translate immediately to the Pitman arm at center, so I'm pretty sure it's the box.

[PatinaBeforePolish]

Eric,

I know this seems obvious but have you checked the rag joint in the steering shaft?

[528i-1981]

You know, I did, but I'm going to bust out a crescent and give it another go.

[PatinaBeforePolish]

I replaced mine with a polyurethane one but can’t remember where I found it. The original looked good but must have had a bit of play as I noticed a slight difference.

[528i-1981]

I exchanged some emails with Jay Stratton who rebuilds these boxes. In essence, he said they almost never wear out internally. Seals get old and leaky and needle bearings can show signs of aging, but the internal worm and sector gears have, in his opinion, never shown signs of wear. He therefore said he could not solve the problem, and that while the tendency is to blame the box, the lack of tightness is somewhere else in the steering.

As of now, I can confirm that even the slightest movement at the wheel makes it to the flex joint, which isn't surprising. I'll work downstream to the wheels from there and check every component for play. Hopefully it's the flex joint, as that's the first target area.

Jon, Ireland Engineering has the urethane version.

-Eric

[528i-1981]

From older threads on FF it appears that the joint at the Pitman arm on the center link is frequently the culprit. The tie rods and control arms on my car are new, so this seems like a good place to focus, as well as replace the flex coupler. Most sources for the center drag link list the part as NLA, but I found a Delphi unit on Rock Auto, if anyone else is looking for one.

UPDATE: The part indexed on Rock Auto for the E12 is actually the E28 drag link, which is not interchangeable. The only source I've been able to find is a Chinese manufacturer if you buy 5 units.

UPDATE: Mesa Performance had an original BMW center link that I bought. Jim at Mesa confirmed they have at least one aftermarket center link if anyone is interested.