Adjusting Your Steering Box

Discussion in 'How To' started by snotty, Aug 25, 2015.

  1. Here's how to adjust your steering box - late alloy one, but I'd imagine the earlier cast ones are much the same.

    A precondition of getting slop out of your steering is that all ball joints, coupler and swivel pin are in good shape. Also that your steering box isn't piddling oil out and suchlike. To service the box - perfectly possible if someone hasn't knocked a chunk out of the worm while parking - you need to take it off. Pop front drag link balljoint off, disconnect coupler, unbolt it and pass it through the chassis with drop arm still attached. Probably best to loosen the big nut first and retighten it when it's back on the van. Removing the drop arm is the hardest part. You'll likely need a press or a hydraulic puller. Don't try pulling it off when you're under the van: you'll get a face-full of exploding puller. Index marks on the arm and shaft help you put it back on in the right position.

    When it's off, you need to find the mid position of the box. The steering box is the centre of your steering universe, not the position of the front wheels. It doesn't matter which way the steering wheel or front wheels are pointing - nobody cares. Wind it lock to lock, on or off the van, and find the exact mid point. From memory, it's about 2 3/4 turns lock to lock. When it's centred, the pointer on the top dust seal should line up with the little square on the steering box casting. If it's not, turn it round until it is. The pointer/block will enable you to feel for centred-ness when it's under the van.

    This obsession with centred-ness lets you make use of a handy feature that ZF designed in: starting at about 180º either side of straight ahead, the box stiffens up slightly to stop you wandering. This preload is built in and we might as well make use of it.

    Adjustment: jack the front of the van up, centre the box (your steering wheel may end up wonky, don't worry about it), loosen the adjuster lock nut and pop the front drag link ball joint. Get the link out of the way. Turn the steering wheel 180º to one side or the other. Lying under the van, grab the drop arm with one hand and stick a screwdriver in the slotted adjuster screw with the other. Waggle the drop arm back and forth slightly. You should hear it "click-click-click" due to free play. Turn the adjuster in slowly until the clicking suddenly stops. That's it. Free play removed with the box just out of the preload position. Tighten up the lock nut without moving the adjuster screw (actually easier said than done...).

    To be avoided: if you adjust free play with the box in the centred position, you'll just introduce even more play when it's in use. If you adjust the box when the wheels are toward full lock, the box will likely bind when you're driving around straight-ahead, and you'll head off into the nearest hedge.

    Once properly adjusted, centre the box again, take the steering wheel off and stick it back on in the straight-ahead position. That's the box and wheel done.

    You've now got to make sure that the front wheels are actually pointing straight ahead with the box centred. You do this using the adjuster on the drag link. As the link gets slightly longer or shorter, it will move the wheels accordingly. Best way to do this in my experience is to set it by eye, more or less, then go for a drive. It's hard to judge unless you're moving, and you may need to drive a bit, stop, centre the box (have a grope for your pointer under the van), pop the balljoint off and tweak the length. A right pain, but you do get there eventually. Probably best to get the tracking checked once you've set everything up.

    That's it. Worth doing, IMHO. Bay steering is nowhere near as dire as folk make out. If it's set up properly, it's just fine.
    Last edited by a moderator: Nov 28, 2015
  2. PS: your steering should have a fair amount of play in it at full lock. That's how it's designed. I don't know why.
  3. WOW!! That's a good lesson..............well done!:thumbsup:
    Every time I yank on something, and the free play goes 'click, click, click' I will think of you!;)
  4. A note if you're having trouble getting the drop arm off. If you've cranked up your puller - even a hydraulic one - and it's still not shifting, get two large hammers, creep up on it from the rear, and clap the two hammers on the sides of the drop arm boss. Give it a really good belt. The hammer blows have only got to (temporarily) distort the casting/forging by a fraction of a mm to break the taper. The arm should come flying off.
  5. Because when steering boxes were first invented/used they naturally wore more in the middle as most driving is done there. When the slop was subsequently adjusted out, turning a corner would get it to a tight bit and jam. And it doesn't matter if there's slop when you're cornering.

    I bought a new pre-adjusted prototype box and it was so stiff it could barely be turned by hand.
    snotty likes this.
  6. Seems a reasonable hypothesis!
    PeterW3035 and pkrboo like this.
  7. I like @snotty 's version better than Bentley's.
  8. Don’t encourage him..:)
    Mark Darby likes this.
  9. Much better, I think ;)
    dubsurftones and Mark Darby like this.
  10. @snotty before I fit my box to van thought I'd have a run through this as a practise and see what's what.
    Centred the box, turned shaft 180° , checked for free play by waggling drop arm and there was minimal play so thought alls good , will just need minimal adjustment once on van.
    Then I turned the shaft back to centre and 180° the other way expecting the play at that point to be similar. But there is no play, in fact I have to turn the shaft another 90° (so now gone 270° away from centre) until I start to feel play.
    Is this correct?
    Is this what the adjustment will sort, so once the adjustment is complete will the play (or lack of) at 180° away from centre be equal in both directions?
    Or is something amiss here , I was expecting the amount of play (whether too much, just right, or none) to be similar whichever way I turned from centre.
  11. No idea, mate. Does sound odd. Mine was pretty straightforward to set up.

    How many turns total lock to lock have you got?
  12. About 3.5 turns lock to lock, so thats ok
  13. I recall mine was about 2 3/4, if that means anything. Sorry, no answers mate. I'd stick it on the van and see how it goes. Just don't adjust the play out when it's on full lock, or it may bind in the centre.
  14. Had a fiddle and got it as best I can, the adjuster is now wound pretty much all the way in, still not as good as id expect it to be but have remembered that the output shaft bush was worn so that won't help.
    Will see how it feels when I finally drive it
  15. Mine is 3.5 turns lock to lock too so that sounds OK actually - mine's a '75 if that makes a difference.
    snotty likes this.
  16. Odd. If I can find it, I'll check my spare 78 box.
  17. Great thread managed to center my box tonight 3 1/2 turns from lock to lock.

    When resetting the drag link has now got me thinking I have had to take the securing nut off the ball join to get it anywhere near with the wheels being centered

    Anyone got any thoughts, as I'm utterly confused. [​IMG][​IMG]

    Is moving the actual drop arm by removing it and re positioning actually part of the process as that's the only thing I haven't done.

    Scrap that paragraph above, I took the nut off the drop arm and can confirm its installed as mentioned in the bentley manual with the notches lining up .

    Sent from my Pixel 3 XL using Tapatalk
    Last edited: Aug 5, 2020

Share This Page