Steering box registration with steerign column

[djm16]

I have just had my power steering box rebuilt. Mk IIb 3 litre.

Unfortunately it needed a recon main shaft. As a result my alignment marks are now useless. This is my proposed course of action.

1) find the steering shaft mid point by seeing where it cancels the indicators evenly. Mark it.
2) find the mid point of the steering box, equal angles of rotations from each end stop (drop arm off). Mark it on the main shaft.
3) pull up steering shaft to disengage from steering box, re-engage with both marks aligned.
4) put steering wheel back on straight
5) adjust track rods and steering arms so that it tracks straight with steering wheel set at mid point.

Q1: is this a good way to go about it?
Q2: how do you loosen the steering shaft enough to pull it free of the PAS box?

[enigmas]

If your trying to find centre of the steering box and also have the pitman arm in the correct alignment it's not that difficult, although it may take a few attempts.

To find the centre of the steering box (whilst off the car proceed with the following)
Clamp a set of vice grips to the steering input shaft.
Wind the shaft clockwise (anti clockwise if that's preferable...it really doesn't matter)
When it's fully one way, wind it back fully the other way whilst carefully counting the number of turns.
Wind it back half the number of turns. Mark the shaft at TDC...that's the centre of the steering box.

On an OEM power steering box that's correctly adjusted, you should also feel the high spot at centre as it passes this point turning fractionally left or right. If you don't feel the high spot then the PS box is incorrectly adjusted.

To find virtual straight ahead for the wheels
Roughly straighten by eye.
Pick a datum point midway between the chassis rails. Use a ruler/tape measure. Mark this point with a paint pen or similar.
Measure from the steering arm tie rod ends to your datum point. (The measurement should be the same side to side)
Fit the steering box (you've marked the centre point), now fit the pitman arm.
Don't tighten the pitman arm nut too much yet.

Note:
The pitman arm is fine splined but it also has a section that has a very wide spline. So this limits your options for an incorrect fit.

Drive the car slowly up a flat level section of road and note the steering wheel position whilst drive straight ahead. It should steer straight and the steering wheel should be centred unless you've messed about with the tracking alignment. If so, you'll need to take the car for a wheel alignment.

Steering shaft coupling.
This is held in place by 2 through bolts that locate in machined grooves in the steering shafts (PS Box & column). The coupling is also splined as are the shafts. Remove the through bolts and the coupling should slide off.
That's it.

[djm16]

Lets assume for the sake of argument that nothing is correctly set on my steering set up.

The steering box has 3 and 1/4 turns lock to lock when unattached to the drop-arm. When I set the steering box exactly 1 and 5/8 turns from either lock (nominally central!) the steering box drop arm does not point directly ahead. The is no provision for repositioning the drop at intervals of less than 1/4 turn.

Secondly, the drop arm on the relay and the drop arm on the steering box are never parallel. Should they be? The WSM is no help on this at all. Google seems to suggest that they should be.

Lastly, how important is it to find the "notchy" point in the steering box to set as central? Mine does not seem to have one.

[enigmas]

Unless you've had the whole steering assembly in pieces just point the front wheels straight ahead and parallel as best you can initially. Connect it all together and check it out on the road.
The idler arm and the pitman arm set the acherman angle, so they won't be parallel. www.google.com.au/webhp?client=tablet-unknown&gws_rd=cr&ei=6KrhVeDBOoW1mwWer6DoBA#q=ackerman+steering

Notchy bit at steering box centre position.
There is a small adjustment screw with a locknut on the top of the box. Ensure that the steering box has been centralised. Loosen the locknut and turn the screw clockwise till you feel resistance (a little bit goes a long way so be gentle). Retighten the locknut. Move the steering shaft either side of centre. You should now feel a 'slight' notchiness. Adjust accordingly.

Note:
The pivot points for both the pitman arm and the steering idler arm are matched. Otherwise the car would turn differently when turning left or right. So the steering linkage from the idler arm to the steering arm (attached to the upright where the brake caliper is...once known as the kingpin) should be the same length side to side. So match the length of the steering linkage to the steering arm on the DS (This is the linkage from the pitman arm to the steering arm on the driver's side)

This should position the pitman arm correctly with the front wheels parallel. If you've messed about with the linkages take a measurement from another club members car and this should put you within the ballpark (or should I say cricket ground!)

You will need to get a wheel alignment to accurately set the toe-in though if you've altered the linkages.

[djm16]

I have the box back on again. I first set the steering wheel by centralising it to the points at which the indicators cancel (this point is re-settable, but requires removing the steering shroud). I also found the box position at which the front wheels were closest to pointing both ahead. I then re-assembled the steering isolator on the steering box shaft with the steering wheel centralised.

So why should the box be set with the notchy bit central? And why is it important?

[enigmas]

So why should the box be set with the notchy bit central? And why is it important?

Because that's the precise centre of the steering box. The 'notchy' feel is due to the 'peg' in the box passing over the high spot on the 'worm'. It's the position in the box where you drive most of the time...i.e., straight ahead.

If you have it 'off centre' not only is the turning circle affected to one side (more on one side and less on the other) but you may also be placing a load on the spool that affects power assistance as it is biased to one side. The central position is the 'at rest' point for power assistance. (Consult your WSM for a more comprehensive account)

[johnwp5bcoupe]

Good description Vince also you have to set the pre-load at some point!

[enigmas]

Aug 31, 2015 9:57:06 GMT johnwp5bcoupe said:

Good description Vince also you have to set the pre-load at some point!

Thanks John, but it only helps if its understood by the person doing the work! It can be confusing, but as you well know, if you don't understand how something works it makes it much harder to fix!