1966 steering slop

[codm80FB]

My 66 f/back has always had some slop in the steering but never quite sure if this is normal or not . There is no obvious wear in linkages and steering box look new.

I have tightened the adjuster on the box as much as I dare but today after further investigation the steering wheel/wheel alignment is approx 1/4 turn away from the centre point of the 4 1/2 tunns (lock to lock).I am now wondering whether this could be the root cause since meshing of the sector gear in the steering box is tightest around the mid point from what I understand.

Is this a correct assumption and I should adjust the wheel posiiton/ wheel linkages to the lock to lock mid point, or is it likely to be a red herring with minimal benefit.

[codm80FB]

Just to add to my earlier post, when I move the push pull the pitman arm to check the amount of play I find that the tightest area through the full steering range is around 90 -120 degrees offset to the mid stroke of the steering box which I was supprised,

My feeling is I should align the wheels to the mid point where there is the least play and live with a difference of half a turn in lock to lock range area of the the steering box,

As mentioned before judging by the exterior appearance of the steering box (and other restored parts), it looks new so do not believe wear is an issue.

Any advice welcome.

[cobraboy]

The true centre of the travel of the box is where the box gets tighter to enable straight line stability, this as you say is mid way. I remember trueing my road wheels to straight ahead whilst clamping the steering wheel set exactly 1/2 way from stop to stop.

When you have done that and re set the toe in you can work through this guide.

http://www.stangerssite.com/adjustment.html

If you have been tightening the top adjuster without carrying out the proper procedure it is possible internal damage has occurred thus making the box go tight due to this damage, in an area that is off the centre.

[codm80FB]

Point taken, i have already read the stangerssite guide. Insitu measurement of the worm is ok and seems to be within limits , I recognise is not ideal to measure in the vehicle but it would be quite a big job to remove the whole assy just to check.

I know theorectically mid point should be tightest point but by check the play at the pitman there seems to be around 1/4 turn mismatch and although I cannot ignore it could be due to damage I have been careful only to do small adjsutements (max 1/8 turn) of the adjuster..

Anyway current max torque is within limits (The effect of sector gear engagement at tightest should be 5kgf cm ontop of the 4.5-5.7kgfcm of the worm).

I know when I got the car the slop was terrible and alignment was out , I have made small improvements over the last couple of years but I am coming to conclusion that the steering box was never centered on inital setup. So straight line was not in the centre where sectore gear in the box is at tightest.
Anyway will try it and see if this gives step change., if it does then when I have enough time I may consider full removal of the box to measure and set.

[cobraboy]

If you are familiar with the correct procedure then you can still carry that out in the car with success. If you have a long column then remove the centering cone behind the steering wheel and shim / position the box on the frame rail to get the column to 'float' in the centre of the outer column tube.
Then do your torque checks in order with the Pitman arm disconnected. Good luck with it.

[codm80FB]

After measuring the preloadtorque on the shaft (worm) , it is measuring around 3kgcm (spec is 4.4 -5.7kgcm).

With sector gear engaged to give correct pre load and Front wheels off the ground , if I turn the wheels lock to lock, I can feel play when the box has moved off the tightest point at the centre of the box (there is no play in the centre approx +/- 60 degrees either side).
What I am not sure is how much is acceptable.

I would assume that this area where play is can be reduced by increasing the preload on the shaft bearings. I have tried to slacking the large lock nut using a hammer and drift (long bar), but it doesn't want to move and I don't want to go in too hard in case of damaging something. I don't have a hook wrench large enough, but even if I did, I am not sure there is sufficient space to use it.

Is there a technique I am missing to loosen this while the steering box in the car ? I really do not fancy removing the complete steering box from the car (at least not yet).
Any advice welcome from someone who has done it already.

[ALLAN R]

Essentially this steering box is quite simple. The first adjustment to do is the input shaft bearing pre-load. This to me should be done with the pittman arm detached from the steering and the adjuster nut for the sector shaft backed right off. to lift the sector shaft out of the tight meshing with the input shaft. If you go to disassemble the box you will find that the adjuster nut on top of the box is threaded into the cover of the box so to remove the cover one should first undo and remove the adjuster nut locknut then undo and remove the cover retaining nuts. To remove the cover screw the adjuster nut through the cover. The adjuster nut fits in a slot on top of the sector shaft, so by screwing it either way it can both lift or push down the sector shaft. It has some shims which controls its play in the slot of the sector shaft. With this adjustment backed off it is possible to tighten or loosen the end nut on the input shaft to get the correct input shaft preload which ensures the correct end play on the input shaft, which is essentially zero. The way the sector shaft is manufactured gives two things. The gear teeth are tapered so the further the sector shaft is pushed down the tighter the mesh with the input shaft. Also the centre teeth of the sector shaft are ground so they mesh tighter with the input shaft than the teeth on the extremity of the sector shaft. This gives the tight centre portion of the box to provide more positive steering at zero steering lock.
It sounds as if the input shaft nut of your steering box is jammed on rather tight. Some have a lock washer or tab washer. Make sure you have released any tabs. If your car is manual steering it may well have a worn box by now and I don't think there is much that one can do to rectify this other than a rebuilt box.

[codm80FB]

It is actually the adjuster nut locking ring that needs to be first slackened off which I am have an issue, once loose I should be able to adjust the nut to change the preload on the input shaft bearing (currently seems too low).
Ideally I know I should use a hook wrench (which I don't have) but there seems limited space to slacken this off with such a wrench without removing the box from the vehicle. I have tried a drift and hammer approach to no available.

[ALLAN R]

You could try a little heat, but not to much. It might just expand the nut a little to break it free.

[codm80FB]

Maybe it helps but not sure if I can get enough heat on due to the heat sink of the box. I think I will also try to get a hook wrench on it, maybe I am lucky and I have enough space!.I think part of the problem is the box (which I assume has been refurbished) was repainted when car was restored, and the paint itself probably is acting a a thread lock as well.
I may end up leaving it as it is for the moment.
I have improved the centering of wheels to be in line with the tightest point of the box as well as setting the sector gear engagement pre-load closer to where is should be, so this certainly help. The car is certainly driveable but it is now more of a wish to improve where improvements are still possible.

[ALLAN R]

A lot of the time wondering around on the road is due to alignment issues. If these suspensions are set up well they are not too bad. I have found one problem area to be the idler arm bush. This bush can feel ok but if you turn the steering when the car is stationary you might find that the arm moves up and down a lot rather than just turning right to left. This means that the front wheels are not steering precisely in the same direction. I have had to change the arm on mine twice since I've had the car.

[codm80FB]

good pointer, all lower front end looks fairly new but worth checking.

I think my biggest problem is I have no reference as to what it should be. Modern cars are so much better and bare no resemblance to 60's technology of the time.

I still believe that steering box was never correctly set up, maybe you might recall that my car used to pull to the left, turned out that the rear axles was not locating on the leaf spring spigots due to lowering blocks no reaching the recess on the axle, this resulted in the wheel base left to right had 10mm difference!!

[ALLAN R]

That's a nice bit of rear wheel steering then.

Yes modern cars with rack and pinion steering feel very different. There is much more of a "dead" bit in the centre of the classic Mustang steering. You just need to be moving the steering wheel across this dead area to keep the car straight. For a period of several months my classic was my only car. When I got another modern car I kept over steering and it felt way too pointy. It doesn't sound as if there is too much wrong but over the years the geometry of the suspension and steering changes or gets changed through maintenance. There are packer pieces behind the bolts that hold the upper control arms to the shock tower. These packers adjust both camber and caster angle and both adjustments are sensitive to a few degrees. Originally the cars were set up with almost zero camber and just a degree or two of caster, ok for the cross ply (biased ply) tyres of the day. Now with wider radial tyres I think you need about one degree of negative camber and around four degrees of positive caster. That is why I suggested an alignment shop. Its not an easy job to do because the upper control arm has the spring pressure against it so changing the packers is a PITA.

[codm80FB]

I did the caster /camber /toe in adjustment 18 months ago when I sorted out the rear axle issue takes some time fitting the shims then measuring--a nice winter job. Any am now pretty happy with that setup (measured to be camber -1.25 / caster + 4 deg/ toe in 3mm).
Unfortunately I have no history on the car and although the restoration job prob done several years ago looks good , there is a few minor topics that suggest it is not perfect and "tuning" is required.
BTW for the horn contact on the steering wheel hub(grant) what type of grease is used (mine was dry and contact surface is badly worn as a result (replacement on order). I was thinking to use a lithium multi purpose type (non conductive).

[ALLAN R]

It sounds like the geometry has been set ok. If you suspect something with the cars "straightness" you could do some measuring but I've been told that these cars were never as accurately made as modern jigged up cars, so you may find some minor alignment errors anyway. I fitted an export brace and Monte Carlo bar to my car. I found I had to jack the strut tops apart by about 1/4 in and also hang the front on axle stands to get the brace bolt holes to align. The car had sagged quite a bit over its 50 years. Since doing this the car has felt stiffer. This said I don't think the bodies on these cars are very rigid anyway.