Wheel Alignment.

[EFLImpudence]

Am I correct (I think I am) in thinking that, with rack and pinion steering, the track-rod threads should be equal on both sides?

If the answer is yes - then when they are equal but the steering wheel is off centre that means that the steering wheel itself should be altered.

Put another way, centring the steering wheel and adjusting the alignment, resulting in unequal thread lengths, would not be correct.

 

[Stivino]

Yes, it is normal for both the track rod ends to be equal.
Yes, it would indicate that the steering wheel is off centre.
Take off both ends, count the turns, and up the turns and divide by two. Put the ends back on with the new number of turns and centre steering wheel.

 

[EFLImpudence]

Thank you.

 

[Mottie]

Or…as long as the alignment is correct, tighten one side and loosen the other by the same amount until the steering wheel is centred. Obviously look closer if you have 3 threads showing on one side and 20 on the other! Most times it is not easy to just move the steering wheel. You may need a puller to remove the wheel, airbags can be a problem and even then, the steering shaft might only have 5 or 6 sides to it and moving it one way or another will make it 'out' in the other direction unless it has fine splines. I’m assuming that you have checked all steering joints and wheel bearings before checking the alignment?

If I get a car come in with an off-centre steering wheel, after I have carried out the pre-checks I straighten the wheel out by moving the track across and then I adjust the alignment equally on both sides.

 

[carmanmemoranda]

Yes, it is normal for both the track rod ends to be equal.
Yes, it would indicate that the steering wheel is off centre.
Take off both ends, count the turns, and up the turns and divide by two. Put the ends back on with the new number of turns and centre steering wheel.

Agree with this, for the correct aligning.

But then just recheck the tracking and fine tune it as needed after.

 

[EFLImpudence]

Or…as long as the alignment is correct, tighten one side and loosen the other by the same amount until the steering wheel is centred.

As long as that does not make things worse.

Obviously look closer if you have 3 threads showing on one side and 20 on the other!

Yes, that shows that the tracking has not been done correctly.

Most times it is not easy to just move the steering wheel.

Nevertheless, it might be the only way to ensure everything is straight and as it should be.

You may need a puller to remove the wheel, airbags can be a problem and even then, the steering shaft might only have 5 or 6 sides to it and moving it one way or another will make it 'out' in the other direction unless it has fine splines.

After all the manufacturer will have designed it to be straight in the first place so one of the five or six flats (or splines) will be the true position.
There are also the splines on the shaft universal joints which might have been altered.

I’m assuming that you have checked all steering joints and wheel bearings before checking the alignment?

Not yet, I have only just bought it but it had just passed its annual inspection.

If I get a car come in with an off-centre steering wheel, after I have carried out the pre-checks I straighten the wheel out by moving the track across and then I adjust the alignment equally on both sides.

I think that is what I am worried about being done.

After all, it is the wheel positions being correct and equal on both sides which is the important part.
The position of the steering wheel does not really matter or affect anything.
The steering wheel is about 15° to the left.


I had a quick look at the track rod threads and they are not equal but I think correcting that would make the steering wheel worse.

However, I am getting mixed up in my mind about which was what and where so I will have a good look tomorrow and make sure.

 

[Mottie]

The position of the steering wheel does not really matter or affect anything.

Sometimes it can prevent the indicators from self-cancelling on lane changes.

If the steering wheel is not straight, it’s normally caused by the rack not being fitted correctly in relation to the splines or it’s had a bang somewhere and something is bent. The steering wheel just doesn’t go out to that degree on its own so check everything before adjusting anything.

 

[carmanmemoranda]

Most common cause of steering wheel not centred is a change of rod end and not replaced to same position.
Then wheel not centred before tracking altered

 

[EFLImpudence]

Firstly, everything seems in good order.

I made a mistake. Not sure why but I suppose it was looking from different angles before but - the track rod threads are more or less equal; possibly one thread more one side than the other.

Next, I did not appreciate the turning ratio of steering wheel to road wheels.
The steering wheel turns around 1200° from lock to lock - from the actual straight-ahead position a bit more to the right than to the left.
Does that mean the wheels are not quite right?

Not sure about the wheels but read that 30° each way is usual, so could be a ratio of 20:1 (1200/60).

That means if the steering wheel were out by 20° to left, the wheels could be adjusted just 1° to the left each to put it straight - whilst not having too much unwanted effect on the geometry.

So, you all were right. Thank you very much.

 

[DiyNutJob]

Take it to alignment shop. DIY alignment is not possible. Even if it's slightly possible, you have no way to trust it. You shouldn't assume the tie rods would be on the same thread count on both ends. Wear and tear of the car can produce an asymmetry.

 

[EFLImpudence]

Take it to alignment shop. DIY alignment is not possible.

Well, I am not so sure about that.

Even if it's slightly possible, you have no way to trust it.

Can we trust all professionals to do it correctly?
I do not wish to besmirch any professionals on here who might be excellent - but I have been around a long time.

You shouldn't assume the tie rods would be on the same thread count on both ends. Wear and tear of the car can produce an asymmetry.

Ah, that was my original question. A 'NO' would have sufficed but it appears people's views differ.

Might this be the same situation in different alignment establishments?


Anyway - thank you for the answer.

 

[Burnerman]

It is essential to start with the steering wheel in the dead ahead position and locked there......far from being a simple rack and pinion device as in the past it is responsible for electrical self centring (Merc I believe), corner positioning lamps and variable effort power steering.
Only then can the tracking be adjusted.
It is quite easy to track your own vehicle, believe it or not - I have done just this with a steel rod with an adjustable end.....Mickey Mouse maybe but the results were fine when professionally checked.
A couple of points maybe.....
If you turn the wheels manually with the engine off, expect all sorts of curious noises as the system self bleeds once more (may take 15 minutes or longer but no need to panic)
Adjust the tracking with the car under load if air suspension plays a part - also if the hydropneumatic systems a la Citroen are found.
John

 

[DiyNutJob]

Can we trust all professionals to do it correctly?

I would trust a laser alignment shop more than I would trust you. I was a heavy duty DIY aligner once. Just passing on some wisdom. Wearing the tires the wrong way might cost you a lot more than an alignment. I imagine tires must be worth like gold dust these days. I am still on the same tires. So my DIY alignment was pretty good. But, the steering wheel jiggle over uneven road was terrible. I still get some, but the shop did a better job than I could.

 

[EFLImpudence]

I would trust a laser alignment shop more than I would trust you.

You don't know me.

The worst alignment I ever had was with a BMW 7 Series with full laser equipment, weights to simulate passengers and full tank.
Afterwards the car was all over the place.

I was a heavy duty DIY aligner once. Just passing on some wisdom. Wearing the tires the wrong way might cost you a lot more than an alignment. I imagine tires must be worth like gold dust these days. I am still on the same tires. So my DIY alignment was pretty good. But, the steering wheel jiggle over uneven road was terrible. I still get some,

Ok - I think.

but the shop did a better job than I could.

Alright, I won't ask you to do it.

 

[EFLImpudence]

It is essential to start with the steering wheel in the dead ahead position and locked there......far from being a simple rack and pinion device as in the past it is responsible for electrical self centring (Merc I believe), corner positioning lamps and variable effort power steering.
Only then can the tracking be adjusted.

Ok, but what if it is the steering wheel that has been altered for some reason.

It is quite easy to track your own vehicle, believe it or not - I have done just this with a steel rod with an adjustable end.....Mickey Mouse maybe but the results were fine when professionally checked.

Yes, it's not rocket surgery.

A couple of points maybe.....
If you turn the wheels manually with the engine off, expect all sorts of curious noises as the system self bleeds once more (may take 15 minutes or longer but no need to panic)
Adjust the tracking with the car under load if air suspension plays a part - also if the hydropneumatic systems a la Citroen are found.
John

Thank you.