Front wheel camber on a 68 saloon

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TerryGreen
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Front wheel camber on a 68 saloon

Post by TerryGreen »

I took the moggy in for some new tires earlier today and had the bloke at east lane tires check my tracking for me while he was at it (it was out by 7.4mm on the o/s and 3.5mm on the n/s) he said that my camber was out too. the display on his machine said o/s +2º19 and n/s +0º29. I have been told that it needs to have less than half a degree of toe out so i assume that my n/s is ok but i have something to do with the passinger side of the car. The question is what is wrong? It is driving fine (conciderably better with the tracking set but it wasnt pulling either way before it was set) Is this one of those problems that wont do any damage and i can ignore it or is it something that needs attention. Does anybody have any idea what i can do to pull it closer in line with the other side of the car. Any ideas would be appreciated. I have just ordered a load of new bushs from the minor center to c if greasing the suspension up will get rid of a squeek so i am going to have to take the front suspension apart at the weekend anyway and will have a proper look. Anybody have any ideas what could be causing it? Any advice would be appreciated.
Thanks
Terry.
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Post by Chris Morley »

I'm no expert on incorrect tracking but I hope this helps. I suffered it a while ago when the inner edge of my O/S front tyre suddenly wore down. Most tyre centres had no idea what camber / toe-in was right until I produced the Leyland workshop manual so beware of any 'advice' you are given. Most staff at tyre centres have never worked on a Minor.

I understand camber to be when the wheel is slightly tilted outwards at the top, inwards at the bottom. According to the Haynes manual it should be 1% if the Minor has rubber top link bushes or nil if there are none.

I'm not sure why they claim it needs toe-out? The BMC manual says 2.5mm toe-in. This is where the wheels are set to point slightly inwards at the front.

Also I don't understand why the tyre centre didn't change the tracking for you. :roll: It only takes a few minutes work with a spanner. From what I've read the most likely causes for poor tracking are hitting an obstacle such as a kerb or severe general wear of the tie rods & end ball joints. These parts will need replacing if the wheels continue to lose their tracking. I suggest you keep a very close eye on your new front tyres. Look out for ridges, fins of rubber or disproportionate wear at any point (especially the inside of the tyre which may wear quickly).

If you find wear is still happening try to find an old / established tyre centre and ask them if they know how a Minor's wheel alignment should be set up. Or contact a Minor specialist for advice on replacing the tie-rods.
Last edited by Chris Morley on Sun Jun 27, 2004 6:43 pm, edited 1 time in total.
TerryGreen
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Post by TerryGreen »

The tire place did set the tracking for me, i dont remmember having hit anything recently but a few years ago it had an almighty clump to the o/s as it went up a curb at 60/70, the suspension hasnt been touched since but it has been fine until the last set of tires went onto it. I may have heard it wrong but the bloke at the minor center over the phone said something about needing less than half a degree of camber. camber to me is the angle the wheel is at top to bottom, tracking is front to back. the tracking is now spot on. I was going to leave it for 50 miles or so and see what is happening with the tires. Either way it is something i would like to sort as its not right. Still, as long as the tires last a bit longer than 3 months this time.
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Post by Chris Morley »

I got the following info by typing 'wheel camber explained' into Google (what a wonderful thing the Internet is !) :D . I've actually learnt an lot in the last hour 8) .

Camber - whether you have each wheel leaning in or out from top to bottom (positive or negative)
Tracking - whether you have each wheel pointing in or out from front to back (toe in or toe out)

So my clumsy definitions were right. :wink: The only question is about toe-in / toe-out relating to the Minor. All the manuals I've read mention toe-in, not toe-out. The figure is 3/32 inch or 2.5mm. This means the front of each tyre should be 1.25mm nearer the centre of the car than at the rear (thanks Ray :wink: ). I've no idea what this figure is in degrees. This is to counteract the tendency of the tyre to toe-out at speed. However too much toe-in causes excessive wear to the inner tyre, also increasing resistance and lowering top speed slightly. Clearly if the front wheels (with identical tyres ) suffer differing camber and toe-in / out then it is less than ideal and will increase tyre wear and potentially cause 'wandering' or pulling to one side.

It seems that toe-out helps directional stability which is why it's favoured by racing car / kart engineers....

Here's a good description I nicked from the WWW: Credit to

http://website.lineone.net/~richardn/ToeIn.html

Theory

Toe refers to the amount by which a pair of wheels on an axle vary from being parallel to each other. The amount of toe can be expressed either by the number of degrees which the wheels are out of parallel, or more commonly, as the difference between the track widths as measured at the leading and trailing edges of the tires or wheels.

Toe settings affect three major areas of performance: tire wear, straight-line stability and corner entry handling characteristics.

Toe-in, or positive toe-in, or just 'toe', is when the fronts of the wheels are closer together than the backs of the wheels. This creates a stabilizing force; when traveling forward the wheels are aimed very slightly toward each other, therefore creating a small understeering tendency on that axle, therefore tending to keep the car going in a straight line. The two downsides of this are (1) as toe-in increases, the rolling resistance of the tire increases, slowing the car down and (2) it 'mutes' the ability of the car to turn into a corner, creating a little corner-entry understeer.

Zero toe is when the wheels are exactly parallel to each other. This can cause the car to wander about instead of tracking in a straight line, but at least there will be minimum rolling resistance.

Toe-out, or negative toe-in (in GPL, shown as a -ve value for toe-in: confused?) is when the leading edges of the wheels are further apart than the trailing edges. This also creates a stabilizing force and rolling resistance, but does accentuate the ability of a car to turn into a corner, creating a little corner-entry oversteer. In theory, you might have a little toe-out on the front wheels because of the Akerman steering effect.

How does the toe change dynamically during longitudinal weight transfer? In a rear-wheel drive car (eg: a Minor :wink: ) under acceleration, the front (non-driven) wheels will tend to toe themselves out and the rear (driven) wheels will tend to toe themselves in.
Last edited by Chris Morley on Sat May 01, 2004 1:27 am, edited 2 times in total.
Cam
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Post by Cam »

My tracking is way out since I replaced the steering arm on one side.

This has caused the tyres to wear and feather at the edges, as was correctly stated.

My wheels toe out now, so there is a bit of high speed 'floating' of the front wheels, as well as a lot of oversteer when turning.

The tracking is quite important, but if it is incorrectly set up then it will just cause tyre wear, and driving at normal speeds in a Minor should not cause any problems if you are aware of the car's characteristics.

Camber you will not be able to detect, especially a degree or so.

Negative camber means that the car is more stable when going into a corner hard. If you don't do this on a regular basis then a neutral set up is recommended.

Positive camber should be avoided on Minors as it does not help at all, and will simply cause uneven tyre wear and loss of traction (especially round bends!!).
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Post by Kevin »

Hi Terry
East Lane Tyres is that the one at Wembley, they have been around a long time I last used them in the 70`s and if so your local specialists are Minor Mania at Mill hill, they usually have the bushes you need in stock (they do all 3 types)
Both you and Cam prove the case for when fitting new tyres and steering parts that you should always have the tracking checked, you concern over the camber may be explained that the rubber bushes are quite old and may be the reason for the difference from side to side I would have thought that replacing them with the poly bush type rather than the original rubber type would have improved things for a longer period as they last much longer.
Cheers

Kevin
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rayofleamington
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Post by rayofleamington »

~TOE IN / TOE OUT.
Shouldn't be a big mystery but the tyre centre 'technicians' aren't usually rocket scientists...
Tracking is set with an error when stationary. The idea is to make things more stable when in motion, and to make tyres wear evenly.

Front Wheel drive:
These get set to 'toe out', as when the power is on the wheels push forward which tends to twist things a bit and cancels the toe out. Due to all of this and torque steer is usually the reason a FWD will feel awful if the front tyres do not match in terms of grip and wear.

Rear wheel drive:
These get set to slightly 'toe in', as the rolling resistance of the tyre acts to push the wheel backwards which cancels the toe in.

The tracking setting varies for each type of car based on suspension/steering stiffness, ackermann angle compensation etc......
For the Minor it is officially 3/32" (2.4mm) according to the BMC driver handbook. That means the distance between the front edges of the wheels should be 2.4mm less than the distance between the rear of the wheels.
The official settings are based on good suspension rubbers and crossply tyres! With radials and worn rubbers or on the opposite case hard poly bushes it'll not be exact, but probably close enough.
This means the front of the tyre should be 2.5mm nearer the centre of the car than the rear.
Unfortunately not as that would give double! it is between both the wheels, not each wheel to the centreline of the car.

If in doubt:
Excess wear on the inside edge = too much toe out
Excess wear on the outside edge = too much toe in.

Other settings for 'high performance'
Basically ignore tyre wear if you want to go for high performance. Excess Toe-out is often preffered as the weight transfers to the outer wheel and the lesser effect of the inner wheel adds to the cornering direction. It also helps stability when changing left/right/left as it gives a blend point between each wheel having the main bias.
If it was to much toe in, the inner wheel would act against the outer and reduce the cornering grip. On left/right/left the car would be very twitchy as it would be a rapid transition between each front wheel having the bias.

CAMBER:
For non aggressive driving, close to zero is OK.
The Minor is set to 1° positive (so my book says) when it has a rubber jointed top trunnion.
Basically under heavy load (cornering) the rubbers give a bit, and the positive camber cancels out to zero.

for 'high performance':
You want the outer tyre to sit flat on the road under cornering. As the body will roll during cornering to get the outer wheel to sit flat to the road the wheels should be set to negative camber.
The downside is you get bad tyre wear especially on wide wheels like my 265's on the Porker.


Terry:
he said that my camber was out too
Either
1. your suspension rubbers are badly worn (possible)
2. there is accident damage (possible)
3. there is badly repaired or unrepaired corrosion damage on the chassis leg (possible)
4. someone has fitted non standard eye bolts - or one is not fully done up!! (unlikely)
4) 'he' had no idea what the setting should be (common)
5) 'he' wanted to get some work (common) - I've had quotes to adjust the camber on vehicles that have no means to adjust camber! I bit my lip and said no thanks can't afford it just now ;-)
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where to break down next?
2013... managed to seize my 1275 just by driving it round the block :(
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Post by Cam »

4. someone has fitted non standard eye bolts - or one is not fully done up!! (unlikely)
A mod to get neg camber is to fit a washer between the eyebolt and chassis leg (same as the one behind the chassis leg). Not sure exactly how much this gives, but it's worth checking to see if someone has already done this!
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Post by Chris Morley »

It looks like Ray has more knowledge about this subject than the rest of us - my statement about 2.5mm front/rear of a tyre was an attempt at interpretation of several website explainations. Live and learn :roll: !

Right, so if we assume that the Haynes manual settings (set by BMC engineers who are most likely to know best) are correct, those of us with bog standard Minors want to be able to walk into a tyre centre and tell them what we want. Clearly camber is set at 1% because of the tendency of the wheels to splay out at speed. But saying 2.4 / 2.5mm toe-in to them brings a blank look. What is the figure in degrees?

Another factor to consider - the BMC settings were made assuming cross-ply tyres. Are radials more likely to toe-in or out and resist or accentuate changes in camber when cornering? And what about tyre inflation ( I run mine at 28 psi all round )?Does this have an effect?

Interesting comments about toe-out from Cam. When my inner tyre was wearing down, my Minor did display a high speed 'floating' sensation. This is slighly less noticeable now. I've always assumed that this characteristic was mainly due to the air being pushed under the front of the car. You can hardly describe the minor's underfloor as streamlined after all.. :-?
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Post by rayofleamington »

Not sure how they calculate angle - probably wheel to wheel.

Roughly it gives 0.2° between the wheel and the vehicle centreline.
= 0.4° wheel to wheel
A mod to get neg camber is to fit a washer between the eyebolt and chassis leg (same as the one behind the chassis leg). Not sure exactly how much this gives, but it's worth checking to see if someone has already done this!
Also available are neg-camber eyebolts in a range of angles, but they may be harder to spot than a washer :-s

I thought you would have some Cam!! Did you do the washer trick instead?
Ray. MMOC#47368. Forum moderator.

Jan 06: The Minor SII Africa adventure: http://www.minor-detour.com
Oct 06: back from Dresden with my Trabant 601 Kombi
Jan 07: back from a month thru North Africa (via Timbuktu) in a S3 Landy
June 07 - back from Zwickau Trabi Treffen
Aug 07 & Aug 08 - back from the Lands End to Orkney in 71 pickup
Sept 2010 - finally gave up breaking down in a SII Landy...
where to break down next?
2013... managed to seize my 1275 just by driving it round the block :(
rayofleamington
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Post by rayofleamington »

Hi Chris
high speed 'floating' sensation
Sounds like a tracking fault! It is usually more evident in the wet, especially if the front tyres are different makes or if one is more worn than the other.
What happens is the front wheels point in different directions, then rather than each wheel scrubbing evenly, one wheel grips and the other scrubs.
With that the car steers to the side, and you steer back the other way, only for the other wheel to start gripping when the weight tranfers around with slight cornering motion.

What you feel is a car that wants to wander at high speed and as mentioned it is most noticeable in the wet.
There are many other reasons for wandering but tracking is the most common.
Ray. MMOC#47368. Forum moderator.

Jan 06: The Minor SII Africa adventure: http://www.minor-detour.com
Oct 06: back from Dresden with my Trabant 601 Kombi
Jan 07: back from a month thru North Africa (via Timbuktu) in a S3 Landy
June 07 - back from Zwickau Trabi Treffen
Aug 07 & Aug 08 - back from the Lands End to Orkney in 71 pickup
Sept 2010 - finally gave up breaking down in a SII Landy...
where to break down next?
2013... managed to seize my 1275 just by driving it round the block :(
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Post by Chris Morley »

Hello Ray,

Cheers for the toe-in . 4% figure.

Yes, it was a tracking fault that quickly ruined a relatively new tyre on the O/S...by the time I noticed the wear it was close to illegal. The N/S tyre showed very slight wear on the inner edge but was O.K to continue with. I was asked if I had hit something due to the incorrect tracking.

I've done nearly 5000 miles since, so I'll soon need to check the front wheel balance. Now I can ask for the camber / toe-in settings to be checked and know what I am asking for.

Cheers, :)

Chris
olonas

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Post by olonas »

According to my BMC workshop manual when top link screwed swivel pin links and pivot pins are replaced by rubber bush top links a "U" washer, part no. 183471-Z, has to be fitted between the eyebolt and chassis leg, to maintain the correct steering geometry, in addition to the existing washer (127889-Z).
I read into this that if said washer is missing, and you have rubber (or poly?) bushes, the geometry will be incorrect.
Or were later eyebolts dimensioned to compensate for this? That could cause all sorts of confusion though!
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Post by Cam »

Ray,
I thought you would have some Cam!! Did you do the washer trick instead?
Nope, my fronts are standard at the mo, I may change to a slight neg camber when I fit my new Ford PCD hubs.
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Post by rob_dewing »

I reckon a washer 1/8" thick under the eye bolt is worth about a degree. The positioning of the eye bolt can move if the chassis leg is replaced. Also they will bend - mine moved about a 3/16 in a severe sideways incident I had a few weeks ago. Needed a new wheel too.
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Post by Chris Morley »

I've transferred this thread to the 'Tips' section as it's the board's best thread which clarifies the Morris Minor's correct wheel alignment and tracking.
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Re: Front wheel camber on a 68 saloon

Post by metalmagpie »

Michelin used to quote 0 to 1/8" toe-in in X's, if i remember correctly. As to camber, I have found that an excessive positive camber, ie with the wheels closer together at the bottom, gives very little steering ability with radials on a wet-road. A small negative camber is far better. Remember Heralds, if the rear suspension jacked up on a bend the resulting positive camber reduced the rear wheel road holding to virtually nothing and the car would reverse smartly into the nearest ditch!
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Re: Front wheel camber on a 68 saloon

Post by bpr81a »

metalmagpie wrote:Remember Heralds, if the rear suspension jacked up on a bend the resulting positive camber reduced the rear wheel road holding to virtually nothing and the car would reverse smartly into the nearest ditch!
And Spitfires :oops:

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Re: Front wheel camber on a 68 saloon

Post by bmcecosse »

And Porsches ........... and Hillman Imps!!!
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