Anyone do their own wheel aligment?
Discussion
Back some time ago I decided to do my own wheel alignment. Bought a second hand four wheel alignment kit off ebay from a chap who obviously had no idea why he'd bought it in the first place.
Considering it came on an advertising backboard that had the transformer in I assumed it was an industrial one. Its a simple system, and after replacing the non working headlight bulbs and finding out where the adjustment screws for the bean direct and 90 degree prism are.
There seems to be a distinct lack of information on the net about how to calibrate these things, or how to use them. I spent the whole of last weekend trying to wheel align an E39 M5, and came to the conclusion that I have no idea how the garages using them ever manage to align a car, especially in the hour or so most of them seem to take.
I seem to be having difficulty finding a DECENT site on how one uses a standard four wheel alignment system and wondered if anyone has any pointers
Considering it came on an advertising backboard that had the transformer in I assumed it was an industrial one. Its a simple system, and after replacing the non working headlight bulbs and finding out where the adjustment screws for the bean direct and 90 degree prism are.
There seems to be a distinct lack of information on the net about how to calibrate these things, or how to use them. I spent the whole of last weekend trying to wheel align an E39 M5, and came to the conclusion that I have no idea how the garages using them ever manage to align a car, especially in the hour or so most of them seem to take.
I seem to be having difficulty finding a DECENT site on how one uses a standard four wheel alignment system and wondered if anyone has any pointers
wackojacko said:
Can't help you there. I learned the hard way with the manual Mirror and clamp set up.
However giving someone £60 is far more appealing than arsing around on the floor for half hour or so.
£60 quid would be a bargain for a full geometry setup these days! Last time I had it done it was well into three figures. However giving someone £60 is far more appealing than arsing around on the floor for half hour or so.
AndyLB said:
kambites said:
£60 quid would be a bargain for a full geometry setup these days! Last time I had it done it was well into three figures.
Wheel alignment on one of those hunter jobbies in Guildford with fancy before and after prints came to well less than £100 for me last yearCheapest I've ever managed to find it for the Elise is about 150 quid. This is why I'm looking into building my own rig - nearly 200 quid every year or so adds rather significantly to the overall running costs.
Edited by kambites on Friday 11th January 08:55
Don't bother. Having worked in the Engineering world all my life, with my first 6 years in a Mechanical Engineering Test department, I know firsthand how difficult it can be to get correct, repeatable measurements, even with the most sophisticated equipment. I once watched a technician in the Road Test Dept at FoMoCo Engineering centre, Dunton, set up the wheels alignment on a Cosworth Escort. It wasn't a quick process, and required some formidable measuring equipment. That's why what you see in wheel alignment centres is an expensive piece of kit. You initially need a DEAD flat reference surface to place the car on. You haven't got one. It would need the tyres with the correct pressure, probably a specified weight or payload. Then you've got to make sure the car is settled, with no stiction in the suspension pushing the wheels out of alignment. The wheels will have camber angles and toe in/out. The front wheels are also influenced by castor, plus steering geometry influence. Then, if you want to check steering, the friction of the tyre/ground will prevent accurate movement of the wheels. Forget it. Go to a good alignment centre that has the latest laser alignment kit, and have a coffee whilst they do it for you.
kambites said:
Was that checking and setting everything? If so, that's very good. I suppose to an extent it will depend on the car in question as well.
Cheapest I've ever managed to find it for the Elise is about 150 quid. This is why I'm looking into building my own rig - nearly 200 quid every year or so adds rather significantly to the overall running costs.
I've found they charge based on what they need to adjust. The last time I used a Hunter rig it was about £130, but could have been a lot more or a lot less depending on the results of the initial inspection.Cheapest I've ever managed to find it for the Elise is about 150 quid. This is why I'm looking into building my own rig - nearly 200 quid every year or so adds rather significantly to the overall running costs.
Edited by kambites on Friday 11th January 08:55
SuperVM said:
I've found they charge based on what they need to adjust. The last time I used a Hunter rig it was about £130, but could have been a lot more or a lot less depending on the results of the initial inspection.
Mine always seems to need adjustments to camber and toe at both ends and caster at the front. They slip out shockingly quickly on the Elise. Well theres my problem. I had to suck it up recently cos I thought bugger this, I'll go and have someone do it. Took the car to the local jaguar dealers for four wheel alignment. Perhaps as much to make sure my kit was calibrated than anything else. They have a laser system.
BTW not sure why people think the laser system is any more accurate than a normal ligtbulb one.
Anyhow, the car is back and still not feeling great, so I called them only to be reassured the car is as spec. Trouble is that a few simple measurements from me suggests that it isn't. I called them again, the car is a BMW btw, and I was starting to think its just me, or that I like my car better a little out of spec.
During the converstation to him, he was obviously not used to having his four wheel alignment questioned. I asked if he knew the track width on the front of the car was narrower than the track width on the rear. He replied to say this wouldn't have any effect on the alignment.
Now for the life of me I don't understand this, perhaps much as I don't seem to possibly have grasped some of the fundimentals here.
The rig I have doesn't have a name I can see on it. It has two simple flags for two wheels marked in cm from the centre of the wheel, and two light boxes which will shine a light either along their length down the side of the car, or at 90 degrees to their long axis across underneath the car. Both of these are shone onto scales marked in cm or degrees.
BTW not sure why people think the laser system is any more accurate than a normal ligtbulb one.
Anyhow, the car is back and still not feeling great, so I called them only to be reassured the car is as spec. Trouble is that a few simple measurements from me suggests that it isn't. I called them again, the car is a BMW btw, and I was starting to think its just me, or that I like my car better a little out of spec.
During the converstation to him, he was obviously not used to having his four wheel alignment questioned. I asked if he knew the track width on the front of the car was narrower than the track width on the rear. He replied to say this wouldn't have any effect on the alignment.
Now for the life of me I don't understand this, perhaps much as I don't seem to possibly have grasped some of the fundimentals here.
The rig I have doesn't have a name I can see on it. It has two simple flags for two wheels marked in cm from the centre of the wheel, and two light boxes which will shine a light either along their length down the side of the car, or at 90 degrees to their long axis across underneath the car. Both of these are shone onto scales marked in cm or degrees.
I very much doubt that a few 'simple' measurements that you've made are actually that. Just zeroing the car to a repeatable, stable reference position is virtually impossible. The very least you'd need is a dead flat surface with a flatness tolerance of <0.5mm. Then you've got to set the car to reference mass and weight distribution. Then you've got to eliminate any stiction in the suspension (hysteresis), to settle the car to a 'reference' height. Checkable by measuring from the ground to a reference position on the chassis. Getting difficult already, isn't it. Then you've got to 'zero' the steering to 'dead ahead'. I could go on, but are you getting the message ?
robinessex said:
I very much doubt that a few 'simple' measurements that you've made are actually that. Just zeroing the car to a repeatable, stable reference position is virtually impossible. The very least you'd need is a dead flat surface with a flatness tolerance of <0.5mm. Then you've got to set the car to reference mass and weight distribution. Then you've got to eliminate any stiction in the suspension (hysteresis), to settle the car to a 'reference' height. Checkable by measuring from the ground to a reference position on the chassis. Getting difficult already, isn't it. Then you've got to 'zero' the steering to 'dead ahead'. I could go on, but are you getting the message ?
Well I'm getting the message from you that its impossible.However the local garages don't have a floor with a tolerance of 0.5mm, and with all due respect aren't likely to be rocket scientists. I pretty much think all you've said there is load the car and push it forward before doing the measurements.
As much as I appreciate the input, I'm looking for practical advice from anyone who has set their car up, of which I would have thought PH would be brimming.
I'm only looking at using the same equipment that your average garage uses to the standard of an average garage, and I don't beleive for one minute they treat it as virtually impossible.
Bunch of defeatists on here this morning
.I echo that. Unless the car is zero'd each time consistently and accurately, then any subsequent measurements will be inaccurate and non repeatable. I believe modern laser alignment machines do this automatically when the car is driven on. Only then can the wheel alignment measurements be relied upon. As per my first post, when FoMoCo were aligning the wheels on a Escort Cosworth, the road wheels and tyres were replace with machined aluminum discs to improve the accuracy and repeatability of the measurements.
I'm sure some garages are good and some not so, but I suppose the thread is drifting a bit. I'm not really after a garage recommendation so much as a like minded individual to share some tips with regarding home wheel alignment.
For instance I have this machine, and after a day of trying to figure it out, I ended up simply using it as a straight line I could hang on the car wheel. It was impossible to use without sitting down and getting a calculator out and doing trigonometry for half the time.
Now I don't think for one minute that the average garage does that, and I think its likely the wheel alignment device is designed cleverly to avoid the calculator having to come out. But I can't see how.
Otherwise wheel aligment machines at great cost to the garage could simply be replaced with a bit of string and a ruler, which was effectively how I ended up using mine.
Just noticed that the mods have done their usual trick of taking a thread asking for general help and sticking it someone very few people seem to look, so I guess they have effectively killed it. Never mind, I'll go back to google.
General gassing about cars is obviously to discuss colour issues.
For instance I have this machine, and after a day of trying to figure it out, I ended up simply using it as a straight line I could hang on the car wheel. It was impossible to use without sitting down and getting a calculator out and doing trigonometry for half the time.
Now I don't think for one minute that the average garage does that, and I think its likely the wheel alignment device is designed cleverly to avoid the calculator having to come out. But I can't see how.
Otherwise wheel aligment machines at great cost to the garage could simply be replaced with a bit of string and a ruler, which was effectively how I ended up using mine.
Just noticed that the mods have done their usual trick of taking a thread asking for general help and sticking it someone very few people seem to look, so I guess they have effectively killed it. Never mind, I'll go back to google.
General gassing about cars is obviously to discuss colour issues.
See
http://www.wheels-inmotion.co.uk/tech-wheelalignsy...
Sorry to be an anti, but to do wheel alignment accurate enough to be worth while really isn't a trival task, and you do need more than a bit of string, a spirit level and some chalk.
http://www.wheels-inmotion.co.uk/tech-wheelalignsy...
Sorry to be an anti, but to do wheel alignment accurate enough to be worth while really isn't a trival task, and you do need more than a bit of string, a spirit level and some chalk.
Edited by robinessex on Friday 11th January 10:50
Edited by robinessex on Friday 11th January 10:52
People have been setting cars up successfully with bits of string and rulers for decades, so to imply you need aluminium discs and a degree in pythagoras seems pretty silly.
I use a modified 2 wheel laser align system to do 4 wheel aligning. I bought 2 laser level devices of ebay and mounted onto the ends of my 2 wheel aligner rig so they shine down the sides of the car. I made 2 wooden flags to hang off the front wheels with lines drawn vertically on them at equal intervals.
I calibrate the 2 additional laser beams by pulling a long length of string the full length of my workshop and offering the aligners up to the string and then i adjust them so the distance of the beam from the string at the far end of the workshop is the same as the distance of the beam from the string at the laser mount end.
I now have 2 beans of light parallel to each other down the side of the car. The number of divisions that these fall on the flags tells me if one rear wheel is toeing more than the other. The total toe can be read off the aligner in the normal fashion.
I hope that makes some sense, I can maybe get a pic if it helps but that wont be until next week now.
It works, is repeatable and only cost another 20 pounds on top of the 2 wheel aligner price. Ignore people who say you have to have a million pounds worth of equipment.
PS one of the least reliable/repeatable systems I ever saw was a Hunter system. The operator regularly had to hang off wheels and pull on corners of the car to get the lights "green" on the printout. And people were paying good money for that kind of bodge, but it was laser innit so it must be right Guv.
I use a modified 2 wheel laser align system to do 4 wheel aligning. I bought 2 laser level devices of ebay and mounted onto the ends of my 2 wheel aligner rig so they shine down the sides of the car. I made 2 wooden flags to hang off the front wheels with lines drawn vertically on them at equal intervals.
I calibrate the 2 additional laser beams by pulling a long length of string the full length of my workshop and offering the aligners up to the string and then i adjust them so the distance of the beam from the string at the far end of the workshop is the same as the distance of the beam from the string at the laser mount end.
I now have 2 beans of light parallel to each other down the side of the car. The number of divisions that these fall on the flags tells me if one rear wheel is toeing more than the other. The total toe can be read off the aligner in the normal fashion.
I hope that makes some sense, I can maybe get a pic if it helps but that wont be until next week now.
It works, is repeatable and only cost another 20 pounds on top of the 2 wheel aligner price. Ignore people who say you have to have a million pounds worth of equipment.
PS one of the least reliable/repeatable systems I ever saw was a Hunter system. The operator regularly had to hang off wheels and pull on corners of the car to get the lights "green" on the printout. And people were paying good money for that kind of bodge, but it was laser innit so it must be right Guv.
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