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Old 02-12-2019, 04:39 PM   #1
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Default Wheel alignment shops and issues

Based on the experiences we have had getting wheel alignments lately, and from what I have been reading on this forum and other places, it is starting to look like the whole wheel alignment business is turning into a big money making scam. Although there most certainly are some good shops out there somewhere, most us have not been able to find them consistently, it appears.


I tend to be very particular on wheel alignments, both from an accuracy and from a repeatability standpoint. The specs I like to use sometimes fall outside the "green" limits of the alignment machines, but I have found them to work better in particular vehicles. I also want tolerances on those specs to be very much tighter than the "green" limits as they are often wide enough to allow horrible handling issues.


Because I am wanting more than a normal alignment, I always go to the shop foreman or manager of whatever place I am looking at to explain plainly what I want for spec and tolerance and if it costs a bit more, I am OK with that. I tend to get the "our tech is really good and the machine extremely accurate, so we can do that easily without issue". Then, when they are done, I get the printout and it doesn't resemble what I asked for. The excuses tend to be pretty consistent between shops, including that it was taking too long, the adjusters where out of travel, it was in the green so it is OK, we test drove it and it drives great, etc. Others have gotten some excuses I don't get, like the parts are loose, when they may or may not be bad. The craziest one, that just came up on this forum, for the bad results was that they wouldn't use the adjusting cams to set the camber and caster because "it would mess up the geometry".


I think a lot of the problems are being caused by the newer 3D, 4 wheel, alignment machines, which are really nice machines if they are in perfect condition, perfectly calibrated, and run be someone who actually knows how to align a vehicle. They locate the sensors off the wheel surface, so only as good a measurement as that surface is, so no better, and maybe worse than the old systems that locate on a machined section of the wheel hub.



A huge deal in trying to use the machines comes when an adjustment is needed, especially with designs like our rear drive vans and older cars and trucks. In many cases the body needs to be lifted a bit to get at the adjusters, or maybe the wheels need to be turned a bit, and this makes using the machine basically useless for watching the screen and adjusting until the reading is correct. On the last alignment on our van, the operator jacked up the van to loosen the lock nuts, put it back down and adjusted until it read right, then jacked it back up to tighten the lock nuts. Then he had to do a complete, several minute, rescan to see the results. Surprise, surprise, it was off every time when retightened. I good tech would just jack it up, loosen, adjust the cams the amount his experience tells him to for the right change, tighten, drop and rescan. The having to do a complete rescan at every change is a huge time waster, so they don't want to do it and try to avoid changing anything. If they were using old school bubble gauges, the recheck would take well under a minute.


I think most shops have gotten into the mode of not doing any changes at all, and if it does need adjusting they use the too loose, or the adjusters are rusted tight, excuse to not do them. On most unibodies with struts, except the very early ones, they can get away with that if the vehicle has not be in an accident, I think, because they are very structurally good and don't go out of alignment very often. None of our unibodies have ever needed and caster or camber adjustment and we keep them until they are dead. Of course, one shop said my old Escort was off on camber in the middle of it's life. It still drove well and no visible camber problem or tire wear, so I took it too another place that gave the same readings it had always been, so the first machine was bad.


I think the bottom line is if you have A arm front suspension, it may be tough to get a good alignment. An old school shop or truck shop that does front wheel only aligning may be the best choice if yu can find one.



What you will hear from the normal places is that the machines are much more accurate, which I just haven't seen in my experience. Sure, the printout comes with readings to 1/100 of a degree, but I truly doubt they are accurate or repeatable to even 1/10 of a degree. For reference, if you have a bubble gauge they claim 1/8-1/4 degree accuracy, which is probably true, but can be allowed for if you check them. The bubble gauges will be very repeatable, though, which is what you need when making adjustments to prevent "hunting" with changes.


I am currently collecting what I need to do DIY alignment in the driveway at home, and trying to work out the best and most accurate procedures. There are lots of articles and videos online of how to it, but I think many of them would not give really good accuracy or repeatability, so some tweeking needed to get better results. Will I get better results than the machines? I don't know yet, and may never know because I don't think you can trust the results off of any one given machine that you compare to. If someone on a video or post says they are getting "much more accurate readings than a machine" be cautious because the almost certainly don't really know they are. I think the only real way to evaluate will long term handling consistency and tire wear, but it will take a long time to know much. Probably the most rewarding fro me will be that the cam that "is out of travel" but has 1/2 inch of space left to move, it appears, can be attempted to be moved. You never know, the hole in the frame may be too small and restricting it.
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Old 02-12-2019, 05:58 PM   #2
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Thanks booster. Looking forward to your writeup. I am due for an alignment on my 2006 210 which hasn't been checked in 40,000 miles, though tires are wearing evenly. I had 50,000 miles on last set and changed due to tire age even though I had 1/4" of tread left. I did a check of toe last time and was pretty close.

So I will use your writeup to check and adjust.
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Old 02-12-2019, 07:32 PM   #3
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I too will be watching for your reports. I think the key is the word repeatability. a couple of years ago when I was trying to get our van to drive better, I went to a local shop where I had a rapport with the main technician - he took my requests seriously and tried to give me the settings I asked for rather than settling for "the green zone".
So, I had a setting done and then drove it for a week or two and then went back to try something different.

This shop records the starting data and then the new data after changes and you get all that on a print-out when they are done. The problem I observed was that the 'starting' measurements are never the same as the previous 'ending' measurements. Because I was not satisfied with the way it drove initially, I had several (at least 5-6) re-alignments and this lack of repeatability was evident in all cases.

I think it is another case of the latest high-tech tools dumbing down the work force because people are trained to not second guess the computer since it is infallible. Problem is they forget that it is a person, not the computer, who connects the measuring devices to the vehicle and finding a tech who understands this is hard to do. Garbage in, garbage out thing.

I learned many years ago as a machinist that you cannot turn a part in a lathe, remove and subsequently re-chuck the part, and expect it be on center again without fiddling with it. Repeatability is very difficult and it requires someone who understands this and is willing to put the effort in to get it right.

Good luck,

Dave
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Old 02-12-2019, 07:51 PM   #4
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Quote:
Originally Posted by D&J Phillips View Post
I too will be watching for your reports. I think the key is the word repeatability. a couple of years ago when I was trying to get our van to drive better, I went to a local shop where I had a rapport with the main technician - he took my requests seriously and tried to give me the settings I asked for rather than settling for "the green zone".
So, I had a setting done and then drove it for a week or two and then went back to try something different.

This shop records the starting data and then the new data after changes and you get all that on a print-out when they are done. The problem I observed was that the 'starting' measurements are never the same as the previous 'ending' measurements. Because I was not satisfied with the way it drove initially, I had several (at least 5-6) re-alignments and this lack of repeatability was evident in all cases.

I think it is another case of the latest high-tech tools dumbing down the work force because people are trained to not second guess the computer since it is infallible. Problem is they forget that it is a person, not the computer, who connects the measuring devices to the vehicle and finding a tech who understands this is hard to do. Garbage in, garbage out thing.

I learned many years ago as a machinist that you cannot turn a part in a lathe, remove and subsequently re-chuck the part, and expect it be on center again without fiddling with it. Repeatability is very difficult and it requires someone who understands this and is willing to put the effort in to get it right.

Good luck,

Dave

I spent 14 years in a machine/fabrication/machinery building shop while I was in high school, college, and after graduating, so I know exactly what you are saying. I have a Bridgeport and lathe in the garage to this day.



I have done a preliminary check on the bubble gauge I got, mostly for zero point and repeatability in mounting. I leveled my small surface plate doing the .005"/1" level with turn in 180* routine to get really level and then confirm with a steel bearing ball. Put the angle plate on it, confirmed perpendicular with three different precision squares. Gauge was right on for one of the camber bubbles, 1/8* low on the other, so within their rated 1/4* degree and easy to allow for. It repeated mounting and unmounting the magnetic mount to the angle plate to and unmeasureable amount, probably less than 1/32*. I am very OK with those results. I checked the angles by shimming and calculating the mount and it tracked pretty well, very close to the 1/8* off on one and nearly right on for the other. I need to check that a bit closer, but the actual numbers aren't nearly as important as repeatability side to side on the vehicle.


We have gotten 20" of snow in the last 8 days, so it certainly will be a while before I can get out on the most level part of the driveway and see how much I have to shim the wheels to get the vehicles level there.


I don't think we can ever stress enough that accuracy is good, but repeatability makes stuff actually work right.
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Old 02-13-2019, 03:00 PM   #5
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A question for you D&J.



Do recall how big the variances were between your ending and the next starting readings? I think that would be very interesting information to help get a feel for the true repeatability of the machines.


I have asked several places to scan the vehicle twice without changing anything, but they all won't do it. It may be cost thing, but I was paying by the hour on a couple of them, so shouldn't have been. I got the feeling they didn't want anybody to see just how unrepeatable they are.
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Old 02-13-2019, 05:42 PM   #6
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Hi Booster,
I have found, copied, and grouped 4 of my alignments into one PDF file.
I have not tried to attach a PDF before so unsure if this will work.

Assuming you see the attachment, you will soon discover that these machines are not very repeatable - by comparing the "before" in a given report to the "actual" of the previous alignment, you quickly see there is not much consistency. The first one, dated 6/24, was the first at this store so the "before" and "actual" are the same.

These were all on the same vehicle, by the same technition (their senior tech), on the same machine, in the same building. No other work had been performed to the chassis between visits. At the end of this series, it was pretty obvious that they wished I would just go away...

Hope this helps,
Dave
Attached Files
File Type: pdf Xplorer allignments.pdf (1.86 MB, 13 views)
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