Alignment Question
 

Hey everyone,

So I got an alignment done last weekend and everything was fine for most of the week. Then towards the end of the week it started to pull to the right and generally piss me off. The front end on the 300D was rebuilt by the previous owner back in 2010 and drove pretty well.

I was going to go back up to the alignment shop Saturday but I accidentally slept in and missed the closing time.

Here is my alignment sheet from the shop, any thoughts on it?

I dont quite know much about alignments or which degree value corresponds to what aspect. They are the only shop that is open on the weekend and one of three in the area that do Mercedes.

Why are the values on the left not equal to values on the right? Especially in the first item? I believe that is caster?? and has to do with left/right steering? Shouldn't those two numbers be equal, would not a discrepancy cause pulling to one side or another?

http://i.imgur.com/Suna27Il.jpg

I have to have my 190E aligned as well. It has all new suspension AND steering box....

I had to get out my ASE A4 study book for this one.

On the front, your cross caster should be giving you a slight pull to the left while your cross camber should be pushing you right. The slightly higher camber on the right is pretty normal in manufacturer specs for LHD cars, since it will keep you going straight on a road crowned to the right. On the rear, the cross caster is wanting to push the rear of the car to the left. All the numbers are within spec, but your front and rear caster are conspiring to give you a pull. Also, two degrees negative camber seems like a lot to me unless you drive like a thrill seeking speed demon (IOW like me:)). I don't know how much adjustability is in the 126 rear suspension, so your tech may have to try to balance it out at the front.

Thanks for the info!

Also the car in question is a 1991 300D 2.5.. I am not sure why they used a 126 chassis for the specifications.. When I took the 190E there previous it was aligned to "93 140 and all" specification.

Did you check your tire pressures? If everything was fine, most of the week, it may something as simple as low pressure in a tire. I've noticed that a sudden cold front tends to undo tire pressures, at times. I'm not sure why that is and some tire brands seem a little more prone to this problem.

I hadnt thought about tire pressures but I can check.

I was on the turnpike today and found that in the center lane, the car pulled to the left and I had to compensate to the right.

When I was in the right lane, I found the opposite. It pulled to the right and I had to compensate left.

It was not HORRIBLE but it was noticeable enough to me that it was annoying.

It absolutely infuriates me to the point of just throwing parts at the car..which is what I did with the 190E. It still needs an alignment but the steering is SOLID and has SIGNIFICANTLY improved over its previous state.

Sure it's not a worn center link or idler arm bushing? Iknow, the suspension shop is supposed to check for stuff like this, but did they inspect all links closely for wear?

Worn parts or slop in the steering box are my first thoughts.

Did they use the spreader bar to do the alignment? If not, I suppose the loading may not be realistic.

I am not sure about this. I would imagine they checked these but cannot be sure. I had the 190E's idler arm bushing replaced. I am not sure the 300D has been. I know the lower control arm bushings and ball joints were done.

Here are my records actually:
https://docs.google.com/file/d/0By8MqLgsKlwXdG5HZUlCbEkwc1k/edit

Thats what my thoughts were too. Especially since I just went through a similar ordeal with my 190E. I replaced everything except the center steering link.

The previous owner replaced the shocks, lower control arm bushings and ball joints.

The tie-rods, center link, idler arm and steering box are, presumable original or replaced prior to the previous owner as I did not see records on those.

I don't think they used a spreader bar. In the past I inquired about that they seemed to have no idea on that topic. :(

My understanding is that an alignment cannot be done PERFECTLY right without the MB spreader bar....which no one but MB seems to have.

I got a lifetime alignment at Firestone....they can get it very close (I found that the have to pull the specs from the VIN, NOT the model number), and there's one of their techs in particular who has a good deal of experience with alignments. One of the things I like about the lifetime alignment is that, if the alignment changes, you simply get it redone at no cost.

It looks like you got a pretty solid alignment for a 126;) Maybe even a 124 too!

The first value you mention as not being even is fine. It's caster, and a good tech knows to put a little less caster on the left. Generally drivers spend more time to the right of the crown of the road which causes a drift to the right. This is offset by putting less caster on the left. All cars come from the assembly plant like this. The pull moving from the left to right when you change lanes is probably because the lanes have different camber. The right lane should lean more to the right, causing more of a drift to the right.

I'd be more into having camber, the second angle being perfectly even. A difference in camber can cause a pull, but it's sort of fuzzy. A .3* delta in camber from the l to r isn't really big and the tire is a huge factor in whether or not camber will cause a pull. A 195/65/15 tire can deal with a camber delta better than a 245/45/1X tire as far as a pull is concerned.

Not using the toe bar will skew your front toe measurement. You really have less toe in the front than is indicated. The toe bar isn't a must, but I suggest compensating. The tech can add a little extra toe, or he can spread the front tires by hand with a modest amount of force, say, 20#, and see if toe is in specs while pushing. The thing about toe in on the front is that it helps with cross wind and road camber stability. If the road is tilted to the right, the weight of the car will slightly shift to the right putting more weight on the rf tire. The more toe in this tire has, the more it will resist allowing the car to drift to the right. The opposite is true for the rear axle. If there's negative toe on the rear and you're still driving on the previously mentioned road, as weight shifts to the right, the rear axle will drift to the right, preventing the car from drifting right. It's important to mind the relationship of front and rear toe if you don't like your car pulling in a different direction every time you change lanes.

Rear camber is a function of rear ride height. The '91 300d sits pretty low and will have corresponding negative camber. Negative camber does help cornering traction but not straight line traction. It's not that big of a deal but it will wear tires. Replacing the rear lower control arm bushings and the bushings in the rear knuckle where the LCA attaches might help if they're worn but the only way to adjust rear camber is to buy the Kmac bushings which cost 360-400 shipped.

Throwing parts? Throw them all at it. In a perfect world with unlimited funds, replace every piece of rubber on the front and rear ends. If your idler arm bushings aren't pretty new, I bet there's some play. As a front end guy, I have zero tolerance for idler arm slop. I like fresh LCA bushings and ball joints too. I'd replace them every 100k regardless of condition on a W124. Steering gear slop, while annoying, does not affect your alignment.

Thanks for the info Ray! I wish you were closer so you could drive the car and see how it feels. Maybe I'm just overly sensitive to these things!

I dont think the idler arm bushings are new or even relatively new. Probably never been replaced. So maybe I'll have those done. Its fairly cheap. The front LCA rubber and ball joints are only a few years old so and they have less than 30k on them I would say.

With regard to the rear camber, there are cheaper solutions than the Kmac arms. I have some arms installed on my 190E that were <100 total.

Perhaps after this weather clears up and I can get the 190E aligned and back on the road, I'll send the 300D down for an idler bushing and general checkup.

The only best way of alignment is to note down the alignment specs from the build code - e.g my car is a W124.131 - which calls for a different alignment than the older 2.5 turbo - WHY??? I have no idea - maybe because the E300D sits lower at the front and uses ET44 wheels.

The spreader bar is mandatory to literally force the wheels apart - otherwise you end up with a squirrelly feel and the car will want to roll askew as a slight toe change in the front of a MB dictates a lot of change in camber.

Can you elaborate on the "roll askew" portion? I'm fairly certain they did not use a spreader bar...

when aligned correctly the wheels sit straight, true and centred when driving down the road, a bit off on toe on these MB and your camber also goes to whack so you then end up with a tyre trying to roll either outwards and also leaned out.

You can imagine the setup like 2 motorcycles (due to the excessive caster on our cars) if you tilt the handlebars on the bike the wheel slops to one side - this is what im calling rolling askew if you have bad toe on your car, the bike wont work but a car will as as you still have one more set of wheels back to front keeping the car somewhat straight.

I think this is the case for my 300D. Sometimes it feel OK, like on the freshly paved freeway just before the turn pike. But then on some parts of the turn pike, you can feel the road dip up and down/left to right in the steering. Just like your two motorcycles setup analogy.

I am not sure what to do about it though. If a spreader bar is required to ensure a PROPER alignment I think my only recourse is a dealership alignment. They are $125. I'm OK with paying that so long as they ACTUALLY do a good job.

I particularly don't like the shop I go to currently, but they are the only other place in town that will do a MB. Sears and the other places won't touch them.
I forget what the incident was but they were having trouble do something on my 190E and blamed it on wrong parts, which I personally installed. I do not install wrong parts....

I did a DIY toe alignment at home with thread stretched between two jack stands and for the spreader bar I had 2 pieces of 2x4 lumber and a bathroom scale on either side of the jack - you may need to support this contraption.

I set the toe to equal distance and just a smidge more for wheel to point inwards. Car is rolling pretty good. For absolute correct alignment, the dealership should have the 5 finger spider that go into the wheel holes (the small holes between the lugs) so they actually measure from the hub. They should also use the spreader bar and follow the correct setup technique in which toe is set last.

Gah driving up today was horrible.

To me, it feels like the car is overly sensitive to the road surface. I felt like I was micro-managing the steering wheel, correcting it way more often than I should.

I am going to call the dealership and see if they can do it properly? Is there any specific questions that I should ask to make sure they are not full of it? Should I ask if they use a spreader bar? etc?

Are you ready to try and do the job yourself yet?

Ahh not quite! Too cold here still. I don't mind paying, so long as the job is done right. I've always been leary of going to the dealer as they were more expensive but the more I thought about it they're only $125. I paid $98 for the last alignment. $25 difference isnt bad especially if the job is done well/correct.

I don't know if they've started this in the US but over here some Mercedes dealerships have started specialising in classic 'Benzes - apparently these particular dealerships are better suited to our needs.

Failing that you should ask to speak to the chief mechanic - the guy at "my" dealership is really knowledgeable and very helpful. Get past the high pressure sales desk and you should hopefully find some real people who will help. The extra money that you pay should be worth it.

Beware of dealers and call around first. One nearby that claims lowest labor rates in the area charges $198, while another charges $98.

There are not too many within 30 miles or so of me. The one closest (6 miles--right most dot on link below) said $125.

Mercedes-Benz dealers in zip code 44446

All the other non-dealership places in there area...two said they could do it.. One I've been going to and am not too terribly pleased. The other we used once and they were OK. They are only open weekdays which makes it impossible as I work lol.

get your cars alignment specs from ps2cho website and note them down, make sure that the model they put in is 124.128 for your car not W126 all models as your original sheet shows.

If your alignment place does not have a spreader, they can substitute for a human spreader bar (usually a tall strong chap) to push the wheels apart. The toe is then set - this should be the last job tho.

I DIY and got it quite OK. Im going to roll down to a nice toyota shop that has a nice hunter machine and ask them to check it for me.

Did you set up the caster and camber too? Did you start a thread on this? {If so I missed it sorry}

With your home made spreader bar do you feel that the force you apply is more or less the force needed to get the front wheels to spread with out pushing too hard on the tyre side walls?

the spreader bar force applied is about 65 kg - the reason to use scales in between is to give some cushion whilst adjusting the toe.

I did not setup camber or caster as I did not know of a way how to measure caster without actually measuring from the ball joint clamp itself. Im thinking of making something from wood for this purpose. - That may cause a sign to be plastered on my forehead one morning saying 'obsessive gear head' or something.

On a W123 the spreader force is 110N - 120N which is about 11 kgf

I wrote up a procedure for the caster and camber adjustments here if you are interested

http://www.peachparts.com/shopforum/diesel-discussion/284337-how-i-adjusted-toe-out-camber-caster-my-w123-300d.html

(Yet again W123 based information => 1st gen W126 is about the same though)

man, I need to check spelling before posting - I lost the decimal

nice DIY,

to measure the caster on a w124 and 201 a U shaped piece is hung on the hub carrier and ont he ball joint clamp nut according to the FSM - it takes its measurement from a scale that is printed onto it.

I had my dad call the dealership as I am at work...

Talked to Larry..in service...not too much help
they have no guarantee that comes with the alignment
because of the road conditions and all the adjustments...he
was not sure about the spreader bar..said that they would follow
what ever the Mercedes process calls for.

...hmmmm

Hi JD
How does your car drive when compared to previous, before the alignment.

Was there a reason that you took it in? Tires wearing funny, pulling?

The best alignment guy around here works with very basic tools. No electronics. Everybody swears by (not at) him. His place is in a flood plain and about every other year he puts his tools up on high shelves and closes down.

See this is what I am never sure of...

Was my car simply out of align?
Are they an incompetent shop when it comes to MB?
Did they do it right and it reveals a worn steering part or something?

Is my steering box getting sloppy?

I'd replaced both front springs as one was broken. This raised the front end of the car up by a good two inches or so. I can't remember 100% right now why I took it in but It seemed like it was pulling. I also had new tires put on just a few days prior as well.

My 190E has all new suspension and a rebuilt steering box. I am hesitant to let them align it...

The dealer has not instilled any confidence in my dad as the guy seemed a bit clueless on the spreader bar question.

The reason I asked was because I have never noticed much difference in the way the car drives when I have had them "aligned" I am excluding the couple of times that I have bent suspension members from going off the road and such.

Actually to my limited knowledge the original numbers didn't look that bad. Sure some were not to what another mercedes had but still they were both pointed down the road. All of the wheels are suspended in rubber bushings and probably flex at least a degree when running down the road.

Not saying any thing about your experience but confirms my suspension ideals "if it aint broke don't fix it. "

My guess is that once you drop another couple of bills at the dealer it will drive about the same. Hope I am wrong.

Well most of the time when I take a car in for alignment I usually can tell/feel a difference afterwards and looking at the before and after measurements of all my alignments there was clearly something amiss.

You are correct the bushings and such would flex when driving down the road, which is why Mercedes says you should perform certain points of the alignment with a spreader bar..to pre-load the bushings so that you alignment numbers take effect when the car is on the pavement.

In the 190E, there was definite slop in the gearbox. I replaced that and the steering/handing is vastly improved. However the toe needs adjusted as the gear box was installed like one or two splines out of perfectly straight. I am leary of just taking this to the place I've been going. I spent oodles of money on the suspension rebuild. I dont want to get it aligned and not be happy with the results only to have to have it REDONE by someone who can do it right.

I think what I am going to do is:

1) Have the dealership check the steering box/linkage for slop.
2) If its within spec, perform the alignment as per Mercedes spec. Use the spreader bar as called for. According to what I've seen, every Mercedes requires one to preload the suspension.

http://www.peachparts.com/shopforum/569570-post18.html

So far I've only gone to two places for alignments. One I was not happy with any of the results nor do I particularly like going to them (there was an incident involving my 190E and some parts I had just installed, and they blamed me for something and said I installed the wrong MB parts or something) and the other place I had them align the 420SEL. The alignment was satisfactory however the 420 needs a front end rebuild so there is slop everywhere..

On a side note...I read somewhere that Hunter requires people to buy the spreader bar when they buy a new machine...or something to that extent..

Hunter didn't mention the bar when we got our new machine a few months ago, but we're a Ford dealer. As I said, I don't see the spreader being deal breaker. I've aligned my Merc fleet without it and I'm satisfied that the results are as good as they're going to get, considering all the bushing mush that Merc designed into their suspensions. If you get some nice stiff poly LCA bushings, the spreader bar shouldn't be used and your front end will gain more bite in corners than you thought possible. All that caster is pretty nice when your bushings aren't moving all over the place.

FYI, it's not accepted practice to adjust toe to correct spline offset. The spines should be clocked correctly, otherwise gear mesh will be messed up and your pitman/idler arms won't be oriented correctly and your linkage geometry will be thrown off.

Hmmmm. The LCA bushings on the 300D are not particularly old. I think my records show they were replaced in late 2010. The rear end however, has not had any work done as far as I am aware.

I had just assumed it was a spline offset issue. If I did take it to an alignment shop and they discover that the spline offset is incorrect is that something that they would correct? Or would I have to take it back to my original shop then back to the alignment shop?

IMO, brand new bushings are too soft to adequately maintain alignment, hence the spreader bar. New LCA bushings are one of the first things I do to new additions to the fleet. Just coil spring force on the lower control arm is enough to cause visible bushing deflection- even on a brand new bushings. They do a fine job of insulating the chassis from vibration, a poor job of maintaining alignment angles.

Is your wheel 90* off center or just a little off? There's no guarantee that correct spine alignment will put you wheel exactly where it was before, but if your wheel is off center enough to be improved by re-clocking the splines, if even by one spline, then it's best to go that route before aligning. FYI, it's pretty simple DIY. Just take the pinch bolt off by the rag joint, pry the steering shaft into the firewall, twist and slide back in.

The 190E actually have sport bushings in the LCA's. Hopefully a bit stiffer than the normal/stock level rubber. I imagine the 300D has stock level of firmness bushings in it. It will undoubtedly need the spreader bar. I've read many threads on many MB forums that indicate the need for a spreader bar or equivalent to do the alignement right for the exact reason we're discussing here.

The wheel is maybe 5-10 degree off. Not 90. Its been a while since I've driven the 190 so I may be recalling incorrectly but I do know that it was NOT enormously off.

There's probably around 30 splines on the input shaft, 36 would make 10* per spline.

One description that I read by someone who does may MBZ alignments is that he does not use the spreader bar and has gotten good results. He surmised that the reason is that toe specs cover a wide enough range that he gets close enough without the bar. Apparently toe changes to more negative at speed hence the use of the spreader bar to mimic conditions while driving.

My take on most alignment techs is that they are incompetent and only have a rudimentary understanding. They put the car on the machine and do what the machine says. They don't know how to compensate for worn parts and work on whatever comes in and don't have specific knowledge about a given car.

I've read that MBZ has much more caster than other cars ~10* vs 3* on my truck for example. The larger caster makes steering more tuneable but causes one setting to impact the other. FSM says that changing caster causes camber tp change by approx 1/3. Changing camber causes about a 1 to 1 change in caster.

I had 1 tech give me the SD back with both front wheels tilted to the passenger side. I put it on a rack and saw enough adjustment to do it properly. Apparently the issue was 1 setting affected another and the tech was chasing his tail and gave up.

The next guy gave it back with settings that obviously cause a pull to the right. It does. I haven't had time to take it back but will. There is no adjustment available on the rear and my back tires point right.

My next step is to go back with the FSM and show them how to set things. I think adding more caster to the right will make it steer straight. Ass/u/me - ing the machine is reading correctly, I expect/hope to be done. I haven't found any good places to take the car so am working with what is available.

I intend to change bushings in the rear when the weather breaks. Hopefully that will fix the back alignment. Nothing looks bent.

I have been much happier with the way my car drives since I started doing the toe adjustment my self and setting the tires to run parallel. I am not wearing out tires so fast and the car handles a lot better than when I had it aligned at a shop.

So here is a question, since I've never actually watch/seen someone do an alignment..

Do they do the alignment with the car on a lift with the suspension hanging? Or on a drive on lift? Wheels on, right?

I was talking to a friend of mine who has a Dodge Charger, which has a decent number of Mercedes designed/influence suspension components, and he said the Charger alignment is done with the car on a drive-on lift so that the suspension is loaded down.

Why is (or maybe it is an I am unware) that the case for the 124?

Im going to have the dealership work on it tomorrow. I figure I would give them a shot. I dont have the time or desire to do it my self really..plus its 10F outside today.. 65F this past Tuesday but 10F today. LOL.

The suspension geometry is somewhat different with the weight off - there's little point in aligning the wheels of the General Lee when it is flying; {steering / suspension geometry} it is of more use when the rubber hits the dirt again.

You mean the General Lee can't be steered in the air? Poppycock!

You are correct - sorry - the General Lee is truly a magnificent beast that can do everything; very poor example from me...

any car that is aligned is set up on a level rack or pit and slip plates under the front wheels, the car is not supposed to be backed up or steered while doing this, then the foot brakes are jammed on.

The jamming of the brakes is of no use if the car is FWD as the front bearings are uber tight anyway.

Well I took it down to the dealership Saturday. Here's an update:

The service manager was very receptive and attentive. He asked questions and listened to what I had to say and seemed genuinely interested in helping out and not just throwing money at the problem. He said when he got in that morning he talked to the alignment techs about the problem and said that they suspected there might be steering slop or a worn component and that they would check it out but not do any work that was not approved or required (i.e would not align the car is something is bad etc).

I told them about my past experiences with other shops and he said that, in fact, they get a lot of alignment business because other shops simply can't or won't do the alignment or do it , but do it poorly, etc.

The wanted $129 plus fees, taxes, etc for the alignment should the techs/mechs say that thats what was needed. I OK'd that and they threw in a complimentary car wash.

They closed at 4pm that day. I hadn't heard a call and we decided to head back down around 315 or so as we'd told them that I needed the car back for Monday. The car was still up on the rack, I could see someone working on it. Another manager said that we should just hang loose, it might take some time. It wasn't until around 430 did I get the car back.

I forgot to ask for a before-after sheet, it was a half hour after close and everything was closed/off. I'll was going to call back yesterday but didn't get around to it.

So far the alignment has been a good improvement over the old. The car tracks well, with minimal need to compensate.

Hopefully this makes sense:
With the previous alignment, the road surface curvature/warp/etc would be directly translated into the steering wheel and cause me to have to compensate often. With the new alignment this curvature is translated into the suspension. I can feel the road surface with the front end but it does not effect my steering like the previous. The car does not feel like its being pushed all over the road. Steering is more predictable and such.

Well that sounds a lot safer.

Try and get the sheet if you can - it might be entertaining to see the difference between the two jobs.

Please post the final specs when you get them..