will_w204

So I did the 4th alignment on my 2008 GL450 CPO in a year last month. This is 4 alignments in 18k miles. I do not hit potholes or curbs. The vehicle never really seems to pull when it's out of alignment, it just gets squirrelly and loose up front. Last December, I had the foreman ride with me, then drive it, and he claimed it drives and rides like every 2008 GL he has serviced. BS. They replaced something small and incidental IIRC, but it didn't help. I ended up taking the vehicle the next month to my indie shop, and a Hunter alignment for $65 solved the issue. But then, I've needed THREE since then! Each time, I can tell it's out because the vehicle gives you MUCH more head-toss than normal. The dealer service people can't seem to tell the difference between the tight, normal, "controlled" head-toss that these things give you when they are balanced and tight, from the bounce, bob and weave type of head-toss that I can clearly feel in the seat of the pants.

Every time it goes out it's the TOE! Why TOE? In all cases, the RIGHT toe was out, in 2 of the cases BOTH sides the toe was out.

Is there some wear part that would be related to TOE?

I don't get it, This car is so firm and well-planted when aligned, and so irritating to drive and keep on the road when the toe goes out, Not to mention, I'm trying to preserve the Toyo Versados I put on 12k miles ago, that I've rotated and balanced every 3k.

Car is under 3/135 CPO until 10/16 and has 98k on it now

alx

The versados are the spongiest luxury tire known to man. That alone is prolly your major cause for the vague steering and head toss. Also if alignment is off after a short mileage driven this is indication of worn parts or most of the time alignment tech error.

It could be also airmatic height sensor levers freezing (due to rust) and messing up the ride height. The truck will sit at different height (up to an inch) on different days

will_w204

Thanks ALX. The Versados have never felt spongy when the vehicle is properly aligned and they are inflated to 34 cold PSI all around.

Worn parts are my suspicion - but which parts? What would you hint that the shop should look for?

It was a PA car and did have rust underneath, and some parts were replaced due to this. I have had ride height issues, but they were corrected with new rear bags and a new front strut (2 separate occasions). They did a leak test in December and claimed to find nothing. I have woken up to find it sitting low, but this was explained by it being cool one spring evening and then sitting all day in the baking sun on the first 90* day we had, via blowing off excess pressure. It pumped back up after that and has appeared normmal every since.

alx

Your ride height is messed up and thus your alignment is spaghetti. As long as height moves around no alignment is possible.

Assuming no worn parts (should be checked visually) it could be one of two things:

A few nights in a row park at the same spot. Once out of the car measure ride height on all four corners. Does it fluctuate day-to-day by more than 1/3 on any of the corners? If it does your height sensor dog bones / levers are frozen and twisted or you have other airmatic issues that cause variable hight.

If truck height is pretty much constant night-to-night you have generic hight issues- I wonder if somebody has played with your calibration before and did a bad job. The result would be improper ride height and bouncy ride if too high or darty one if too low. In that case a ride calibration will help.

And your truck should never lower itself much overnight regardless of temp swings. The x164 (and x166) just don't do that unless there is a problem.

will_w204

Thanks again ALX. The previous 2 warranty repairs were performed after the photos of my measuring tape showed 2-2.5" uneven clearance on all corners between the top of the tire and the fender lip.

They said last time that, even though my measuring tape showed 2.5" clearance all around, because it was even all around it was the system blowing off pressure, not a leak. True/False?

So, you're saying the ride height calibration is something I should pay for? Why does it feel good and settled right after the alignment, but then a few hundred miles later, it feels like spaghetti again? To me, if the ride height was screwed, the alignment would not feel right from the outset. True? False?

The service manager is supposed to be calling me back to determine how to proceed for my soon-to-be scheduled latest appointment. I'm going to be really pissed if I spend $400 on ride height adjustments and alignments, only for the vehicle to go into spaghetti mode again in 500 miles, necessitating a FIFTH appointment, to determine I didn't really need to spend $400 the last time because they neglected to find the real culprit.

alx

Couple clarifying thoughts:

1. Ride hight needs to be almost the same on each axle side to side- not all around. The rear will sit a little higher (butt up) and that is OK. Don't expect ride hight To be the same on all four corners.

2. Your bouncy ride imo is due to ride height being overall too high. This might happen when your dog bones freeze due to rust. All older trucks in the north east have that problem. There are little metal ball joints on both ends of the plastic dog bones and salt and sand get inside and they freeze twisted resulting in the truck sitting higher. Very very common. They also like to squeak when it gets cold. Very common too and very annoying

3. Now Your alignment problems are due to inconsistent ride height - not too much height. Often the dog bones will not completely freeze but move/ bind between two positions resulting in two ride Heights. You get aligned in one of them then later they skip to the other position and your alignment is void

This is what needs to get done (assuming lower control arm bushings Front and back and steering arm ball joints on the front are in good health):

Dog bones need to be checked for binding and freezing. Removal, cleaning and grease do wonders. Ideally the height sensors also need to be read via star/ das and plausibility should be confirmed as you might have a bad height sensor in the the mix.

Once consistent ride height is achieved (in each corner height is always the same within 1/2" over few days) if the truck is uneven side to side height calibration should be performed. In reality if nobody has mucked up with the factory calibration at this point when dog bones move freely the truck should be back to factory ride hight so no calibration is needed.

Once you have consistent height within factory specs alignment might not even be needed, but certainly can be done if truck is pulling or uneven tire wear is observed. When on the alignment rack the truck needs to be raised and then lowered at least twice and confirmed that both times it settles at the same height at which alignment should be done. This is also the time to grab the truck by the roof rail and shake it side to side to confirm it has settled nicely. If it doesn't settle at the same height see above for r&r of dog bones and checking height sensors.

will_w204

Thanks ALX; this is some of the most detailed, illuminating and seemingly-relevant information I have found, and it just makes sense. I will take this to the dealer next week and report back.

Maybe a temporary fix is to go off-roading and unstick any stuck parts? ;=)

BlownV8

Spray some liquid wrench on the air matic "suspension bones" so they will be able to adjust.

will_w204

ALX, can you tell me what "dogbones" are? You mean control arms? Sway bar/tie rod links? Took the car to the service expert today, at first he didn't think there was an issue, but we drove another GL with 19s from the lot back to back, and I noticed an immediate difference, he seemed to say without saying so that yeah, there was a difference. Quick climb under the front and it appears the right link of the sway bar is loose. Car is tracking straight so didn't feel the need to check alignment, but the car will go back for its "formal" appointment Tuesday, whereby he will be checking underneath more thoroughly. We both were confused as to what you mean by "dogbones," and also, he says a height sensor being bad would throw a code/MIL?

alx

Dog bones are the little black plastic levers attached to the height sensor arms on one end and the suspension on the other end. They need to move freely on both ends of their little ball joints.

A bad height sensor can throw a code in the airmatic module or might not. I have seen both behaviors. In either scenario there will no indication on the dashboard of said malfunction. The code will be visible only in das.

Also ask when doing the height calibration to make sure the air pressure on each corner is about the same side to side. Otherwise the height might be good, but the frame/ suspension can be twisted/ under stress which also results in bouncy ride. For example the truck might be even but have the following pressures - FR 8.3, FL 6.8, RR 7.1, RL 9.1 (bars). In this case the right hand side is OK (those are actual values) but the left hand side is soft on the front, but at the right height because the rear left is proping the front up because it is running extra pressure. Now needless to say the truck will appear level, but the suspenson is all messed up. I have seen quite a few twisted trucks like that because the read out for the pressures is on a different screen than the one for the calibration and techs don't look there. Given the above numbers, a properly calibrated truck will run about 8.3 bars on both front corners and 7.1 bars on both rear corners. Those are example values, but actual average in reality. If pressures are good but at this point truck sits funny - you have bad mechanical parts (suspension bushings/ joints/ frozen dog bones).

Again, all this assumes mechanically your suspension is sound and all bushings and ball joints have been checked out.

jamesstock

Check bushings / tire-rod / bearings / ball joints etc... mostly suspension components / spindle .

will_w204

Well, here's what was done. After 3 days, 3 test drives, and even comparing a wholesale piece (08GL320 with 155k, which felt MUCH tighter than mine ever has), it was clear and evident that both sway bar bushings were toast. It was basically rocking around and shifting all over the place. Clearly, either its lack of ability to stay firmly in place, or the motion of it slamming into its mounting points was causing a persistent misalingment, of course which I was eating to fix every time.

After the alignment, the steering wheel is still cocked off to the left, a position it took the last time it shifted itself out of alignment. They claim it's been centered and it's just the road crown. But if the road is crowned downhill to the left of me, the wheel should be countering to the right, no? Whatever, it's a characteristic that was not there before.

The car was sitting too high for sure, since after the sway bar repair, I drove it and the front knocking/play in wheel/vagueness and wandering was gone, but the jerky handling remained. So the air suspension must (?) have been compensating for some geometrically-implausible condition due to the swar bar mucking things up. It drives 95% better, the wheel angle being the last 5%.

Oh, and my tech replaced the "dogbones" as a "courtesy" he said (CPO normally would not cover), saying they are an updated design now, with some boots around them to lock out corrosive elements. I didn't get a firm answer as to whether they were frozen or not, but they were original.

So, after 4 dealer appointments in 8 months, 3 round-trips to the latest one to get it properly tested, compared, diagnosed, and fixed to my liking, here we are. I like my tech, who is the foreman. I think he really hadn't experienced these northern-car issues at this southern dealership, and that's fine. I do not plan to buy another northern car because truly, MBCPO is not as stringent as I'd hoped.

The bigger issues lies herein. After 7 benzes from 83-08, 3 of which were CPO, 1 of which was Starmark, this will probably be my last Benz unless I win the lottery and can justify a new SL that I buy and trade after the warranty runs out, or I can find and buy the "survivor" original paint and spec 92 500E I want.

Mercedes wrote the book on used warranties what, 30 years ago? My 97 C230 for $13k in 2004 had a suspension squeak. The dealer promptly replaced every last piece of rubber and control arms up front within a month of me buying it. It ended up being tighter and better at 190K than at 60k when I bought it, and if I'd know where MBCPO was heading, I probably would have kept it as my last Starmark example. It was just a great car, largely because the warranty kept it in such good shape.

Enter CPO, which Hyundai and Ford have, and it's like MBUSA is trying to "dumb it down, and tart it up" at the same time. They want to give you unlimited mileage on the warranty (which no one will ever use), but in reality, they don't want to cover ****. On a C class, I get the royal treatment in 04. On a GL, I have to beg, plead and manipulate to get something other than "greased and coated" bushings. What a joke.

MBUSA - are you listening? You would think the initiator of used certified would want to stay ahead of the crowd. Now that everyone has CPO, they should be further differentiating themselves, not trying to fall to the others' levels. I don;t get it.

I always wanted a Cadillac as a kid, Maybe now it's time. I feel so much less stress driving my Focus SE Sport than the GL, because the Focus just runs and handles like a dream with no problems, reminds me of the old GTIs/Jettas from the 80s. Light, solid, and trouble-free. Every time I have an issue on the GL, I tense up and feel dread. I used to not feel this dread, because I know MBUSA would take care of me. Now, when something goes wrong on the GL, I have to psych myself up for a fight.

All the while, MB continues its trek downmarket. I guess the plan now is to build crap like the CLA and GLA, getting people used to a Toyota in German clothing and level-setting their expectations for downmarket warranty service when they want that new E class in 10 years. Then there's us oldtimers (and I'm not even 40), who grew up with 126s and 129s and 124s and even 202s, that were built by the engineers and BACKED by the engineers.

It's hard to even want a Benz anymore. At least a new or CPO one

will_w204

So......the nest question is, why is the steering wheel still cocked off to the left at about 15* on level straightaways? At the 3rd alignment, the wheel had been set straight and was fine. When all this latest drama began happening and it went "out of alignment" again, one of the characteristics was that the wheel was suddenly cocked off to the left when driving straight.

Parts replaced, 4th alignment done........tech says "oh it's just the road crown. Have you owned an SUV before?"

The gall! Yes, I've owned this one for TWENTY FIVE THOUSAND MILES, I think I know how my damn truck drives by now don't ya think?

It's driving me crazy because I keep having to make adjustments while attempting to track straiight

will_w204

https://mbworld.org/forums/gl-class-...-08-450-a.html

Subthread posted above.

So here's the deal! It's fixed! Initial issue resolved PLUS feels better than it has since I've owned it. Like everything else on this PA CPO car, there is surface rust underneath. Car ended up being totally deflated on the left front, so I got it MB-RA's on a flatbed. My main-man tech said it PASSED the leakdown test, as it has been doing, but he decided to tear into the left strut. Bingo. Rust and corrosion. he thinks the airbag was getting impeded/deflated(?) by internal rust. Anyway, was replaced, plus valve block, plus alignment, PLUS lowered the car to minimum spec and I tell you what, it doesnt bounce and bob anymore, steering wheel completely straight, and handles like a car half its weight.

I will never buy a northern car again, CPO or no CPO, however at this point the entire airmatic plus front aluminum has been swapped, so I think I'm good (maybe)