gtab55

Hi,

My parents own a 2008 GL 320 CDI that they dreamt of owning from when they saw it at the auto show. But what a piece of garbage vehicle it is. 19 appointments for repairs as of now and they are looking to trade it in on an Audi Q7 TDI this summer. The only thing that needs to be addressed before it's gone is this right pull that has been occurring since I was sitting in the passenger's seat on November 26, 2007 with my dad driving while we were heading home from the dealer. The dealer has said to have fixed this numerous times. Pirellis, Michelins, alignments, rotations, balancing, etc...the right pull has not been fixed. It is a 19" rim vehicle. The steering wheel seems to make a very faint click in it when you turn it to the left (which it has to be in order to go straight) and almost feels like it is disengaging something when you take it off of 'straight' and go to the left. I have read and hypothesized that it is the steering rack, but being that benzworld didn't like me, I decided to come here to see if I could help out my parents.

Pics of the steering rack boots: (Notice the difference in color for the rack boots)
RIGHT SIDE>>


LEFT SIDE>>


I also noticed the tags on the shafts for the CV joints were orange and white on the right and left sides, respectively. In the rear, the same is also true, except different sides.

Thank you for reading this and I would appreciate any help you could give.

vntgspd

Pulling to the right is common in vehicles without any "caster lead". This means that the caster setting on the right is 0.5 degree higher than that on the left. This counteracts the crown of the road.

Most dealers/alignment shops will tell you that there is no adjustment for this on the Mercedes. This is NOT TRUE! There is a special bolt sometimes called a crash bolt that will allow you to adjust CASTER. This is a common part for camber adjustment and most dealers only know about this. Don't confuse this with the CASTER adjustment that is found at the rear of the lower control arm where it bolts do the subframe.

Contact the dealer and shop to find out the alignment specs and whether they used this bolt. Even if it's "within spec" you can use this to increase right side caster (or reduce left side caster) to fix the pulling.

Note that other things such as tires or worn suspension can cause this too but your post indicates these things were all checked.

alx

a slight pull to the right is built-in most modern vehicles. the pull is amplified on most roads as they are sloped to the right to facilitate drainage.

i have been told this is to provide a safe veer to the right vs the oncoming traffic in case the driver falls asleep.

gtab55

So if I adjust the caster, will that cause the tires to wear out sooner than they will currently?

vntgspd

No, caster will not have any significant effect on tire wear. Improper tire pressure and toe settings are the fastest tire killers. Then excessive negative camber...

I've heard the story about the right-pull being a safety feature. Makes me laugh!
Put the car on a rack and if the caster number on the right is not greater than the caster number on the left (typically .25 to 1.0 degrees) then the car will pull to the right on 90% of the roads. The problem is that modern Mercedes have minimal adjustment and what they do have is not visible to the average mechanic (including some dealer techs). So, most will say they adjusted what they could and it's "in-spec".

Check this out for a quick tutorial on alignment terms

http://www.anewtoronto.com/wheel%20alignment.html

alx

Most perfectly aligned mercedeses will pull to the right on a perfectly flat road. Including brand new ones. I can tell you that from personal experience. And since numbers are numbers and if perfectly straight the car should track straight yet it doesnt- i think it might be dialed into the alignment racks. I have no other explanation. Laughing is optional

gtab55

OK, today I took it to get an alignment at a Sears Auto Shop and the service rep told me that the right front suspension was moving up and down while it was on the lift. He said the left side didn't move whatsoever. Also, he stated that the alignment was correct, but did not know anything about Mercedes specific specs, just what he had. The car is going in to the dealer tomorrow. I'm hoping this can resolved for the last time.

KrustyKustom

At the dealer the procedure for alignment involves a deactivation of the suspension, and checking the alignment at top of suspension stroke (extended) and again at highway level. Hopefully you have not had sears work on this car before, there is just too many special procedures.

You mentioned the Audi Q7 earlier as a next car. This vehicle is in no way a simpler vehicle, and tends to experience the very wide variety of reliability issues that are expressed on the GL/ML.

You want simple buy a chevrolet equinox.

chsu74

I can tell you from experience that you overpaid for a crappy alignment.

alx

then mercedes has crappy alignment racks at the factory and so do most dealerships :dunno:

vntgspd

I think it's important to clarify that there is a difference between a "good" alignment and an alignment that is "within spec"

Aligned within spec simply means that the numbers fall within the parameters that the engineers allowed given production tolerances and other factors such as wear. This doesn't mean that the vehicle automatically drives straight or wears tires evenly just because the numbers are between the goal posts! Most alignment shops work to this level of detail.

A "good" alignment is one that results in adjustments to the suspension to improve/correct vehicle dynamics such as handling, stability, tire wear, etc. Sometimes, like on the newer Mercedes, these adjustments do not come easy and so they are typically not done. It takes a dedicated shop with knowledgeable techs to achieve a "good" alignment. If you don't know of one, check with the racers in your area, they will know where to go!

chsu74

I did not have an issue with my car after a local dealership alignment. Tech's skills vary and its a crap shoot who ends up working on your car.

gtab55

Basically it has come down to this, if they tell me (I am the one taking the vehicle down) that it will fix the pulling when they do the $300 alignment, I will have them do it and pay them IF it is fixed. That is what is going to happen tomorrow.

mp0i

My GL was tracking (pulling) to the right so I had my dealer perform a four wheel alignment for about $150. They adjusted the castor during the alignment. Everything appears to be fine now.

gtab55

OK so my rep told me that the front sway bar bushings and serpentine belt to be worn. He wants to replace the belt and has recommended for the bushings to be replaced. Any help/suggestions?

vntgspd

What about the alignment and pull to the right???
I highly doubt worn sway bar bushings would cause that.

The serpentine belt is less than $30 and takes about 10 minutes to change. Always a good idea to keep them fresh but up to you if you want to pay dealer prices for it.

gtab55

He is going to be adjusting the castor bolt and install it because he says it never had one to begin with but did on the left side but not on the right. That will bring the alignment to $294 plus tax. The serpentine will be $220 including labor. We will let the bushings go until the next service or when we sell it.

vntgspd

$220 for belt and install? Ouch.

Too bad your not local, I would do it for $100.

Glad to hear they are addressing the caster by swapping to the adjustable bolt. Good luck.

gtab55

^^^ PM sent

gtab55

Here is an update:

The dealer replaced the fuel filter, the sway bar bushings (warranty), alignment, and the serpentine belt. It cost around $840, but let me tell you, this car drives and rides like a dream now. They made an adjustment to the Airmatic and it is simply luxurious.

Also, the left parking light is out. It has the bi-xenon setup so I was wondering if there is an easy way to change this out? I have a VW and I can change out most lights with that, but I'm not sure about this Benz.

EDIT:
Did some research and found that the ML required needle nose and looking at the manual. I have p;enty of needle nose but I can't look at the manual right now. Im sure if it's just a twist and pull job it can't be that hard.