My rear wheels (still) tilt in like this - \ / need advice...
 

Good evening,

My rear wheels have had about 1.5 degrees of positive camber for the past year - and I've been trying like heck to get rid of it. Here's what I have replaced in the rear end:

-shocks (last May)
-spring pads - now have 9mm's (last May - started with 19mm's)
-subframe mounts (last June)
-diff mount (last June)
-sway bar links (last May)
-springs (today - ones I too out were different than the OEM's I put in)
-(and rear axles too, but that shouldn't matter here - Feb '07)
-aligned by Indy last may, and checked again this past Friday

After all of that, Im right back to where I began - about 1.5 degrees positive camber when I should have zero. Very noticeable when looking at the car from the rear.

What now? Start looking towards the front possibly sagging, raising the rear? I always see our cars with sagging rears - I haven't seen anyone on the board have this opposite issue.

Any advice much appreciated :o . I have spent a lot of time on this one so far. Oh how I long for no camber...

Thanks,
dd

ps - This is a continuation of an earlier thread - I have summarized most of it in this post already, but the original thread: http://www.peachparts.com/shopforum/showthread.php?t=182291&page=5&highlight=rear+wheel+tilts+adjust

Spring pads height
 

If you started out with 19mm and reduced to 9mm, it seems to me that that is part of your problem. As I understand it, camber is adjusted on these cars by INCREASING pad height to correct excessive negative camber. It seems you went the wrong way, you decreased height rather than increased height. What does those pads cost?

BenzDiesel

You must have springs that are too tall.

The front cannot make the rears have too much positive camber.

The simplist solution is to add weight to the rear.

You do have your spare in there don't you?

Tom W

BenzDiesel,

I think its the opposite. Think of the thicker pad extending the distance between the body and the control arm. More distance = more positive camber.

dd

Tom,

Thank you for the reply.

The springs I put in today are the Lesjesfors available on this site - and have the correct mercedes PN stamped right on them. I think these were OE. Im sure they are correct.

Springs I just took out had same ire size a the OEM's, but had half a turn more wire. Their only marking was 4 red slashes. No MB part # or anything like that.

Spare tire is in the trunk. All aspects of loading the car are correct. Full tank vs. empty tank hasn't seemed to make much difference. I need to add about 75 lbs of weight to the very rear of the trunk to equalize it.

Any other thoughts? I really want to fix this the right way and find out why its messed up for my own education and sanity.

dd

Oh, sorry I missed that you put in springs. It may take a few months of running to get it all to settle in an reach the correct heights.

I would put the 75# of ballast in there and run it and see if it does not settle in to the right height.

Tom W

Positive rear wheel camber is really rare, dieseldan
 

You will have to read the manual on how Mercedes recommends reducing rear wheel negative camber. They don't even talk about positive camber and is probably due to hardly anybody ever experiencing positive camber, most always negative camber where the top of the wheels lean in toward the body. Also, a whole lot of Mercedes engineering doesn't make sense when you try to logically guess at what is going on. Its almost like they go against common logic to get to the end result, which calls for a very high level of intelligence to understand and then work on these cars. It causes a whole lot of frustration as well, until you begin to think like they do.

BenzDiesel

add a wvo system with a 15 gal tank in the trunk, and keep it full.... or rip it all out and put in SLS :)


If you have the FSM, there is a good chart on what springs were fit to which car with which options. they are ID'd by blue/red stripes, etc..... section 32-010

if you dont have it, email me, I could send a copy.

I have the same issue with my car, slight positive camber when empty. I am sure if I could afford to actually fill my fuel tank all the way up:(, the added weight might help. When I throw a couple of children in the back seat it is much less pronounced, if not eliminated entirely.The tires are wearing evenly, and it seems to handle fine. But I will say it is one of those things that I can't help noticing everytime I look at my car.

Than you for the replies.

I have just gone through the service manual - (thanks Mo):

Relevant articles if anyone should read this in the future are:
32-010
32-230
32-240
32-250

For 123.133 (82-85 300D USA) cars the rear spring PN is 123 324 36 04. I had one with red slashes, indicating it was a 'short spring', and subject to use with three-nub, or 19mm spring pads.

I think I started with correct rear springs and spring pads. I now have verified that I have correct springs and shorter than stock spring pads, meaning I should have excess negative camber if anything.

As t walgamuth suggested, Ill ballast it and see how it goes. But, since I have come up with the same results following replacing a lot of stuff, I am skeptical that it will change (until the new components wear out :-) .

Are there any safety concerns or major tire wear concerns running with this positive camber?

The only other thing I can think of is the new CVJ reman axles...but..,I cant see how this would affect it.

Tom - why would the front end's not affect the rear somehow?

dd

Just as an update...

Re-checked tire pressures and went for a few mile drive.

No change in camber.

Looks like I need to get my hands on some worn out springs :-)

Designed to place your dead mother in law in the trunk?

Thanks... I'll be here all week...

[QUOTE=dieseldan44;1830864]Than you for the replies.

I have just gone through the service manual - (thanks Mo):

Relevant articles if anyone should read this in the future are:
32-010
32-230
32-240
32-250

For 123.133 (82-85 300D USA) cars the rear spring PN is 123 324 36 04. I had one with red slashes, indicating it was a 'short spring', and subject to use with three-nub, or 19mm spring pads.

I think I started with correct rear springs and spring pads. I now have verified that I have correct springs and shorter than stock spring pads, meaning I should have excess negative camber if anything.

As t walgamuth suggested, Ill ballast it and see how it goes. But, since I have come up with the same results following replacing a lot of stuff, I am skeptical that it will change (until the new components wear out :-) .

Are there any safety concerns or major tire wear concerns running with this positive camber?

The only other thing I can think of is the new CVJ reman axles...but..,I cant see how this would affect it.

The only way I can imagine that the front could affect the rear is if you had a lot of extra weight up there ahead of the front axle line which lifted weight off the rear.

The other thing I thought of is that you could have bent one or more parts on the suspension. Have you actually measured the camber to verify that you have this positive camber?

The positive camber would cause less grip in a corner, possibly.

Tom W

Tom,

When I had the vehicle aligned last May, they measured 1.47 degrees positive camber on the rear wheels. FWIW, the spec is 0 to -2 degrees. Ill try measuring again the next time Im in the garage with a level.

The two rear wheels are toed in exactly the same, and I haven't done anything I can possibly think of to somehow bend the subframe or CA's. I can't imagine I could have damaged the rear wheels in exactly the same manner.

Thank you for your continued thought on the subject...I know at some point there will be an ah-ha moment somewhere. There has to be, something is wrong.

Im ready to offer a reward for the root cause :D

dd

wheels
 

Sounds like Someone put in a wrong size bushing in back of the diff. Make sure you have the stock rear end and axles and triple check the rear bushing part numbers legnth etc. It could be that the last 2 bushings were too short and you need a longer one.
Sounds like a parts problem.

Mr. Shark, could you kindly provide a bit more explanation of where these bushings go that you feel may be causing the trouble?

Tom W

Isn't it that if a spring has more wire than another of identical height and wire thickness, it'd be a softer spring? So if you removed the one with more "wire" then that means you got stiffer springs in your car, that explains the positive camber. Just a thought.

edit: Nevermind, I just reread and it said you had the + camber prior to the new springs. Maybe something's wrong with your control arms?

Shark,

All of the bushings I can think of -

Diff Mount - replaced, I am sure of the part #,bought it from dealer
Subframe bushings - replaced, bought from this site, Ill recheck boxes
CA bushings - have not replaced, but look good. I don't think those would affect the camber.

dd

I just fixed this on my 300D
 

Some idiot actually had different springs, one blue, one red in there with 3 dot pads. I pulled a matching set of red springs with their 2 dot pads from the junkyard. Now it sits level and the camber looks normal - it may need to settle a little, but i just drove it around the block.
Visually, I could tell no difference in the spring coil diameter or height red vs blue, but the red springs must be stiffer.

They had a block wedged in the softer spring to try to level them out side to side too.

dieseldan44, perhaps it's time to back up and ask really dumb questions (I'm the one that's not that smart, by the way):
1) how was the camber before you started replacing parts?
2) how was the tire wear before you started replacing parts?
3) rear "sagging" before you started replacing parts? Measure rear and front height before replacing parts?
4) did you do any front-end work in the meantime?

I'd take a good gander at the rear trailing arm bushings- I believe you said the were not replaced??
if the inner were wore out, it may cause your issue. or if someone put eccentrics in there incorrectly.

dabenz - to answer your great questions...

1.) I *think* it was off from the time I acquired the car. I didn't notice it at first. The only parts I replaced before I noticed - rear axles with CVJ remans and the sway bar links.
2.) Rear tires are not worn to the eye. I have driven the car about 1500 miles since the axle replacement.
3.) I didn't measure before I started replacing stuff - I started replacing rear suspension stuff after noticing the positive camber in the rear last April, after the rear axle job. The rear end was never sagging.
4.) Replaced tie rods, and had indy replace FR ball joint. Indy then aligned. Front tires at the time had too much negative camber and inside wear. Front wheels are now perfect. Indy said the front end is tight and fine (except steering box, but thats another story for another time :-) ).

I really like what these questions possibly point toward. If the rear wheels don't have big time wear on the outside, then it would lead me to believe:

1.)I created this camber situation during my rear axle job somehow
2.) OR the problem was created recently before I acquired the car since the tires are not badly worn.

I did the rear axle job by the FSM and it went without a hitch. How the heck could something have gone wrong there?

Thank you for the continued thought,
dd

They look equally old. They don't look worn out, but they were not done recently. How could I tell an eccentric from a normal one?

Eccentric will have a bolt off center. Who installed the springs? Are the seated properly?

Me :) I think they are seated properly (how can I tell for sure?). Would seated properly mean putting the end coil snug against the indentation for it in the CA's spring cup? The spring pad on the frame floor has all nubs showing, everything looks OK.

As an aside, I confirmed tonight the springs I took out are the original correct springs. Red slash springs with the mercedes star and the correct part # for them according to the FSM. My car had the correct stock (26 year old) spring setup and was exhibiting the positive camber.

dd

The only adjustment for camber in the rear is spring/spring pads. I suppose its possible that your center carrier could be warped, fixing that.............

excuse my ignorance, but whats the center carrier? is that what the diff mount attaches to?

dieseldan44, I'd quit worrying about the "flexible" axles. Your trailing arms are cocked - that's the issue.

Springs, like us, get tired with age. May have the correct unsprung length but can't carry the weight, meaning they squish too far and pull the tops of the tires inward. Which isn't your issue, providing you have the right spring/pad correctly installed. Shocks don't carry weight - they keep the springs from bouncing.

Put a small block of wood on top of a floor or bottle jack, then gently push up on the fronts of the trailing arms and watch for excessive "give" in the bushings. Isn't much room to sqeeze yourself into. If I'm pulling springs then I'm changing those bushings. Be a good idea anyways at this point.

Trailing arms mount to the wishbone/center carrier. Wishbone mounts to car unibody in front. Correct parts/installation? Miss a shim? Wishbone mounts to differential in rear. Differential mounts to car unibody. Correct differential mount/installation? Shims?

Rear sway bar isn't supposed to carry weight - it just keeps things from getting too mushy back there.

Was the car in an accident? This may affect the wishbone/unibody alignment if the unibody is bent. The wishbone or trailing arms may have been bent by an accident or jack/jackstand. The unibody may be bent at front wishbone mounts or at differential mount from corrosion or many years of road pounding.

Bottom line: if the parts/installation are correct then you're going to need to shim something or live with it. Your fuel system will thank you for keeping the fuel tank full, by the way, and that's a few hundred pounds the rear end was designed for. One step at time and measure that camber/toe in before and after each step - you can do this at home. Remember to roll the car after putting it back on the ground.

dabenz,

thank you for the advice. ok, no more worrying about axles - makes sense.

I will try pushing up on the front of the CA's as you described and report back. Ill also do another inspection and post some pics. Pictures could say 1000's of words here.

Where are there shims in the system? I know if the spring pad shims - where else?

Car has not been in accident to my knowledge. Carfax is clean. No signs of any major repairs anywhwre. No rust - Texas car (hence the name, rust free is quite the commodity here).

Thank you, pictures are on their way.

dd

Pic #1 - view from up close, with the level. Other wheel is the same.
Pic #2 - from rear, tough to see
Pic #3 - CA bushing
Pic #4 - another CA bushing
Pic #5 - general diff area (that flash rust was from *one drive* in salt on the first day of winter when I got caught - amazing)

From my inspection I didn't see anything remarkable. No damage or worn spots or signs of funny business etc. I was hoping I did something like put the diff mount in backwards - but no.


dd

the first pic looks like the tires are wearing on the inside anyways. recent tire rotation??
or were those always on the rear??


If I did not have issue's w/ wearing out tire's, or pulling, I'd let it be.

Those tires were on the front until a week ago - just rotated.

dd

IN pic 3, the black line looks like a crack. Is it a crack or a seam?

then I'd say its about time for some front end work- how'er yer balls?(balljoints)

Ball joints are good and recently replaced. Tire wear was created by PO not paying attention to the front end, and what I think was a bad alignment. One ball joint was also cracked and bone dry.

Front end is tight, correct and aligned.


dd

It kind of looks crack-ish, but it is indeed a seam between the two halves of the wishbone. I thought the same thing when I saw it the first time, followed by heart palpitations, then relief when I realized it was the seam :-)

reply to question
 

Picture #5 is the part i was talking about.
I have been told that there are different sizes for the support bushing.
It could be one of those things where the dealer's computer says one thing but it was an off year or a "friday car" .
I would be real curious to see if you would unbolt the 4 bolts there and jack up the car in the rear and see if the wheels straighten out.
Or stick a 1" block of wood inbetween and let it down for curiosity sake.

Shark

dieseldan44, that needs fixing, providing the fuel tank is full. The first thing I'd do is get an el-cheapo tire tread gauge. Measure and write down the measurements across the treads in two or three places - all four tires. Make this a monthly drill. Then take some side pictures - I'd like to see how the car sits and how the rear tires are positioned in the wheel well. Photo #1 looks like a squished differential mount, lacking any other information.

Did YOU measure the rear wheel toe-in or did you take the shop's word for it? Very strange that you have this much camber with zero reported toe-in. My gizmo is just a stick with a couple of bolts at the end - kind of looks like a very short letter "U." Double nut the thread side of the bolt and epoxy magnets on the thread ends of the bolts. That and string and sidewalk chalk is all you need. If you can change springs and bushings then you can do the alignment.

Then it's time to e-mail Phil and Roy. You need the car's year and model, body and engine numbers and the numbers off the differential and differential mount. They need to gin up a list of differential mount part numbers - yours and the numbers that straddle your car in make and year. Could be you got the wrong part or the wrong part in the right box, or somebody changed the differential at some point in time. Same drill with the front subframe (wishbone) mounts. Reference this thread so they can see what's going on. You do buy parts from these guys, right? It's what keeps this "free" web site going.

To answer your other question: the guy in the mirror provides the shims if something is bent out of shape.

dabenz -

thanks for the reply.

i took the shops word for it on the camber amount. don't know about toe in officially, but by eye they look a bit toed in. ill make up a jig to measure it.

The diff mount is a brand new part from the dealer :-/

I have an appointment bright and early tomorrow morning with the vintage M-B specialists in my area. I have heard good things about them, and the tech I spoke to last week was great. Hopefully by looking at it an experienced eye will be able to spot something - like Im sure many folks here could if they saw it on a lift.

Ill report back with the results of tomorrows adventure. I really don't want the diagnosis to involve the words 'bent' and 'subframe'.

dd

Try adjusting the track rod (In the front suspension) longer. What it will do is
make more of the weight of the engine to the rear of the car. It worked
on a 300SD. You might have to lower your front suspension to do that
(I actually cut six inches off the front springs), but the result
is worth it.

I don't see how you could move the front wheels enough to impact this situation significantly.

Tom W

I don't see how you could move the front wheels enough to impact this situation significantly.

Adjust your track rod 5 turns(Going longer), your SD would look like
a preying mantis, you would need to a wheel alignment after you do
this. I just use strings for the alignment.
We lowered the front and raise the back on six SD's, this is not a
hypothetical suggestion.

Well? Do we have a happy ending?

YOu moved the front wheels at most 1/2". How much did that lower it?

Tom W

A moderately happy ending thus far. Swapped rear springs, again, with 9mm pads. The camber at rest was better.

Put 50lbs in the trunk and its now fine. Just filled the tan, Ill try taking the 50lbs out and seeing what happens. The handling on the highway is a little more sway-prone than I would like, but I think that has to do more with a loose steering box than the rear end. Everything in the rear is new.

Either way, I am now driving the car daily and not worrying about it. Ill keep an eye on tire wear or anything weird.

My original question stands as to why this could be happening in the first place. The MB specialist was quick to blame the reman axles as potentially being slightly too short and pulling the wheels in. My subframe is definitely not damaged - the MB specialists and me have looked it completely over and its fine. So theres not much left other than the axles in the rear thats not stock / OE replacement.

So, is this a happy ending? :D

dd