Left Rear Wheel Tilts a Bit
 

Just returned from a 70 mph drive and noticed no unusual noise, my good
neighbor, noticed the left rear wheel is tilted inward, in other words
the top of the wheel is tilted inward as the bottom is tilted outward by
a couple of degrees.
I jacked the car up and the wheel has no movement when I kicked the
top or sides, taking a quick peek underneath, it's raining in Boston,
saw no abnormals .....had the rear wheel bearings replaced about 6
months ago and just on big pot holes or angle approaches to the
driveway, would hear a slight tension sound coming from the rear
......Maybe it finally broke ...
Plan on taking a 400 mile trip this Friday, wear the tire a bit, but
am concern about causing additional sever damage... minor damage will
not bother me ....TIA

Bill
1981 300 TD

Couldn't that just be from the rear end of your car riding low or sagging?

I agree. Take a look at the opposite wheel. They are probably similar.

The lower the vehicle rides in the back, the higher the negative camber. Nothing much you can do about it unless you get the back end higher via the use of new suspension components and/or taller springs.

Take a closer look.....
 

Some years ago I had an '82 240D......it somehow managed to develop a crack in the ...I can't remember the exact name of the part, But....the big "V" shaped steel piece that the Axel Shaft assembly passes thru.....the crack appeared just under and a bit inboard of where the wheel bearing rests....caused the rear wheel to can't inward at the top....just as you describe......

Please check closely, this could become dangerous.....and a real pain of a problem on a 400 mile trip.....

Luck to ya....
SB

The right wheel is vertical and shows no sign of tilting ....
You do remind me when I had about 800 lbs in the rear of my wagon, and the rear covers the top of the wheels a lot ...but can not recall any tilting
the height difference today of the two rear wheels are about 4 inches or so .... so the left rear wheel is sagging .....
Sounds like no big problem to drive 400 miles and avoid pot hoes and the like ....TIA

Bill

1981 300 TD

Sounds like a failed hydropneumatic shock on that side??

Definitely. The left side is considerably lower than the right and the camber on the left side is significantly more negative.

It all fits.

Now that I think about it, it could also be a failed line to that shock, or perhaps low fluid or a failed pump or maybe a failed level detector switch. In any case, it could lead to some dangerous handling characteristics under some circumstances so I'd be a little reluctant to do a long drive without troubleshooting it.
The simplest method I have for testing the hydropneumatic shock system is to start the car while sitting in the driver's seat with one foot on the ground. After the engine starts, I can feel the car rise as the shocks are activated and then settle back down to the proper level. You can also use the rear view mirror and get the back of the car and a distant object in view and watch the rear rise as the system is activated. I've never done a comparison side to side.

So, what is the fair cost to replace the Hydropneumatic shock???? Too big of a job at this time of the year for me ....I thought it might be the sub frame or the Hydro shock .... TIA

Bill
1981 300 TD

is it as negative as this pic?
http://i3.photobucket.com/albums/y74...4/negcam-1.jpg

No, that is severe ..... never drive that car better to be towed to where you want to go.... mine is about 3/4 less than the photo... all tire surface is on the ground ...

Bill
1981 300 TD

Fastlane has the shock for $375. Labor shouldn't be more than a couple of hours I imagine. I'd do some investigating on fluid level and general function before asking for a shock replacement. I think it might also be a failed nitrogen sphere accumulator on that side. Does that side have any evidence of shock absorbing capacity and is there any evidence of a leak? Accumulator is only about $110.

the pic is of a modified 450SEL with air ride.. modified so it sits lower ^_^

I checked the fluid level,leaks, and the like looks fine....The nitrogen sphere accumulator on both sides have never been replaced since I've owned the car for 15 years .... What do there sphere do ?
Hit a bump in the road on the left tire and the rear followed about the same, no noticeable difference.
I like to ask about cost for a repair so when I go to the garage, I am prepared somewhat .....

Bill
1981 300 TD

All I can say is, check the rear control arm carefully. I had mine rust thru and crack. Rust started from the bottom 2/3 turn of the spring breaking. Wheel developed lot of negative camber. I'll see if I can find the pictures I took.

The accumulator is divided into two sections with nitrogen on one side and hydraulic fluid on the other. It provides the shock absorption. The shock is essentially just a hydraulic ram.
No evidence of a leak and evidence of continued shock absorption is odd. Does the system still go up and down as designed. Does it raise up when the start the car and level up when a load is put on the rear of the car?

Were the rear suspensions designed to tily like that so that the tires don't rub when loaded of traveling over undulating road conditions?

this post is right on.

i have replaced one of these on a 240d from rust. my daughter in law was driving the car and complained that the hubcap fell off. when i looked at it the top of the wheel was 2" in from the bottom.

i wouldnt drive it even around town until i examined the main suspension arm in the back for rust or cracks.

it is a large piece that is fabricated from relatively thin sheet metal. it derives its strength from its shape. the thinness allows it to be light weight to make for the famous mercedes ride and handling.

it still could be the accumulator or the strut i suppose but i wouldnt make any assumtions. and definately not a trip out of town.

tom w

all independent suspensions tilt as the springs are compressed, whether front or rear. this is so that when you corner, the compressed springs and tilted wheel cause the tire to keep perpindicular to the road for optimal traction.

in the early days of independent suspension this wasnt always true though. but that was back when most roads were dirt and tires werent much wider than a bicycle tire.

tom w

So it's happened to others as well....
 

Control Arm.....the big "V" shaped steel piece.....if yours is cracked as mine was, I would be very wary of driving it.......

SB

^LCA- me too, i replaced mine this spring- along with a all the rubber parts under there i could. used arms, everything else new.
also 2 new tires, as i ruined the other 2 driving around like that for a while. caused some pretty severe belt seperation in a pretty short time.
i had welded a new pan all across the entire bottom of the control arm out of 3/16 steel. but without removing the arm, i couldn't straighten it at all.

wouldn't recomend that to anyone, ;) but it did keep my DD rolling while i collected parts.

i got 2 LCA's for about $225, shipped from arkansas. i then wire wheeled them, coated with penetrol, and rattle-canned about 7 coats of primer and flat black. i had lots of time while i waited for wheel bearings and a socket. if you do need to order these, ask that they leave the hub assy's intact.:silly: , especially if they dont have the proper tools.
and may as well replace in pairs. when i got mine off, i took a 16 oz hammer to the other side. 2 swings and i had crushed the bottom in:eek:

overall, it costed me about a grand. new rotors,p brakes, wheel bearings, pretty much everything that was under there. and the tires. oh- i did it all myself, too.
heres a link to junkyrads nationwide.

good luck.

http://www.uneedapart.com/

i have replaced several of those arms. i paid from 75 to 200 for the used part and about 200 to 300 for my indie to install.

tom w

i have a 240 scrapper which is like that on the front, i know it is a bit simple , but the spring has sheared through about 2 coils from the top, completely snapped

"Does the system still go up and down as designed. Does it raise up when the start the car and level up when a load is put on the rear of the car?"
I have not put a load in the car to test the SLS. The car never raised after starting, if it did, my understand the system is loosing pressure and SL value might be bad.
This morning, when entering the driver door, my weight, 175 lbs, cause a steel tension sound ringing. It's like a spring under tension and suddenly the tension is released is the sound I heard. Making me think a broken spring causing the sag because the engine is off and weight cause a noise. Riding to and from work noticed the car bounce up and down on a bad rut in the road. I did a lot of zip-zags at low speed and up to 40 mph and the rear end did not force the direction of the car. The car feels safe to drive.
Tomorrow will look under the car for things suggested in this thread. Thanks for the help everyone.

Bill
1981 300 TD

Before I had the level control re-adjusted in mine, it made that same sound. After it was reset by a local indy to the proper height, the sound went away.