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#1
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55 MPH violent shake W126
At first I blamed it on the old set of tires. New tires made it worse. It happens on the drivers front wheel starting around 55mph, gets so bad the car is almost uncontrollable. Slowing down to 48mph or making a slight turn left or right makes it stop. Left turns seems to solve it better than a right.
Quick inspection of the suspension parts when its jacked up off the ground show a slightly loose lower ball joint on that side. However, its no worse than the right. I've seen much worse. Tie rod ends are tight, shocks are not that old oem. I'm baffled. Also, it seems worse when going downhill, better when the tank is full of fuel so, the weight on the front has some affect. This problem just seem to appear rather quickly. I am the sole driver and did not hit any holes, curbs to do damage. I hate to dismantle the entire front end to find it. Any ideas? Right at 200K miles on the shaker. Mosty mine. |
#2
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you have to unload
the suspension to do a correct evaluation of the bad parts. i dont know exactly how to do that so i would take it to my favorite alignment shop and ask them to evaluate what needs doing. then if you do it yourself take it back there and have it aligned.
sounds like no time to waste. tom w
__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC] ..I also have a 427 Cobra replica with an aluminum chassis. |
#3
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I agree...a violent shake is not something to take lightly....you NEED to find whats wrong BEFORE it sends you into oncoming traffic or into a tree at speed.
__________________
Proud owner of .... 1971 280SE W108 1979 300SD W116 1983 300D W123 1975 Ironhead Sportster chopper 1987 GMC 3/4 ton 4X4 Diesel 1989 Honda Civic (Heavily modified) --------------------- Section 609 MVAC Certified --------------------- "He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche |
#4
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Quote:
Its strange that the problem appeared somewhat suddenly. Started out as if a tire was out of balance, got progressively worse so, I replaced the tires. Then it was real bad. I took it back for a re-balance and had them check the wheel. No problem found so we did a rotate just to rule it out. I'm going to pull the shock and have a look at it. Maybe an internal leak all the sudden in there. Proceed from there. I see a complete front end rebuild coming on. I don't see how anything could wear this fast. |
#5
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well
i used to think that if the spring was compressed you could test the ball joints by hand. but it is not that simple, quite. the pros use some kind of pry bar to check them i think.
tom w
__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC] ..I also have a 427 Cobra replica with an aluminum chassis. |
#6
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One of the members recently changed the steering damper on the front end. Magically cured a bad front end vibration when everything on the suspension and steering appeared normal.
He mentioned that the damper was effectively doing nothing. All the resistance to movement was gone. |
#7
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Check this stuff out....I had a bolt fall out (NOT GOOD!)
First Time....my diesel left me stranded (sorta) Be sure to look at the pictures... This is most likely not your problem but it is WELL worth checking....easy to not notice at first |
#8
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I know exactly what you are talking about. I swapped an old pair to the front of my sd for a temporary fix. The ones that were on there were pretty darn bad. I put them on and took off down the road and when I hit 50 there was a violent pounding vibration that shook the crap out of the steering wheel and didn't go away untill I slowed way down. I put the old crappier tires back on and it was fine. There was some play in both wheels when wiggled side to side so I put on some tie rods that I had, had an alignment and got new tires. It doesn't pound like it used to, but there is definitely some unpleasant vibrations going on up there around 60 mph. I was told that it is probably the steering dampener or wheel bearings that needed replacement. I'm going to take another look tomorrow.
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"spreading a trail of obnoxious where ever we go" 1981 300sd w/ 341,500 miles http://www.wecrash.com/pics/ddda_banner.gif |
#9
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Motor or wheels
Drive at 55mph then change to nutral and let engine rppm fall to an idle.
If the vibration goes away thenn the vibration may be coming from the engine. If this is the case set the valves clearances. I speak of this from experancing the same problems. |
#10
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Had the same problem...
At around 55mph, it felt like the front tires were "bouncing" up and down.. it was pretty scary when it happened. Slowing down made it go away.
One of the forum members here gave me three useful words of advice: BALANCE THE TIRES It worked.. Make sure to go somewhere that does high performance stuff (ie. somewhere that has a Hunter 9700 balancer). I went to a place that does work for the local BMW and Porsche clubs. Never had a problem since.. apparently the W126 chassis is VERY sensitive to improper tire balance. Neal
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'83 300SD 335,000km (207k) mi SOLD '87 560SL 163,000km (101k mi) SOLD '86 300SDL 356,000km (220k mi) SOLD '92 500SEL 250,000km (155k mi) SOLD '90 300SL 140,000km (87k mi) SOLD '01 S430 260,000km (161k mi) SOLD '03 SL500 167,000km (104k mi) SOLD '07 S550 4MATIC 235,000km (146k mi) SOLD '07 GL320 CDI 4MATIC 348,000km (215k mi) '13 GL350 BlueTec 4MATIC 170,000km (105k mi) '14 SL550 72,000km (43k mi) |
#11
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There are no front suspension parts that can CAUSE a vibration. If you have a tire causing a vibration, there are plenty of things in the front end that could WORSEN the vibration.
I would start by rotating the tires front to back and see if it changes. If it does, it's time to make sure you don't have a bent wheel and make SURE that the wheels are DYNAMICALLY balanced with no excessive road force variation (stiff spots.) Once you get the tire/wheels where they make no more vibration you can then determine if there is anything worn out that is exacerbating the vibration. It is possible that you have a bad motor mount or two. When they go bad and get the engine solid with the chassis, the vibration is unbelieavable, but at engine speed, NOT at wheel speed. Good luck, |
#12
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shake rattle and roll Finger rule!
You need tie rod ends ........ my 126 body did the same thing.
Loose suspention parts can cause the vibration you describe Do the finger test... very simple.... As you drive down the road ...Hold the wheel at 9:00 and 12:00 o clock. At the 12:00 position hold your index finger up. Observe your finger as the car shakes ....Up and down is ballance. Side to side is worn steering components.
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2003 SLK 230 (85000) 1999 E300 Turbo Diesel (388,000) 1991 350SD Turbo Diesel (185,000) |
#13
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Maybe a bad center bearing for the drive shaft or a host of many other items.
__________________
1981 300D 147k 1998 VW Jetta Tdi 320k 2001 Dodge Ram 2500 141k 1979 300D 234k (sold) 1984 300D "Astor" 262k(sold) Mercedes How-To and Repair Pictorials I love the smell of diesel smoke in my hair |
#14
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I'm with Larry on this one. If the wheel/tire was in perfect balance and round there would be no vibration for the suspension components to hold still.
However, I changed tires, re-balanced and rotated to no avail. The vibration is definately coming from the LF. Wheel shake is so bad it is dangerous to drive at 55mph. Whats that song..."I can't drive 55". LF tire bounces or wobbles violently. I think the oscillation is excited by perhaps a slight balance issue, sustained by worn suspension part(s). I'm not driving it. Have a look at it this weekend and report back. |
#15
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Well you said your lower ball joints are worn so start by replacing those. Check your inner tie rods as well.
Something is lose.
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1999 SL500 1969 280SE 2023 Ram 1500 2007 Tiara 3200 |
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