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View Full Version : 3 suspension related symptoms - help me diag this sh---y bucket



JuanPabloBongto
03-22-2013, 12:17 AM
Car:
2000 528it auto
Pertinent info:
4 brand new Sachs (oem) shocks, 4 new shock mounts, 2 new rear swaybar endlinks
front ctrl arms are good. 1 rear boot has a split, but it is stable (no play)
car is a daily driver, 17miles one-way to work and back

My lady's 2001 Ford Taurass is the Ultimate Driving Machine at our house.
We need to fix that.
I need YOUR suggestions and ideas on where to start for EACH OF THESE THREE PROBLEMS with my 528it:

1) Jiggly wagon butt
The best way i can describe this action is that it's the same ride a hoed-out wheelbarrow with a 5 yr old 20psi tire gives at the u-pull junkyard. So imagine that up/down wobble coming from the rear, as though you are PULLING the wheelbarrow over uneven ground. any disruption causes slight bouncing.
It shudders/bounces in a fast/tight oscillation when driven over seams in the highway @ all speeds.
When potholes/bumps are hit at cruising speeds, it BONKs over them. No sharp noises happen (no clunks, no thunks) but certainly the suspension is not doing the job somewhere.
It's almost as though the tires are overinflated, but when you check, they are not overinflated.

2) step-out / wicked oversteer bro
When the car drives over seams at highway speed, on gradual, large-radius, sweeping bends.... the back end stutters to the outside.
If i were riding a horse and experiencing this, I would believe that one of the rear horse hooves stepped on a branch that rolled us slightly toward the direction momentum was trying to take us. Unstable. I hate it.

3) Parkinsons by the traffic light
Whenever i come to a complete, gradual, controlled stop at a stop sign or stop light, the car stops, but the momentum does not.
I continue forward ever so slightly, and then the car jiggles to a standstill. like one of those springy doorstops that goes BOI OI OI OINNNNGGGGG.
Understand that the wheels are perfectly stopped, and yet I am a bobblehead until the car says i can cease.


The car is beautiful but it's driving me f---ing batty.
(I know that rear subframe bushings are suspects, but I don't think they'd cure all 3 insanities)
(it's too cold to DIY the rear suspension right now in MN so I'm going to load up on knowledge for a few weeks)

I've never wanted a Taurass so badly as when I drive this sh--box across railroad tracks or over a pothole.
I don't own any guns, or I'd need a carry permit so i could shoot myself in the face. I am going mad.

larrym3711
03-22-2013, 09:11 AM
Juan,

I am always somewhat surprised at the dedication of members to fixing problems with their BMW's. I understand you are knowledgable about mechanics on cars. That's good. However, it is not worth the frustration and wife-issues (!) to prolong problems if possible. I don't know about the area you live...but....at this point I would find an alignment shop for a "free inspection" and see what they say. My guess is they will say your rear end fittings (ball joints, arms, bushings, etc) are in serious need of replacement. Getting a "second opinion" seems the best therapy at this point to maintain your sanity!

larrym3711
2001 540iA Sport

Gumbi4u
03-22-2013, 11:27 AM
Juan,

I am always somewhat surprised at the dedication of members to fixing problems with their BMW's. I understand you are knowledgable about mechanics on cars. That's good. However, it is not worth the frustration and wife-issues (!) to prolong problems if possible. I don't know about the area you live...but....at this point I would find an alignment shop for a "free inspection" and see what they say. My guess is they will say your rear end fittings (ball joints, arms, bushings, etc) are in serious need of replacement. Getting a "second opinion" seems the best therapy at this point to maintain your sanity!

larrym3711
2001 540iA Sport


+1

Throwing money at the problem is not going to solve it. Throwing an expert that knows these cars is the key. Im going to say rear ball joints and one or more of the tires has an issue.

JuanPabloBongto
03-22-2013, 03:09 PM
oh, come on guys. Shoot from the hip, here.

I'm going to do rear subframe bushings myself, and while I'm in there, control arms all around. A trip to a pay mechanic ain't gonna happen before May because of other commitments.

I put some serious effort into describing the suspension activity as best i could, because i want to virtually stand around my car, speculating.

Now let's throw some darts... here I'll get you started:

"Sounds like that could be..."
"But I wouldn't be surprised if you needed..."

- - - Updated - - -


My guess is they will say your rear end fittings (ball joints, arms, bushings, etc) are in serious need of replacement. Getting a "second opinion" seems the best therapy at this point to maintain your sanity!
You're right and I should find a way to make time for a professional opinion.


Throwing money at the problem is not going to solve it. Throwing an expert that knows these cars is the key. Im going to say rear ball joints and one or more of the tires has an issue.
I'm going to need to throw money at it one way or the other. I have a little time to speculate and make guesses and try to learn something about my car, so I thought I'd make a thread about it.
All 3 issues i describe above are consistent across 2 sets of tires (winters and allseasons), but ball joints is a reasonable explanation for #2

Cyrix2k
03-22-2013, 03:49 PM
How many miles are on it?

remirokosa
03-22-2013, 04:10 PM
Sounds like my buddies m3 that needed trailing arms. It felt like the rear was constantly hitting ice going back and forth but the body was traveling straight.

JuanPabloBongto
03-22-2013, 05:00 PM
How many miles are on it?
160k
it's a wagon, so I'm going to do new rear subframe bushings no matter how good they look (i don't see any leaking fluid evidence but they're definitely older than i want them to be)

jstern
03-23-2013, 12:45 AM
160k
it's a wagon, so I'm going to do new rear subframe bushings no matter how good they look (i don't see any leaking fluid evidence but they're definitely older than i want them to be)

You can inspect the rear subframe bushings by removing the circular plates that support and cover the bushings. You have to raise the car on jack stands, support the differential with a jack (don't raise the car any farther), and remove the long bolts that anchor the bushings to the car. Do one at a time. If you can see cracks in the bottom of a bushing, the liquid has escaped and the bushing is junk. If you find one cracked bushing, you know all have to be replaced. Those long bolts need to be torqued to 106 ft/lbs.

If you go to the Beisan Systems website, there is an excellent DIY on checking rear ball joints. They say it's only for sedans but the wagon suspension is not that different.

Good luck