Ride quality suddenly lacking.

[feeshta]

Recently my car has developed an issue with ride quality that I am trying to troubleshoot. I do know that the front Sway Bar is rotten and needs replaced, so I am planning on replacing both in the near future, but I can't see how it would cause an issue like I am experiencing. the issue there is rust bubbling inside the passenger side bushing that has completely changed the shape of the bar to something quite different than round.

Basically I am now getting a much sharper impact from sharp edged bumps, a feeling of reverberation that was not there before, and I am feeling bumps that I never felt in the past. I could be driving down a glass-smooth newly paved road, and the ride still feels bumpy. It also seems to get worse the further you drive the car.

A quick bounce test of the shocks reveals nothing out of the ordinary, 1.5 bounces all around, but I am having trouble trusting that. The car has 120,000 miles on it. Suspension has been refreshed front and rear, Ball joints, control arms etc, but the shocks are original. Refresh seemed to make the issue worse if anything.

I did recently have to replace the drive shaft CV joint, and in the process of doing that I made a mistake that resulted in having to replace the differential input flange. It makes me wonder if something could be out of whack with the diff now, since torqueing the flange down is apparently a bit tricky. What would the syptoms be if I got the torque value wrong there?

[240sxguy]

Bounce test only works sometimes. I think you're in need of new shocks.

[16valex]

Feeshta,

I think you skipped the most important part of your suspension which is strut and shock.
When your strut is old and soft, it loses its damping capability so the spring has to take over by itself this is what you don't want to have, you want both spring and strut working together.

Try some new Konis I heard good thing from them, I wouldn't go with Billies since there're so many issue with them lately.

But what the heck you may try Monroe if that fits the budget.

[feeshta]

Feeshta,

I think you skipped the most important part of your suspension which is strut and shock.
When your strut is old and soft, it loses its damping capability so the spring has to take over by itself this is what you don't want to have, you want both spring and strut working together.

Try some new Konis I heard good thing from them, I wouldn't go with Billies since there're so many issue with them lately.

But what the heck you may try Monroe if that fits the budget.

The long term plan has always been to replace the shocks and I had settled on Koni. I'm just working my way through things as I can due to some unforseen and ongoing medical bills. Thank god I have insurance or I would be in debtor's prison by now. I suspected a shock issue, but there is no visible sign of failure from under the car and the bounce test seems fine. any other more precise way to test them other than take them off the car?

I think I will go with lowering springs while I am at it, as I don't like the reverse rake the car has right now. I'm not looking for much of a drop though, basically I'd just like to bring the front down even with the rear. Anyone have opinions on what works well with the Konis?

[16valex]

but there is no visible sign of failure from under the car and the bounce test seems fine.

You can't go by bounce test or visible sign.
But if you try to bounce and the car bounces it's bad, it should not bounce at all, it should be very hard to press down and no bounce.


I think I will go with lowering springs while I am at it, as I don't like the reverse rake the car has right now. I'm not looking for much of a drop though, basically I'd just like to bring the front down even with the rear. Anyone have opinions on what works well with the Konis?

Reverse rake! I like a little rake but definitely not reverse rake.

I don't know what work well with Konis but I know Geezer likes OEM sport springs with Konis. If I were you try to find a set of OEM sport springs and Konis.

[Graham E39 528i]

With my billy sports you can't push the car down at all!

Sent from nexus 7

[feeshta]

You can't go by bounce test or visible sign.
But if you try to bounce and the car bounces it's bad, it should not bounce at all, it should be very hard to press down and no bounce.



Reverse rake! I like a little rake but definitely not reverse rake.

I don't know what work well with Konis but I know Geezer likes OEM sport springs with Konis. If I were you try to find a set of OEM sport springs and Konis.

It's on factory sport springs now, and they are what results in the reverse rake. The gap in the front is about an inch bigger than in the rear.


With my billy sports you can't push the car down at all!

Sent from nexus 7

It's not particularly easy to push the car down on mine either, but when you do, you get the spring back up, and then back to center like I am used to seeing.

How do you like the Bilsteins, and what springs do you have them paired with?

[andre14]

Suspension has been refreshed front and rear, Ball joints, control arms etc, but the shocks are original. Refresh seemed to make the issue worse if anything.

I'm thinking this doesn't sound right. You're supposed to tighten down suspension parts (mostly the elastic bushings) with the wheels on the ground. I think the idea is that the bushings should be in the resting position with the car on the road. did you do that?

[feeshta]

I'm thinking this doesn't sound right. You're supposed to tighten down suspension parts (mostly the elastic bushings) with the wheels on the ground. I think the idea is that the bushings should be in the resting position with the car on the road. did you do that?

Yes, and the car has been aligned since then as well. I work on a military base and have access to both body and wheel on lifts.

[Graham E39 528i]

It's not particularly easy to push the car down on mine either, but when you do, you get the spring back up, and then back to center like I am used to seeing.

How do you like the Bilsteins, and what springs do you have them paired with?

They are fantastic (but very aggressive). They can't be that bad, my girlfriend wants me to put them on the e38 she's looking at.

I have Vogtland springs.

PM me if ya want more info. Good Luck!

:)

Sent from nexus 7

[larrym3711]

I tried to do a. "Bounce Test" on my 540iA Sport and it was kinda funny. Applying my full weight (170 lbs) very quickly on both the front and rear did almost nothing! Ok.. It did move the body a little bit....,but to call that action a "bounce" would be totally wrong. It does just return quickly with no bounce of any kind!!

larrym3711
2001 540iA Sport

[Graham E39 528i]

I tried to do a. "Bounce Test" on my 540iA Sport and it was kinda funny. Applying my full weight (170 lbs) very quickly on both the front and rear did almost nothing! Ok.. It did move the body a little bit....,but to call that action a "bounce" would be totally wrong. It does just return quickly with no bounce of any kind!!

larrym3711
2001 540iA Sport

If I tried that with my 220lbs, my fenders would be toast!

:ar15firin

[f355spider]

Recently my car has developed an issue with ride quality that I am trying to troubleshoot. I do know that the front Sway Bar is rotten and needs replaced, so I am planning on replacing both in the near future, but I can't see how it would cause an issue like I am experiencing. the issue there is rust bubbling inside the passenger side bushing that has completely changed the shape of the bar to something quite different than round.

Basically I am now getting a much sharper impact from sharp edged bumps, a feeling of reverberation that was not there before, and I am feeling bumps that I never felt in the past. I could be driving down a glass-smooth newly paved road, and the ride still feels bumpy. It also seems to get worse the further you drive the car.

A quick bounce test of the shocks reveals nothing out of the ordinary, 1.5 bounces all around, but I am having trouble trusting that. The car has 120,000 miles on it. Suspension has been refreshed front and rear, Ball joints, control arms etc, but the shocks are original. Refresh seemed to make the issue worse if anything.

I did recently have to replace the drive shaft CV joint, and in the process of doing that I made a mistake that resulted in having to replace the differential input flange. It makes me wonder if something could be out of whack with the diff now, since torqueing the flange down is apparently a bit tricky. What would the syptoms be if I got the torque value wrong there?

Very likely shocks/struts and upper shock/strut mounts. But, what brand parts were used for restoring the front and rear suspension? It is not uncommon for certain brands of aftermarket suspension parts to quickly fail...in a surprisingly fast time period.

[bmac1996acc]

If I tried that with my 220lbs, my fenders would be toast!

:ar15firin


Yeah I was thinking the same thing.... dents :stickoutt

[andre14]

Yes, and the car has been aligned since then as well. I work on a military base and have access to both body and wheel on lifts.

Wheels maybe? Are you on stock rims? Did you rotate?

[feeshta]

Very likely shocks/struts and upper shock/strut mounts. But, what brand parts were used for restoring the front and rear suspension? It is not uncommon for certain brands of aftermarket suspension parts to quickly fail...in a surprisingly fast time period.

Everything is Lemforder except the front thrust arm bushings, which are Meyle HD in Lemforder arms.


Very likely shocks/struts and upper shock/strut mounts. But, what brand parts were used for restoring the front and rear suspension? It is not uncommon for certain brands of aftermarket suspension parts to quickly fail...in a surprisingly fast time period.

Everything is Lemforder except the front thrust arm bushings, which are Meyle HD in Lemforder arms.

On the way home today, I noticed something I had been thinking I was feeling for a few days but couldn't be sure of. And this is only the last couple days. The back end of the car is moving around quick a bit. When it was wet, I wasn't sure if it was due to the rear tires on the car being shot, I have new ones, but I'm stuck waiting on a part to put them back on the car and the hurricane isn't helping matters. Anyway, on the way home today in dry weather, I could really feel the back end shifting around when I hit bumps, and when I got off at my exit it was really noticeable as a slow, back and forth wiggle. The exit is a slow sweeping turn you can take at normal highways speeds.

I just had the alignment done a few weeks ago, and I'm starting to wonder if maybe something didn't get tightened properly. It's an eery feeling. I'm stuck waiting till next pay to replace the shocks, will have to put the car on the lift tomorrow and check everything.


Wheels maybe? Are you on stock rims? Did you rotate?

Right now the car is back on the stock style 32s. Rotation is not possible due to the fact it is on directional tires, and staggered sizes. The rear tires are completely shot, as I have been forced back onto the old tires after buying a new set of M-Par reps and having what I think might be a spacer issue. Right now I'm waiting on a new set of spacers to check if the problem was a hub-centric mounting issue. If not, the wheels and tires are going back for a refund, and I will have to get the style 32's refinished. I wanted to go same size all around for rotation purposes, but I can't be messing around with it too long.

[andre14]

I think it's best to take the car to an alignment shop that is familiar with non stock tire setups and obviously bmws. These days, with all this 3d/laser technology it's fairly easy to get a proper alignment from any shop that has one of those... when your car is bone stock.

[feeshta]

I think it's best to take the car to an alignment shop that is familiar with non stock tire setups and obviously bmws. These days, with all this 3d/laser technology it's fairly easy to get a proper alignment from any shop that has one of those... when your car is bone stock.

It was in bone stock form when I took it to the BMW dealership for the alignment. Other alignment shops said they couldn't do the job, but a coworker used to work there and knows one of the mechanics, so they did it as a side job.

[James39]

Sounds like shocks to me as well. Bounce testing might work on the rear of an old pickup truck with spongy leaf springs, but not so reliable on something with somewhat firm coil springs on all 4 corners.

Even if they aren't the culprit, it's time for them to be changed anyway.

[feeshta]

Sounds like shocks to me as well. Bounce testing might work on the rear of an old pickup truck with spongy leaf springs, but not so reliable on something with somewhat firm coil springs on all 4 corners.

Even if they aren't the culprit, it's time for them to be changed anyway.

Yeah, I know they need changed. Just wondering if there might be something else that could cause this. Don't want to spend a grand and still be stuck with this issue is all.

[98M3_4]

I would change your struts/shocks and get new/newer rear tires back on the car, and then go from there. Another thing to check would be your rear sway bar brackets, which are known to fail.

[topaz540i]

How cold is it? My summer tires are starting to exhibit flat spot syndrome until they warm up. Its been about 50-60f here in nj lately.

Time to order my dunlap 3d's

[feeshta]

I would change your struts/shocks and get new/newer rear tires back on the car, and then go from there. Another thing to check would be your rear sway bar brackets, which are known to fail.

Got my new spacers today. Will go in tomorrow and swap in the M-Par reps with all new tires again, but it now seems pretty obvious it's the shocks. It's steadily getting worse, and the longer the car is driven, the worse the ride gets.

The rear sway bar brackets are fine, I had them off a few weeks ago when I did the rear suspension refresh. They are in much better shape than the fronts, which were quite rusty. The bushings are probably shot, but I'm going to replace the sway-bars in the near future anyway, so I am not going to mess with them. The front passenger side sway bar bushing is completely toast, but so is the sway bar inside it, so that's the same situation.


How cold is it? My summer tires are starting to exhibit flat spot syndrome until they warm up. Its been about 50-60f here in nj lately.

Time to order my dunlap 3d's

It's been in the mid 50s here, but the tires on the car seem to be ok until it gets down below freezing in my experience. On the other hand, winter tires tend to wear like warm butter when the temp gets about 60, which is quite likely here until december at least. I will stick with the summer tires for the time being. The fact that it gets worse the longer the car is driven also steers me away from cold tires as a culprit.