Vehicle Rocking Back and Forth
#1
Member
Thread Starter
Vehicle Rocking Back and Forth
My newly acquired 2008 Acura MDX rocks left to right when going over uneven road surfaces. I know for a fact that the sway bar links are bad. The boots are torn and they often make a clicking noise when turning and going over bumps. I know a sway bar helps prevent body roll when cornering, but would worn links cause the vehicle to rock left to right when driving straight?
#5
Member
Thread Starter
Its in the body, like a boat rocking. Let's say you were sitting stationery in a boat, then the wake from another boat collided with your boat parallel to the left side. The left side would rise then fall, then the right side would rise and fall as the wake passed underneath. This is the same feeling when driving over uneven road surfaces. The steering wheel does seem to be overly sensitive as well, but I think that may be an alignment issue. Hopefully replacing the worn links and getting and alignment will resolve things. BTW, I just had both front control arms replaced, and this issue existed prior to that.
Last edited by mossman; 07-30-14 at 07:09 AM.
#6
Well, that's exactly what sway bars are for. I fixed my 1st boss Explorer, when he couldn't figure why the shad rolls to the side so badly. All it took was to glance underneath and notice a hanging down link.
Buy ones with zirks. Pack with grease and be happy.
For 08, I doubt your struts are bad. My 09 Ridgeline is basically same parts, and is rock solid.
If I were you, I'd have done SB bushings same time. They do have much to say with this too, as SB moves inside the bushing up/down a little bit, but because it's angular change, at the wheel it turns to be accentuated.
Buy ones with zirks. Pack with grease and be happy.
For 08, I doubt your struts are bad. My 09 Ridgeline is basically same parts, and is rock solid.
If I were you, I'd have done SB bushings same time. They do have much to say with this too, as SB moves inside the bushing up/down a little bit, but because it's angular change, at the wheel it turns to be accentuated.
#13
Because:
1. the sway bar rotates inside and rubs off rubber
2. squeaks.
Don't be confused. Also helps reduce cracks in rubber.
Haven't you noticed that factory SB is lubricated inside bushings? Some white stuff.
1. the sway bar rotates inside and rubs off rubber
2. squeaks.
Don't be confused. Also helps reduce cracks in rubber.
Haven't you noticed that factory SB is lubricated inside bushings? Some white stuff.
#14
Member
Thread Starter
This has to be the most expensive "good deal" used car I ever heard of Mossman.
Haven't you noticed that factory SB is lubricated inside bushings? Some white stuff.
#15
I've decided to view it as an act of charity--
#17
Member
Thread Starter
New sway bar links and bushings did not help. In fact I think it may have made it worse. I'm beginning to think its the tires. It feels like the sidewalls are weak. Iw as experimenting the other day on the highway and when I would jerk the wheel abruptly, I would get a similar sensation as if the tires were made of jello.
#19
Member
Thread Starter
They are only a little over a year old, so they aren't worn out per se, but I just think they are poor quality, or maybe just not suitable to my vehicle. I'm thinking of buying a pair of used Michelins and putting them on the front to see if the handling improves.
#21
Member
Thread Starter
Inflate the tires to max cold PSI.. Drive it and report back the results..
#22
Group Moderator
Sounds about right. How hard do you have them inflated now?
FWIW, this would be a test - you typically get uneven wear (more in the center of the tire) when you pump them up to max like this and keep them that way. As an example, many cars say 32 psi for the tires but I like a stiffer ride so I keep mine at more like 36. There was a time when I had them at 40 but that's when I got the uneven wear.
FWIW, this would be a test - you typically get uneven wear (more in the center of the tire) when you pump them up to max like this and keep them that way. As an example, many cars say 32 psi for the tires but I like a stiffer ride so I keep mine at more like 36. There was a time when I had them at 40 but that's when I got the uneven wear.
#24
Mossman, you got me on this one. I have never ever heard of tires causing anything of this nature. I am afraid, you are not quite well describing the symptoms. But this is very straightforward:
The left side would rise then fall, then the right side would rise and fall as the wake passed underneath.
and there are only 3 components that can cause this:
1. sway bar
2. sway bar links
3. struts
Unless you have air suspension, which you don't, and it's causing all this havoc. Or, you have very normal response from - now - well functioning suspension and you simply over react. Or terrain is like wave.
As a last straw, check on crossmember bolts. And control arms. Outside of strong side wind gusts causing lateral lean, there is nothing else that will cause this.
The left side would rise then fall, then the right side would rise and fall as the wake passed underneath.
and there are only 3 components that can cause this:
1. sway bar
2. sway bar links
3. struts
Unless you have air suspension, which you don't, and it's causing all this havoc. Or, you have very normal response from - now - well functioning suspension and you simply over react. Or terrain is like wave.
As a last straw, check on crossmember bolts. And control arms. Outside of strong side wind gusts causing lateral lean, there is nothing else that will cause this.
#25
I have never ever heard of tires causing anything of this nature.
Mossman, you got me on this one.
#26
Yeah, that's why I suggested checking on subframe/cross member bolts. Also, that is trailer, and towing, and this is SUV.
Donno. Maybe man happened to be out of luck completely, and has an out of round tires - on both sides. Chances slim to none, but who knows.
Donno. Maybe man happened to be out of luck completely, and has an out of round tires - on both sides. Chances slim to none, but who knows.
#27
Member
Thread Starter
Wouldn't a bent frame show up on an alignment? And what about excessive toe in on the rear with zero toe in the front? Wouldn't this cause the rear wheels to steer the car a bit when going over uneven surfaces? Perhaps this is what I am feeling. It's like the rear is trying to steer the car and the front brings it back straight so you get this rolling/twisting sensation. I apologize for the description, but this is something I have never encountered before so it is hard to describe. I'll be replacing the tie rod ends this weekend (because one of them is bad) and then taking it to the shop to have it diagnosed and aligned.
A quick recap for those that may be reading this for the first time:
Issue: 2008 Acura MDX with squirrely handling, especially over uneven road surfaces
Vehicle alignment (toe only): Front toe: 0.0° total, Rear toe: 0.26° total (0.13° left and right)
Other known issues: Passenger's side tie rod end has free-play.
Work thus far: Replaced front sway bar links and bushings and both lower control arms (vehicle does not have upper control arms).
Work to be completed: Replace both tie rod ends and get four wheel alignment.
A quick recap for those that may be reading this for the first time:
Issue: 2008 Acura MDX with squirrely handling, especially over uneven road surfaces
Vehicle alignment (toe only): Front toe: 0.0° total, Rear toe: 0.26° total (0.13° left and right)
Other known issues: Passenger's side tie rod end has free-play.
Work thus far: Replaced front sway bar links and bushings and both lower control arms (vehicle does not have upper control arms).
Work to be completed: Replace both tie rod ends and get four wheel alignment.
Last edited by mossman; 08-27-14 at 06:59 AM.
#29
Moss, you need to finally determine WHAT is it that you are feeling. It either tilts like a boat on waves, side to side, or snakes down the road, left-right.
Your alignment picture will cause snaking. Not tilting.
Your alignment picture will cause snaking. Not tilting.
#30
To ask an obvious question: Was the vehicle ever hit or messed up with a serious off road surface impact, before you bought it? Just wanted to confirm that there could be nothing related to poor frame repair or other bent suspension parts that were minor and not noticed and replaced. It can happen.
#31
Was the vehicle ever hit or messed up with a serious off road surface impact, before you bought it?
The car was rear ended from what I read....
http://www.doityourself.com/forum/bu...-out-deal.html
Let the buyer beware....!!!!!!!!!!!
#32
A tire starting to separate will cause a low speed sway, May not feel anything above 25, Have to look at tires very close for a worn spot usually in one place in tire. Rotating will usually make the car feel different but will still sway.
#33
Member
Thread Starter
I believe it is a bad alignment and I am feeling the car steer itself as shown in the diagram, which is causing a left to right swaying motion, which I initially described as a rocking back and forth.
#34
Member
Join Date: Apr 2014
Posts: 108
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Unless I'm mistaken, there is no "frame" on this vehicle. It is, of course, what Acura and Honda call a "unit-body" (otherwise know as "uni-body"). No big deal, but sometimes it's best to use the correct terminology.
Anyway, I'm starting to wonder if you might consider searching out another 2008 MDX that you can test drive (i.e. at a used car lot or dealership).
I say this because you seem to have experienced far more problems and issues with this vehicle than what I'd consider beyond average (for an Acura anyway). Therefor, I'm wondering if you might be "over-thinking" things a bit (I too have done this to some degree with used vehicle purchases).
Also keep in mind that some 4 wheel and all wheel drive vehicles tend to "hunt" somewhat while going down the road (especially older 4x4s). Not sure if this is the case here, but it's something to consider.
Anyway, I'm starting to wonder if you might consider searching out another 2008 MDX that you can test drive (i.e. at a used car lot or dealership).
I say this because you seem to have experienced far more problems and issues with this vehicle than what I'd consider beyond average (for an Acura anyway). Therefor, I'm wondering if you might be "over-thinking" things a bit (I too have done this to some degree with used vehicle purchases).
Also keep in mind that some 4 wheel and all wheel drive vehicles tend to "hunt" somewhat while going down the road (especially older 4x4s). Not sure if this is the case here, but it's something to consider.
#35
Member
Join Date: Apr 2014
Posts: 108
Upvotes: 0
Received 0 Upvotes
on
0 Posts
I'll also mention that the 2008 MDX has an "Active (suspension) Damper System that might be causing what you're describing.
Active Damper System | 2008 Acura MDX | Acura Owners Site
You probably already know about this system tho...
Active Damper System | 2008 Acura MDX | Acura Owners Site
You probably already know about this system tho...
#36
Member
Thread Starter
I'll also mention that the 2008 MDX has an "Active (suspension) Damper System that might be causing what you're describing.
#37
Member
Thread Starter
UPDATE: Turns out it was the alignment after all. I had the shop set the rear toe to dead center of spec. and equal left to right, which also corrected the thrust angle to essentially 0.0°. The front toe was corrected as well and the steering wheel is now nice and straight. No more odd behavior--it feels stable and straight now.
#38
Member
Thread Starter
Spoke too soon. Although the alignment helped, it still feels unstable. I believe it has to be the shocks. It does feel like I'm just riding on springs. Maybe I'll start with replacing the rears first since it is extremely easy and cheap--they are not coil overs.
#39
Member
Thread Starter
Okay, so I replaced the rear shocks this evening and there is a definite improvement. I'll therefore be doing the fronts as well in the near future. I'm wondering if it's a good idea to replace the strut bearings and/or mounts as well, or are these typically lifetime parts? Also puzzling is that the bump stops on the rear suspension (located inside springs) appear to rest against the bottom of the lower perch/basket/whatever it's called. Is this normal or are my springs sagging? Perhaps they are supposed to touch and compress with the suspension.
Last edited by mossman; 09-20-14 at 06:56 PM.