Lateral movement

[renz]

I have a 95 XLT with stock suspension. One thing that I have noticed on mine is lateral roll when going over bumps, especially at low speeds (driveways, parking lots). I have also noticed that this does not happen in some of the other SUV's. I know my in-laws does it was well. Is this normal? If so, can I do anthing to fix it?

Thanks in advance,

 

[GJarrett]

Can you define for us exactly what you mean by "lateral roll"? And does it happen when both front tires go over a speed bump, or when one tire hits it first (crossing at an angle) etc.?

Gerald
"Nerves of Steel; Brain of Chipmunk"
~~~~~~~~~
'99 Eddie Bauer 4x4 4.0L SOHC aka "The Jeepeater"
Mods listed in my Explorer Registry post 7/8/99
Dead Link Removed "What the heck is he doing out here in that thing?"



[This message has been edited by GJarrett (edited 03-29-2000).]

 

[Peter Weber]

Gerald,
you being Texan and all, shouldn't that be
'What the heck is he doing out here in that thang?'

------------------
Peter
'99 Sport 4wd SOHC

 

[renz]

I would define the 'roll' as excessive side to side movement when either going straight over a speed bump or one tire first. Of course it is much more pronounced when I go over one tire at a time. I talked to a local shop which said all Explorers feel top heavy like that. There has got to be something that can be done.

Another symptom that I have is when driving highway speeds and making a long turn, if I hit a pothole or bump in the road, it feels as if the truck skips across the road. Does this sound familar to anyone?

Hope this helps.

 

[AgExplorer]

The lateral movement you are referring to is comely known as "body roll". I get the same thing in our 95 Explorer when going into an inclined driveway as one front wheel is ahead of the other. Or when backing out, one rear wheel ahead of the other. I have heard the Edelbrock shocks will eliminate most of this. I am planning on installing a set next month.

------------------
AgExplorer
95 XLT 4X2 4.0L OHV
AMSOIL Synthetic Lubricants & Filters
NGK Platinum Plugs
Jacobs Electronics Wires

 

[NoBoundaries]

I was thinking about this myself and one of the first that came to mind was the placement of the gas tank. I have heard many people talk about the fact that there Explorers sit about an inch lower on the drivers side, I have experienced this myself, and this is evidently the result of the placement of the fuel tank. This could effect how the suspension on one side can react differently then the other due to the fact that one side has more weight on it then the other. Figured I would just chime in with this.

------------------
Tim Y.
1996 Explorer XLT
4.0L OHV 4x4

 

[Peter Weber]

I believe all Explorers have that skip, at least the two I've had. It is directly related to the sophistication of the suspension. We have a number of multi-level freeway intersection in LA. These have sweeping, long curves with breaks were the bridge sections join. My BMW handles these a whole lot better than my Explorer.
By the way, this symptom seems to be even more pronounced on front wheel drive cars.

------------------
Peter
'99 Sport 4wd SOHC

 

[wabbit]

renz,
You note your suspension as being "stock". If this includes the origional shocks, replacement should be the first order of business. Many good choices for shocks are posted here. I have recently installed Monroe Sensi-Trac's on my 91'. I replaces what appeared to be the factory original shocks... at 170,000 mi.!! I noticed a major improvement in overall ride and specifically "body roll".
While you are under there, give your entire suspension system the "hairy eyeball" to look for loose items or components that don't seem properly aligned. Not all suspension wear will be visible but just look...
In a nutshell, try shocks first. And get to know how your suspension components work together.

------------------
'91 Explorer XLT 4WD

 

[Tom Wilk]

The "roll" or lean that I think you might be describing can be controlled with larger anti-sway (or anti-roll) bars. I think that Ford put larger ones on the later Explorers, probably '98 and up to lessen the lean in turns. If you drive primarily on the street, these can help. They do have a negative effect on articulation though, which won't help with rock crawling.

As for the hopping, or skittering across the ground, this problem is inherent in a leaf sprung, solid axle vehicle. It has to do with unsprung weight. The rear axle, along with the wheels and tires, is quite heavy compared to independent suspension. Also, the leaf springs don't do as good a job of locating the axle side to side as control arms do. There is really nothing there to prevent small movements of the axle from one side to the other.

If you've ever looked at other solid axles on cars with coil springs, there are usually either a couple of extra control arms mounted at an angle, or a panhard rod mounted sideways going from the axle at one end to the frame at the other. Both of these setups prevent sideways movement of the axle. With our leaf springs, only the spring bushings and the angled shocks serve to control that sideways movement.

The consequence of all this is that when you hit a bump with only one wheel, the axle bounces upward and sideways. The weight of this whole axle/wheel combination is too much for the shocks to control. Good shocks like the Edelbrocks will help control this. Polyurethane bushings will help as well, since they limit the side to side movement of the spring, but shocks would be my first move.

Tires can make a difference as well. I found that I had a considerable amount of this wheel hop over bumps with the original Firestones, but the BFG's don't seem to do it nearly as much. The stones had some pretty soft sidewalls, which seemed to allow more side to side movement than the Goodriches as well.

------------------
Tom
99 Sport 4x4
SOHC
Auburn Rear & Gerald's old Shackles
265/75-R16 BFG AT's that weren't supposed to fit

 

[GJarrett]

Most of the "skip" you guys are talking about comes from the anti-sway bar.

When you are cornering and one of the front tires hits a bump/gap/etc, that side reacts to it as it should. But, since the antisway bar keeps the two sides connected, your other side joins in the movement even though its tire could have stayed rolling merrily along and planted on the pavement if it had been allowed to truly work independently on its own. And at the same time it's working the other way, too: the tire taking the bump is limited in how well it can move to react to it because it is connected by the sway bar to the tire that is on the smooth part. So you have half your front suspension being held back trying to absorb an impact on one side and the other half bouncing around on smoother ground on the other side while the centrifugal force of two-and-a-half tons of vehicle is cornering (with a few hundred pounds of that unsprung weight on a solid axle that Tom was talking about bringing up the rear) and voila! of course the thing's gonna skip. Face it, we're going to go on a different ride than a lightweight independent front & rear CRV will give.

It's kind of ironic that we have an "Independent Front Suspension" that links together both sides and thusly limits how "independent-ly" it can work.

How do I know this about the antisway bar? Many of you are aware that I permanently removed my antisway bars. As soon as I did that, it immediately started riding much smoother and the first real difference I noticed was that each side of the front really did start working independently. That cornering "skip" completely stopped because while one tire absorbed the bump, the other stayed planted right on the road (of course, now I'm leaning a bit while all this is going on now Dead Link Removed). Now when I hit any bump, gap, railroad track, anything at all -- the suspension soaks it up independently and the difference in the smoothness of the ride compared to the way it was before is astronomical.

Of course, I ain't ever gonna beat any Mustangs going through "S" turns anymore but that's not what I bought this vehicle for in the first place. And of course, without the antisway bar I can really get a lot of that "lateral roll" going if try at it.


------------------
Gerald
"Nerves of Steel; Brain of Chipmunk"
~~~~~~~~~
'99 Eddie Bauer 4x4 4.0L SOHC aka "The Jeepeater"
Mods listed in my Explorer Registry post 7/8/99
Dead Link Removed "What the heck is he doing out here in that thing?"



[This message has been edited by GJarrett (edited 03-30-2000).]