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Frank Ball's Pre-'97 Dakota Rear Anti-Sway Bar FAQ

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Dodge puts a good anti-sway bar on the front of most Dakotas (it depends on what options you get), but there is no rear anti-sway bar available from Dodge.

There are three manufacturers for front and rear anti-sway bars for the Dakota: Hellwig (SportTech), Addco, and Suspension Techniques.

The stiffness of the anti-sway bar depends on two things: the diameter of the bar (bigger is stiffer) and the length of the arms going from the pivot points to the axle (shorter is stiffer). I don't have data for the length of the arms on the different sway bars, but I think they are close enought that the difference in diameters dominates in determining the overall stiffness.

The stiffness of the bar is proportional to the diameter of the bar raised to the 4th power, so a small increase in diameter yields a large increase in stiffness. The Hellwig bar is 3/4", the Addco bar is 7/8", and the Suspension Techniques bar is 15/16". If we use the Hellwig bar as a starting point we can calculate that the Addco bar is 85% stiffer and the Suspension Techniques bar is 144% stiffer (32% stiffer than the Addco bar).

How stiff is good? Is more better? Anti-sway bars do several things. They reduce body roll in turns. This is good, so more is better if this is all we consider. The ratio of the stiffness of the front bar to the stiffness of the rear bar will have a huge effect on understeer or oversteer. As the stiffness of the rear sway bar is increased understeer will decrease, eventually leading to oversteer. So don't go sticking a massive rear anti-sway bar on a Dakota with no front anti-sway bar (or a small diameter front anti-sway bar), the result could be dangerous handling (Oversteer is tricky, if you don't correct for it you spin out. Understeer is safer, you just run wide in a turn and you can easily turn in tighter to compensate. Almost all new vehicles are designed to understeer).

The last effect of anti-sway bars concerns only offroad driving. They reduce the ability of the suspension to track over very rough terrain, which can cause the truck to get stuck because a drive wheel gets airborn. Imagine terrain where the left front and right rear suspension is compressed. The opposite two wheels will need to extend fully to reach the ground. The anti-sway bars resist this kind of twisting force and can keep a wheel from reaching the ground. Serious 4WD owners often have sway bar disconnects or just don't use them at all.

On my '95 SLT club cab the front bar is 1 3/32" diameter. Stock the handling understeered very hard. With the Addco rear anti-sway bar added it still understeers, but not near as much (and it will oversteer under certain conditions like bumpy turns or hard acceleration).

Most Dakota front anti-sway bars are 1 1/8" and come with rubber bushings. Urethane bushing kits are available. Urethane is stiffer and lasts longer, but squeaks.

The Shelby Dakotas came with both front and rear anti-sway bars, but they are both rather small in diameter.


Here are some testimonials from the mailing list:

From: DFuller288@aol.com
Date: Thu, 4 Jan 1996 21:06:24 -0500
Subject: Dakota Anti-Sway Bar

Just installed a Hellwig SportTech rear anti sway bar on 93' 4x4 club cab with 5.2L. Unit fit perfectly out of box. Simple bolt on operation took less than 1 hour. Bar makes a noticeable difference in reduced roll in hard cornering. Got unit from Summit Racing Equip. for about $100 including shipping. Well worth the money for in handling improvement.


I installed a Addco rear anti-sway bar shortly after buying my truck. It is 7/8" diameter. It goes across the frame in front of the spare, with a dogleg to clear the spare tire, and the arms attach to the lower shock mounts. It required drilling four 1/2" holes in the frame. Polyurethane bushings. About $180. Body roll is greatly reduced, and so is understeer. Highly recommended. The truck still understeers on a smooth road, but it is tolerable. Of course the back end will bounce out when it hits a bump. I'm wondering if better rear shocks would help, but I'm know that the solid rear axle suspension has its limitations. There is no loss of ground clearance with the Addco bar. I think that the Hellwig bar mounts under the rear axle with the arms going back to attach to the frame (the opposite of the Addco bar), and so the Hellwig bar might reduce ground clearance under the rear axle.

Frank Ball
frankb@sr.hp.com       (707) 794-4168 work 
Rohnert Park CA         '95 Dakota SLT Club Cab V8 5-Speed 2WD


Date: Mon, 8 Jan 1996 21:21:42 -0500
From: MagnumMrk@aol.com
Subject: Re: rear sway bars

Hey!

I did some calling today and found Suspension Techniques has a 1 1/8" front and a 15/16" rear sway bar kit for sale.The cheapest place I found to buy it is A.S.A.P.The 2 bars come complete with urethane bushings for $229.00.If you don't already have a front sway bar they will sell you an installation kit.


Mark


Corrections and additions are welcome.

Frank Ball   1UR-M          frankb@sr.hp.com        (707) 794-4168 work 
Hewlett Packard             (707) 794-3038 fax      (707) 538-3693 home
1212 Valley House Drive      Kawi KDX200, Yamaha XT350 YZF600R Seca 750
Rohnert Park CA 94928-4999     '95 Dakota SLT Club Cab V8 5-Speed 2WD

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