sway bar or track bar, what's the difference?

[The_Handier_Man1]

From: salplmb (Original Message)
Sent: 5/15/2003 9:25 PM

i was just wondering if anyone knew about the difference between the two. my 73 d22 440-3 indian has a sway bar in front but nothing in back. dose the sway bar in front work the same as a track bar? would it be more benifical to install sway in back or track bar? i assume that both should be the same. so putting sway on back would easier and cheaper but really want the best set up. thanks for the info and help.
sal

 

From: denison
Sent: 5/16/2003 7:09 AM

Unless you have a problem with the coach swaying, why would you need to add a sway bar in back? My 72 D22 doesn't have one at all. 

 

From: salplmb
Sent: 5/18/2003 10:10 AM

i do notice a sway in the back and was just wondering about it. my 73 d22 came with a sway bar up front but not in back. i thought this was odd because i have seen them mostly on the back. just wasn't clear about the difference. im probably just parinoid baout handeling.thanks
sal

 

From: denison
Sent: 5/18/2003 11:28 AM

My 72 handles as well as I expect - though nothing like the Jaguar I used to have - and has no sway bars front or rear, nor lateral locating bars like my cars with coil springs in the back. If I wanted to locate anything with freedom of motion where there should not be, I would have an assistant, a good sized adult preferrably, start pushing sideways on a rear corner of the coach, a good shove each second or so. This would get the coach yawing as much as its suspension would allow - the amount might surprise you. I would lie underneath and look for relative motion. Chock the wheels of course. Loose or broken spring shackles, cracked springs, loose spring u-bolts, just to see where the movement is happening. Then if the assistant pushed sideways in the middle of a wall, as high as they could reach, you could watch for things that were allowing sway. This might require a couple of assistants. One of the things I am looking forward to at the june jamboree in Pa is the chance to drive each others rigs a little and see how they handle. Mine might actually be horrible compared with another! denison

 

From: spudboy
Sent: 10/13/2006 9:16 AM

I have ordered front and rear sway bars for my 72 D22 Indian.  I ordered them from Summitracing.com.  They are made by Addco and are supposed to be direct bolt-ons for the M350 chassis.  They go for about $150 each.  I am trying this instead of air bags since my buddy, the truck suspension and alignment guy, doesn't think much of air bags (although most of fellow CWM do).  I am going to replace (add, since they are not even present) the front spring bushings and re-arch the front springs as well.

I drive the Spudmobile in the mountains quite a bit, and have never been real comfortable with the way it handles on twisting roads.  Part of that is probably the 17.5 inch bias ply mud and snow tires, and part of it is a big box on a delivery truck frame, but even after new shocks and a steering stabilizer, it is hard work to drive.

More when all the parts are bolted in place.

 

From: Phåråoh
Sent: 10/13/2006 5:14 PM

Considering that RVs, buses, and semis... all the heavy road vehicles you can name, have been using them for years (not just the preference of CW users), if sway bars were the best way to cure body sway and improve diriveability on large vehicles, then it only makes sense that anti-sway bars would be all they'd have, wouldn't it?   The bars are cheaper, to be certain, and do help, but there's no substitute for the air bags... and, sway bars aren't adjustible, so you can't tune them to the type of roads you are planning to drive at any given time.  Nor can you add a small compressor, gauges, and valves and make them remotely ajustible, creating a campground leveling system or instantly adjustible to changing road conditions.

Many cars have front and rear sway bars, my PT cruiser has both, but what truly reduced the body roll and improved driveabiltiy was adding progressive rate coil springs.  On an RV, they'd be a coil spring added to leaf springs or... airbags.

Here's my opinion from using them for 2 years now... absolutely, totally worth every penny!  Not only do they reduce the body sway, they improve the ride and can be tuned to varied road conditions.

Surely, get the sway bars, but if you do a lot mountain driving with sharp turns and really want to make a significant improvement in your rigs driveability, get the airbags too.  They certainly won't cost any more than spring re-arching and are a whole lot less hassle!

- Sob

 

From: Elandan2
Sent: 10/13/2006 6:41 PM

I put air bags on my rig and the difference is unbelievable.  My rig has factory sway bars front and rear but the improvement to both body roll and ride with the air bags was incredible.  I also drive in the mountains and have always looked for ways to improve the handling of our motorhome and I think that the air bags were the best money spent on a suspension improvement by far.  Rick

 

From: Cooneytoones
Sent: 10/14/2006 9:32 PM

Sway bars and air bags do different things on a vehicle...

Sway bars work horizontally with the ground and are to keep the chassis (rear) stable, and relieve pressure placed on the wheel bearings... just as a front stablizer bar does with the front suspension...It also relives pressure on the  front wheel bearings and the king pins..so that the chassis does not sway....a totally differnt principle than air bags, sway bars and front stablizer bars will help your steering some.

Air bags (work vertically) keeping the body from rolling or comming down on the frame, they are a support system for the springs and shocks, they also help keep the wheels pushed toward the ground thus giving you better traction  (more friction)....the more tire that touches the ground and does not bounce off the ground the better your ride and handling will be.

Together, both items work in harmony, giving you a much better ride and handlng ...... if I had to choose one over the other...the air bags would be my choice...........no questions asked!  Adding both would be a great benifit to you....Just adding the bars, I doubt you will notice a difference, especially when a big rig blows by you and the aero-push, tries to move you out of your lane.... Air bags help this problem, but will never eliminate it totally, due to the fact, the air that the big rig is moving.... has to go somewhere....and when it hits that big flat Winnebago.........Well we all know what happens then.....air bags greatly reduce the problem....sway  bars will do nothing except help you steer back into the lane you was already in.

Timmy

 

From: Phåråoh
Sent: 10/15/2006 5:38 AM

Thanks for the excellent explanation, Timmy!

Also, the question included trac (traction) bars.  I haven't seen these since the 70's on street rods.  They were simply weighted bars attached to the rear axle designed to add weight so the wheels wouldn't travel as high over bumps, getting them back on the pavement faster.

- Sob

 

From: brakeparts
Sent: 10/15/2006 8:18 AM

Spudboy -

Do not be surprised if these do not fit. You have an M400 drum chassis, based on what I remember. These are different than any disc brake truck. Further...

I went to the ADDCO website to review their cataloging and it is at best poorly written specifications. It states that it fits the 300 and 500RM series chassis to 1979, but there is a problem as the 300 and 500 are totally different chassis. So what are they saying? BTW, what is a 500RM chassis (typo? misstep?) And what about the very popular M400 disc brake chassis?

Frankly, I'm of the opinion that the add on air systems may offer the easiest means of adding stability and capacity as well. I have very little experience here, but I sold a system once for regular one ton p-ups and it does seem to do the job. Plus I think these offer more flexibilty in installation.

Good luck with the experiment!

Regards,

Geoff
Alretta Truck Parts Inc.

 

From: Cooneytoones
Sent: 10/15/2006 10:43 AM

Yes, the trac bar now is the third principle in the equasion.

It works not only in adding weight, but balancing the sway bar with the chassis keeping the rear end and frame from twisting upon torque, keeping the wheels embedded more evenly toward the pavement in a straight line.
This is somewhat of an antiquated way of doing it. That's why they disappeared after the mid '70's.

Today it is done with X  bars that cross the frame near the center....( rear to opposite side front ) and an adjusting bolts to push down or pull up on the suspension tracing all four cornors of the frame instead of just stabilizing the rear end.

Trac bars are still used by some NHRA drag racers (especially on vintage hot rod vehicles) due to the tremendous force on the rear end and chassis tring to twist upon initial start and shifting gears with near full torque appiled.

Trac Bars do very little to help handling in right and left turning...but help keeping the rear wheels in a straingt line, and lift the rear of the body and chassis off the ground upon the application of torque. They also help stop sideways pull on the drive shaft, sideway pull will damage not only your tires, drive shaft, and u-joints, but is murder on you entire drive train. Along with those they little ditties trac bars also help stop the bouncing and twisting of the tires off the pavement, and jack up the rear for that cool race car appearance.

The weight of our rigs give us plently of traction, unless
anybody out there is doing a lot of burn out's with your rig, thenthey will help... and if they have them that will fit a truck application, adding them, In my opinion, you wouldn't even know they were there except by looking at the receipt for their cost.

Timmy

 

From: spudboy
Sent: 10/23/2006 9:13 AM

A month later and still no sway bars.  Probably will add the air bags too, as that was my original though three years ago.  Now I just have to win the lottery.  Results: next year?

-Spudboy

   

From: tatkin
Sent: 10/23/2006 6:45 PM

I don't say much , but .  I wish and I may well add the ? pump that keeps pressure to the air bags , at will.   

In the city , Milwaukee / Wisconsin area , the roads suck at low speeds, the air bags like 30 lbs. 

On the xway though the bags really like 60+ lbs ...

It would be nice to be able to do this alteration without having to pull the pump out and get
in front/back of the rig and fill them airbags for these occurences ...

 

From: bluebird5750
Sent: 10/24/2006 8:13 PM

Since all of these rigs have a leaf  spring set up, a track bar will do nothing. The track bars only job is to keep the rear end housing centered. Race cars using ladder bar or a 4 link set up has to have the track bar to keep the rearend centered under the car. They run from the frame on one side to the rearend on the opisite side.  Sway bars are what you want. I don't know if summit racing would have what you want or need, as they are very large on motorhome chassis. The one on my gm 30 is about 1 3/4" in diameter. I could measure it if someone needed the exact diameter. I dought if one from a pickup would do much good. My son-in-law has a 1 ton duelly. His sway bars are much smaller than mine.

   

From: Coachmen1972
Sent: 11/19/2006 6:56 AM

Call me weird, but I like the ride the way it is......that "motorcoach" feel....lol.