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-   -   Rear trac bar (https://www.irv2.com/forums/f87/rear-trac-bar-501840.html)

Tacouser 08-12-2020 07:32 PM

Rear trac bar
 
We have a Class C 32. It came from the factory with a rear sway bar. But I have read about adding a rear trac bar. What is the trac bar designed to do? Does it take the place of the sway bar? Does it hang down low past the axels? Is it worth the money?

twinboat 08-12-2020 09:01 PM

Before you install a track bar, if you have the stock anti sway bar, a new heavy duty one may help a lot with sway.

A track bar sits above the axle and claims to stop the rear springs from bending sideways. If you look at the springs, they are hardly going to bend that way.

With the track bar mounted up over the roll center of the axle, the way they design them, causes it to work more like is an anti sway bar then a track bar.

I had a 2000, 30 ft, class C. It was a horror to drive with big rigs passing. Once I upgraded the rear anti sway bar, it became a pleasure to drive.

Earl II 08-12-2020 09:14 PM

Quote:

Originally Posted by Tacouser (Post 5394198)
We have a Class C 32. It came from the factory with a rear sway bar. But I have read about adding a rear trac bar. What is the trac bar designed to do? Does it take the place of the sway bar? Does it hang down low past the axels? Is it worth the money?

The Trac Bar is supposed to deal with "wag the dog" problems where the back end swings back and forth from trucks, wind, etc. This can cause you to have to make severe corrections in steering which can be very, very scary. Sway bars deal with the top end "tipping" back and forth. In our case, with a 32' Class A, the Trac Bar was well worth the money.

sibe 08-13-2020 04:41 AM

The track bar is for ffine tuning a rear leaf suspension...

some complain of a shutter on the rear etc or a wag in rear.. yes this occurs on certain RV's do to many factors.. I would bore to sleep the senarios..

The rear track bar on a leaf suspension comes in 2 designs.. again complex, , the simple is a long bar from one side of frame to the Rear axle on the opposite side to stop side to side shake..

Tire design, capacity and airing up account for a large portion os issues..

Next is the Sway bar.. there are HD bars, leverage fixes, mods and better bushings and links that help drastically.. for the rear.. along with good shock

Same for the front,, ,, no track bar unless it is a 4x4 coil conversion C.. LOL

Do not just look at mods or changes to one end,, sure it helps but can then show the ugly in another direction,, balance frt / rear.. 4 shocks, all bushing and rod ends etc..

One thing I have been seeing on some new pick ups is Sway bars that are ACTIVE..

The bars have a servo type motor that loads and unloads pressure on a lever system like a torsion bar.. Normal setting, a firmer for towing and soft for off road rock climbing.. what ws nice too is the link ends had no RUBBER bushing/sleeve mounts, they are all hiem/ball joing style,,, no flex or slop..

On an RV sway bar you get an 1/8" deflection in each rubber mount bushig and another 1/16" on each end link... that can be 3/8+ each way on bar, then do a vector from the frame to top of RV, you will see a few inches of free roll. not controled by sway bar..

Just being critical...and me......

George Schweikle 08-13-2020 09:02 AM

The universally accepted basic functions of these suspension modifications are:

ANTI SWAY BAR: reduces LEAN

TRACK BAR (Panhard bar): reduces side-to-side SWAY by eliminating any looseness in the leaf spring suspension of a solid axle.

Sometimes it's tempting to open one's wallet and throw a lot of money and parts at a problem. Before doing this, it's better to define the problem and then understand what a suspension modification actually does. This can get complicated since some products can have a large primary affect and sometimes a lesser secondary affect and sometimes lean and sway are combined. There are other things that affect handling like wheel alignment & tire pressure, Sumo Springs, and different shock absorbers but the basics of lean and sway reduction are as stated above and are known to work.

Sway bars and track bars can both be applied and are both worth the money if your problem is solved.

Quote:

Originally Posted by Tacouser (Post 5394198)
We have a Class C 32’. It came from the factory with a rear sway bar. But I have read about adding a rear trac bar. What is the trac bar designed to do? Does it take the place of the sway bar? Does it hang down low past the axels? Is it worth the money?


sibe 08-14-2020 04:36 AM

went back to my roots.. called an old timer.. built asphalt and dirt race chassis since father time.. 6
late late 60's early 70's .
I did remember back in 70's at our local track that I was drawn to every staturday to hope to turn wrench or get to turn the wheel some day....
Adding a Track bar was not allowed for the longest time... so I had my thoughts from all this RV stuff and called him..

After 2/1/2 hours of catch with Mr tobias heir.. he explained the track bar, long style from opposite frame to rear axle. from frame to center axle above.. and center with pivot to both sides of frame.. then also when you move one end off axle center line ..(when racing left handers) , Then into adding lateral bars.. .. then into coils suspensions , 5 links.. MY BRAIN is still sorting.. It was past 11pm and he said he was missing the news and had to go.. LOL Nice talking son....blah blah...

SO the trackbar done on same center line of axle in a limited travel suspension like RV or rig can help the shake, it will do little to nothing to real roll or tipping.. You RV saw wag, he calls it shake or shutter,,, it is what would break traction sliding the rear on the dirt strack or break it on asphalt into a spin.. on the old leaf spring cars,, the track bar locked the axle into a steady plane..
In a heay truck more like a rig.. the rear springs of the time had sliders and an open end.. this would cause the axles to slide around,, upper track bars kept the centered and stopped the pivot shake sometimes the trailer would induce..

He mentioned the tall spring packs used on 80-90's RV,, they would leverage some shift and give the shake.. He said newer trucks like his has longer leafs for ride that are less leafs but thicker, wider.. They actually twist and rool more than those old thick stiff packs... He talked about sways bars, a little but got carried away with coil and link system..

As the last many have said if this stuff.. track bar, hd sway, konis.. hd tires... putting mother inlaw in the back... whatever.. helps then money well spent.. still alot of factors why..

GABob 08-14-2020 06:05 PM

Went to the Safe-T-Plus factory west of Atlanta to have their front stabilizer installed. Saved quite a bit having them do it over a dealer, and when I was there the one gent told me about the track bar to address the "wagging the dog" issue you sometimes experience when changing lanes. I saved enough on the first install that I could afford to swing that option as well, and as I travel with precious cargo I have no issue with spending for safety if it makes sense. Had it done, and tested the unit. Steering feels tighter and lane changes seemed to be much better as well. I think it was money well spent.

Ron Dittmer 08-15-2020 07:32 AM

On our 2007 Ford E350 chassis motor home SEEN HERE, when new in 2007, I had the rig outfitted with front and rear heavy duty Roadmaster stabilizer/sway bars, a rear Henderson trac bar, a Safe-T-Plus steering stabilizer, and today with heavy duty Bilstein RV shock absorbers.

Our previous motor home handled very poorly the first 12 years until we modified it up the ying-yang for it's later 12 years, so I wasn't going to mess around with our new purchase in 2007 that we planned to own for the rest of our driving years.

I can say that I believe the rear trac bar would be the last feature to add. If on a tight budget, I would make the following upgrades in this priority.
1) heavy duty RV Bilstein shock absorbers
2) heavy duty steering stabilizer (there are a few good brands out there)
3) heavy duty front and rear stabilizer bars (either Helwig or Roadmaster)
4) rear trac bar

If your rig is a 2007 or older E350, Ford did not include a rear stabilizer bar, so if your rig is that kind, a heavy duty rear stabilizer bar becomes #1, and the front stabilizer bar becomes #2.

On the E350 and E450 made 2007 and older, the front stabilizer bar is nearly ineffective so I would "up" it's priority as well. The end links wear quickly and the bar itself is very thin. It is the same front stabilizer bar Ford put on the E150 van.


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