Im just curious. Can they go bad after running bigger tires for a long period of time? Stupid question I had it the back of my head. Or is it just a generally good idea to swap out the stock Tbars for some thinker aftermarket bars?? Thanks

Maxx

I don't know if they "go bad" but they are a spring so they can sag and the steel can become fatigued over time.

Also, as the spring sags, or plastically deforms as we call it, it becomes stiffer. That is often not what we are looking for when wheeling slow crawly stuff.

That said I don't think I've ever heard of a t-bar breaking and many of us are running them in a range of operation much larger than they would normally be.

Frank.

I have seen a broken one. It was not out of a Toyota however. It was out of a Chrysler car - a 59 Plymouth if I recall correctly.

They can fatigue, but it has nothing to do with the tires you run.

If you jump it repeatedly, the excessive shock loads may do it, even more so with a heavy bumper/winch combo up front.

Good thing is they are adjustable, and you can compensate for the fatigue.

I've seen the top a arm mount on the frame side come off. The guy got 4" lift with 3" bodylift and 40" tires. He jumped too many times...twice....hehe.

I'm not too surprised about that. It's amazing that the entire front weight of the truck is supported the threads of three bolts on each side. I can easily see those threads stripping out if you jump the truck constantly, especially with a lot more weight than stock. Still, I'm sure it's extremely rare.

As for torsion bars, don't fall for the BS that people like Downey and NWOR try to sell you that you need thicker torsion bars. Those guys are criminals who pray on the lesser informed to make that extra buck.

Stock torsion bars allow for the most flex. If yours are sagging, or need to be replaced, I would put another stock set in. The ony time thicker bars should be used is if you have a lot of weight up front and/or jump the truck and/or run fast on super bumpy roads like pre-running. In other words, any circumstance where the front end is bottoming out when you don't want it too.

In that case, IMO, the Sway-a-way 25mm are the best compromise between a thick torsion bar and decent flex and they are pretty good quality.

Is there a general rule, scale or measure to compare each additional mm of thickness as far as strength and firmness? I'm eventually getting slightly thicker sway a ways, but I only want enough to handle a 50-75lb simple front bumper.

There is, it's called the polar moment of inertia, I can't remember the exact equation but the diameter's contribution to stiffness is the diameter ^4 power. In other words, a littleincrease in diameter means a big increase in stiffness. I'm reaching back into my memory but I *think* someone actually calculated the difference and found from 24 to 25mm there was a 33% increase in stiffness and from 24 to 26 like a 66 or 90% or increase?

Either way, you wont' be able to get 75lb more load (Take 33% of the weight supported by the front end, that's the increase in weight you'd need to over come the higher spring rate and get back to the flex you have), you'd need say a .2mm increase in diameter.(I'm totally guessing here) However, this is not necessarily bad for if you use the stock bars you will get more flex with that front bumper. Which, unless you are into the fast stuff, is usually desirable.

Should no one pipe up about the added stifness I'll crunch the numbers when I get home.

Frank.