[mopar56]

my sons 89 Daytona has a round tube that runs down the middle of the rear axle (the rear axle is a "c" chanelle ) the round tube broke at one end where it is welded to the end of the axle flange, I welded it which held for a while then it broke several times again in the same spot over the years, once again the weld has let go, when it dose the pipe rattles, as it dosnt really seem to do anything I am considering just removing it all together, anyone run int this before?, it seems the proper fix is a whole new auto wrecker axle, but a lot of work if not necessary?

 

[KOG]

That's a "sway" (antiroll) bar built into the axle. Replace axle, the bar is spring steel and cannot be welded at home.

 

[Bob Lincoln]

I'm facing this issue right now with the replacement axle that I got when my spring perch rotted and let go. As a temporary measure, I loaded it up with Liquid Nails about 1 foot in from each spindle to hold the bar from rattling; it's still drying now. I plan to have the ends welded at a body shop as a permanent fix. Do NOT remove the bar, the axle needs it to help maintain rigidity and to aid in suspension control, as KOG said.

 

[mopar56]

ok I get that, the reason I thought I would remove it is it litterly has not been doing anything for 3 years now as you mentioned it is difficult to weld so at best it has had a tack to stop the rattle but as far as actually doing anything purposfull it has not, now there is another bar that runs behind the axle that I thought was maybe a sway bar about 1 1/2 inchs in diameter that is intact and gives support

 

[Bob Lincoln]

That's called the track bar and helps stabilize vertical motion as well as rotation in the horizontal plane. The hollow tube inside the U-channel axle acts like a torsion bar, to prevent and restrain twist and bending of the U-channel.

And it is LOUD when it breaks loose. For a day after I replaced the axle, it was fine, then got louder and louder. I think both ends of mine are free-floating. I didn't fill with Liquid Nails at the ends because I want to keep the option of tack-welding it. But I needed to stop the noise. So I filled the U-channel about a foot in from the ends and used duct tape wrapped around the bottom to hold it in place while it dries. Tonight or tomorrow I'll lower the car and test-drive it - I put the stuff in on Sunday. If tack welds don't hold, then I'll fill the U-channel at the ends to keep the bar from rattling.

 

[swynja]

I had the same problem on my former car, a 1992 Plymouth Acclaim. That rear bar broke loose at about 80k. I eventually "fixed" it by putting an exhaust clamp over the axle, wedging a piece of hardwood under the round bar to keep the axle from making noise. Had to retighten exhaust clamp ocassionally, but it stopped the noise. Continued to drive the car to 220k with no further issues although I always wondered how safe it was...

 

[mopar56]

well the only issues I see with you fixes are although the fixed the rattle I cant see how either one adds or maintains any structural support, without the ends being securely welded to the u-channel it cant possibly help with roll which is why I thought I would remove it all together, on mine there was actually a 4 inch piece of material that broke loos from the end and was removed and had a small replacement piece welded in its place about two years ago but again it continually breaks loose, I think I am flogging a dead horse here unless I replace the rear axle with a good used one, a big job for a grocery getter car that rarely leaves town

 

[Bob Lincoln]

Good luck finding a good used one. Mine came from PA to MA. There was nothing left in New England.

It still functions with either tack welding or gluing, because without it, the U-channel is free to flex or twist. With the bar in place, the axle flanges cannot twist in relation to each other; without the bar, there is only the U-channel and it can twist as the flanges rotate in opposite directions from potholes and bumps. Even if the bar is free-floating in the flanges and rattles, it restricts how much the U-channel can twist, just by virtue of it being inside the U-channel. Once it's removed, the U-channel can flex or twist more than the bar would allow. Then you have permanent distortion, wheel misalignment, and a host of problems.

 

[valiant67]

And there's no guarantee that a nice, clean, rust-free southern axle won't have the exact same problem with broken welds.

 

[mopar56]

yeah it definatly wasnt a rust issue here. there is very little rust here where we live,(except on the Japenese cars of course), this car has no rust what so ever I think its just a design thing well maybe I will tack weld it again, part of the problem here is that our driveway which is very long and gravel has many pot holes untill you get to the house so that is why it keeps brakeing.

 

[B10alia]

There are a couple of other options you can explore if you can't get the bar back together. Some folks have added a bit of stiffness by carefully welding a piece of flat stock to the U channel's open end, essentially making it a box section. Addco and PolyBushings sell add-on sway bars that are designed for these cars. I think you'll find that the handling is much worse with the bar broken, even if you secure it so that it isn't rattling. But either way, keep it in there. The U-channel, at least on my '95 Spirit, isn't really all that substantial.

 

[mopar56]

well yesterday I welded the tube inside the u-channel again keeping in mind weld can only be applied to the bottom of the tube but it is stiff again for awhile, I do like the boxing in idea though, that would be fairly simple how far in from the outside of the u-channel would you go?, 6 inches maybe?. I f I did this would I require that aftermarket sway bar kit as well do you think?

 

[Bob Lincoln]

There is another way to weld more of it, but you and I both are unlikely to do this, unless forced to: if you remove the entire wheel assembly, spindle with backing plate and all, and fluid line, you can weld the entire circumference of the bar in the hole, from the outboard side. It's the only way to gain access to it, and it may be how the factory did it. But it's so much work I'd only do it as a last resort. It would disturb the rear wheel alignment, requires bleeding the brakes, and would take hours on each side.

 

[KOG]

As Bob noted, don't try this at home. Again, you're dealing with spring steel which does not appreciate being heating to welding temperature and which will break again afterward unless properly heat treated. And you can't do that.

 

[Bob Lincoln]

So, perhaps this won't work for a pro to weld this for me? He was going to tack-weld both ends.

 

[B10alia]

Here's where the boxing-in idea came from: http://www.allpar.com/eek/swaybars.html.
That page says that the Addco sway bars are rubbish. I don't know how accurate this information is on any of those pages. Many of them are very old, and those who wrote them aren't around here anymore. If you decide to follow that advice, the PolyBushings sway bar is a different design anyways.

 

[KOG]

I've used ADDCO bars on several vehicles with excellent results. They are not going to have the instant effect of a bar welded into the axle due to the compression of bushings, but they're certainly as good as any OEM bar which uses bushings.

 

[mopar56]

Bob I get your idea but in my case not only did the bar crack at the outside but it broke about six inches in to and was missing so I replaced it with a piece of hollow round stock, not spring steel so not only could I not use this method because I couldnt reach in deep enough with the wire feed but I am not sure the tube is really doing all that much any way, I think boxing the "u" channel is going to be my best bet then maybe I will look at the addition of the sway bar

 

[KOG]

Boxing the U channel is an absolute no no. That will increase its torsion rigidity waaaay beyond stock and it won't be able to twist at all. You'll have an oversteering monster on your hands.

 

[mopar56]

hmmn...well I guess I will either have to find a good used axle or get rid of the car, anybody know what years or models the axles interchange from?