So, y'all have MEASURED the 318 bars and they're the same as the 440/police/HD bars? I'm inclined to think that's a misprint, but I guess stranger things have happened.
Scott, are you looking for the elusive '74-only 44"x1.06" bars? They don't exist... Dodges and plymouths went to 47" in 74, AFAIK. I'm a c-newbie, though, so...
Clair, my 318 vert had .94 bars and the 318 4dr had .98 (actually the mic read 1").
That is the first time I have ever heard anyone dispute the switch over year on 47" bars. Which means, we need a 74 owner to step up! Don't want incorrect data in the tech section!
Joined: Sat Dec 10 2005, 04:28PM
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Going with Bills part numbers, I concur. My part numbers are the same.
I took it a step forward and dug out the Hollanders. It says: "In progressive higher Capacity"
ID Number 574 (R) 575 (L) 576 (R) 577 (L) 578 (R) 579 (L) What fits what, it doesn't say. Logic, to me it would be sized by weight. But going by the parts books, my impression is not so. These numbers are located on the end of the Hex on the forward end of the shaft. In my case, for the 72 Polara, that's a 72 & 73 Polara and monaco, 65 to 69 Fury & VIP and 70 to 73 Fury.
It Gets better and may resolve some of our interest in beefing up our front ends. I went to the next number, Hollander Ref# 19 (71 Polara) 618/619 65 to 71 Dodge ONLY 620/621 (65 to 73) What ever that means 622/623 (Full Size) 962/963 74 to early 76 964/965 Late 76 to 78 It doesn't say what the changes are Applications: 65 to 78 Chrysler, 65 Custom 880, 65 to 71 Polara/Monaco, 74 to 76 Monaco, 77 Royal Monaco, 74 to 75 Imperial, 74 Fury and 75 to 77 Gran Fury.
A 65 Newport weighed 4025 Pounds, and a 78 newport weighed 4394 Pounds. The Dodge, 65 to 71 Polara weighed 3905 (65) and the 71 weighed 3820. My 72 weighs 3975. It looks like the pre 71 the choices are very large, and the 72 up the options slim down. But I have to say the Reference #19 is where we should be looking, particularly 65 to 78 Chrysler.
Now I'm confused because the Polara, a 200 pound heavier car than the mate Fury, had the 577/578 set in it, but a 71 Fury 3 with a 318, had the 574/575's in it. I suppose what I really want are are the 44 inchers, 578/579. I know the 71 Fury and the 72 Dodge share the same sub frame and front end parts. So what's the deal here?
BTW Scott, I agree with your measurement, but you need to allow for the paint. That 2 10ths your talking about are probably the paint.
Now I have a new question. For years it has always been drilled into me a scratch in a T Bar is real bad. What about surface rust?
Does anyone make replacement bars for these beasts?
<span class='smallblacktext'>[ Edited Sun Apr 09 2006, 09:40PM ]</span>
Joined: Tue Oct 11 2005, 01:33AM
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Surface rust being a uniform condition shouldn't produce a localized stress point like a scratch or gouge would. I think you can compare to a sheet of glass, sanding the surface doesn't seem to weaken it, but it will always break on a scratch line.
Joined: Sun Feb 05 2006, 11:51PM
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A deep scratch (like those made with gripping tools) could set up a stress riser that leads to cracking. The proper tool to remove T-bars is a V block clamp with smooth jaws that has a surface to hammer on. Light surface rust shouldn't be a problem, as long as it's left alone. Grinding it out would weaken the torsion bars. I treat T-bars like a spring under a lot of tension - no digs, deep rust pitting, grinding, bending, and no stretching in the opposite direction to what it was designed for (swapping them side for side is out) and they will perform the way Mopar intended. BTW, if you want to see if the bars are twisting the same amount under load jack up the front of the car, set it on jackstands to load the suspension, and paint a straight 1/8" white stripe down both bars. Then jack it up and set the stands under the framerails to let the suspension hang. Look at the stripes and you can measure how far from straight the lines become.
For cleaning rust I had my bars hot tanked then shot peened. The shot cleaned them up nice and is supposed to give them more surface tension and make them stiffer, in theory.
Joined: Sat Dec 10 2005, 04:28PM
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Yeah OK Thanks. Some of it is pretty rough, but I know where there is another set I can get.
Now it's a matter of which T bar I should use.
BILL! I have a set of 574's (.94) that came from a 71 318 Fury, and the Polara came with the 577's (.96). The 574's are the ones used on the 318 Cars. I don't get it. Could they have tensioned the .94's more than the .96's? Either way, which would you use? I am leaning to the 574
<span class='smallblacktext'>[ Edited Sun Apr 09 2006, 09:26PM ]</span>
Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
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I think I'd go with the 574-5 bars. The spring attribute of a T-bar is really a combination of three factors, length, diameter and the tensile strength of the steel used. I think we have been mistakenly assuming the bars are all made with the same steel and that the diameter is the key figure. Of the three bars used in 70 Plymouths, the 578-9 (0.98") bar has the most spring rate. Logic says the bar used in wagons and 383 has to be tougher than what a 6 cyl would use. Hence the steel used in the 574-5 (0.94) bar is harder than the steel used for the 576-7 (0.96") bar.
So the answer to your question "Could they have tensioned the .94's more than the .96's?" is no, but they did use better steel.
What I'd really do is try to find a set of 578-9 (0.98") bars, which should be easy to find since all '70 318 cars had them. If you can find a police, taxi, wagon or 440 car you also get a front sway bar as well.
Joined: Sat Dec 10 2005, 04:28PM
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See that? I was thinking the same thing you were, but not getting to geeky about it. (I have to think I'm dealing with idiots all the time with my job. Sorry)
I happen to know where there is a set of 70 T Bars too. I'll check that out. THANKS!