synchro66
Well-Known Member
One end says 449L and underneath 174 The other end says 449L and underneath 2HH which end should be positioned into the LCA
Torsion bar direction
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synchro66
Well-Known Member
Yes..They are a pair 448 and 449 ...but I read somewhere that they could only go in one way, and that was with the L or R stamp facing the front of the car, and what confused me was that both ends have the L or R stamp
Cheers
Cheers
It doesn’t matter which end is forward. If both ends aren’t stamped with the ID number I put that end in the back, so you can see what’s in there later if you forget or someone else gets the car. But as long as the left side bar is on the left side and the right side bar is on the right it’ll be fine.
Only exception to that is the large, zero indexed bars. They’re the ones on that list that only have one ID number - 1.04, 1.09, and 1.14”. They don’t have an offset built into that hexes so they can go on either side, but should be kept on whatever side they were installed on from that point.
4mulas
Fixem'up
Odd number to the driver side and as bluNblu says put the numbers to the back so you know what’s in there
synchro66
Well-Known Member
Thanks guys…. Great info… I can now Install with confidence
MopaR&D
Nerd Member
Sorry if I'm hijacking a bit but I was a dummy and didn't label the 1" Just Suspension bars I took out of my Duster a while back. Is there a way to figure out which side they're supposed to go on? I know if I end up putting them in another car with the sides swapped there's a good chance they'll break...
Depends on which Just Suspension bars they are. Originally they were zero indexed, and had no markings as to which were left and right. It didn't matter until they were installed. The later ones I think were indexed, and those should be marked left and right. If you have the older non-indexed bars, there's no way to tell them apart if you didn't mark them. Unless you can figure out which sides were which based on any witness marks or scratches from headers, steering stuff, etc.
I think the idea that they'll break if mounted on the opposite side they were previously mounted on is overblown. Spring steel doesn't work harden like regular steel, if it did it wouldn't be very useful as a spring! I definitely think best practice is to maintain them on the same side as they've been run on, but unless the bars have sagged significantly (offsetting the hexes) in their previous direction I don't know that I'd stress out about it too much.
MopaR&D
Nerd Member
OK great, that'll help me sleep at night whenever I get another A-body to put them in lol. I don't think they were indexed, I got them in 2010 IIRC and I had them in my car for about 7-8 years so I don't think they had time to sag much. Good point about work hardening too, you're right that shouldn't be the case with proper-grade spring steel although I do think about new leaf springs settling in. I don't recall torsion bars ever doing that though, either the set in question or the 1.14" ones in my Duster now that have been in for the past 4-5 years.
I also have the torsion bars identified as USC 891L and USC 890R on my 71' Demon. I recently rebuilt the front suspension and converted to front disk brakes. I also pondered the front/rear orientation of the torsion bars because, IF the rotation of the bar is important, the way you put the left (or right) bar in will reverse the rotation. I had cleaned up and painted the bars and fortunately I left a witness mark on the left bar that had sassy green overspray on the USC 891L end. I figured that the only way to get overspray on that end is it had to be in the rear position. In summary:
USC 891L marking Left rear by clip
USC 890R marking Right rear by clip
This is all assuming that seeing I just got the car last summer, that no one had messed with these bars in the last 50+ years and they were in there from the factory install.
Swapping the bars front to back doesn't change the direction they twist, it doesn't matter which end points forward. Left to Right matters because of the direction of the hex offset built into the bars.
If you still have the bars out of the car, you can draw a little arrow on them, turn the bar around, and see for yourself. The anchor in the torsion bar crossmember doesn't move, but think about the direction of force required to keep it in place.
Every untouched factory car I have had through my shop had the part # at the cross member sockets. But as 72blu states.... it don't really matter, turn it 180* and it still twists the same!
Although I pretty much only run aftermarket bars in all of my cars I like to put any markings to the rear so you can read them in the anchors. It’s a nice check to have when you’ve had everything apart and back together a few times. So at the end of a long day (or days) you can look and see that you haven’t accidentally screwed something up and swapped the bars side to side.
Just to clarify what I meant by the twist of the bar, I was referring to the relative force on the bar itself. I know that the rotation of the suspension is the same i.e. if the suspension compresses, the lower control arm goes up and it rotates the front end of the bar clockwise. If you switch ends, put the markings in front, the rotation of the lower control arm is still clockwise but relative to the bar, the force is in the opposite direction.
The picture below shows the marked end the bar and the direction of force if the markings are in the Front and what it is if in the Rear. None of this really matters at this point because I am going to install as it came from the factory. Like I said originally, just pondering if it matters. Thanks for the feedback.
USC 891L marking Left rear by clip
USC 890R marking Right rear by clip
The picture below shows the marked end the bar and the direction of force if the markings are in the Front and what it is if in the Rear. None of this really matters at this point because I am going to install as it came from the factory. Like I said originally, just pondering if it matters. Thanks for the feedback.
USC 891L marking Left rear by clip
USC 890R marking Right rear by clip
The force in the bar is the same. Exactly the same. You’ve got the bar marked, now turn it 180°. The arrows will point in the same directions!
Don't care which way you turn it, it twists the same way...
Front to back makes absolutely -0- difference, other than which markings You want to see through the back of the anchor sockets.
Right & Left DO matter, these bars aren't just chunks of billet steel or something, they are formed in a spiral-wrap fashion. R&L are wrapped in opposite directions when formed, besides any clocking, if they're not marked I'd be surprised....or suspicious..
Right & Left DO matter, these bars aren't just chunks of billet steel or something, they are formed in a spiral-wrap fashion. R&L are wrapped in opposite directions when formed, besides any clocking, if they're not marked I'd be surprised....or suspicious..
Hmmm. The MP bars that didn’t have a hex offset (zero index) had a single part number, no left and right because the hexes were flat to flat. The old PST 1.03’s were the same, zero index and no L/R.
Some of the bars do have kind of a spiral pattern to them, but my understanding is that’s a “finish” because they’re ground to the correct diameter after forging. I talked to a Firm Feel about custom bars once and they said they’d have to be ground down from their next size up, hence the cost.
I know @autoxcuda has been running 1.14” MP bars that have the same part number on both sides for a very long time now. Anecdotal of course but if there was an issue I’m sure he’d have run into it by now.
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