bdjr Posted August 8, 2006 Share Posted August 8, 2006 hey guys going to soa my truck but the perches got me thinking need some help. do you fab your own? if so got any pics? can the perches at the local auto parts store work or is ther a donor application at the local yard i could use? thanks bill :hmm: :dunce: Link to comment Share on other sites More sharing options...
Bounty Hunter Posted August 8, 2006 Share Posted August 8, 2006 New ones run about $20 a pair at any 4wd shop or maybe the stealership. Link to comment Share on other sites More sharing options...
87manche Posted August 8, 2006 Share Posted August 8, 2006 mopar performance perches. Available at your local dealership. $8 a PAIR. They're beefy, meant for the musclecar group, larger than the stock d35 perches. PN DCC-4120074 Link to comment Share on other sites More sharing options...
pingpong Posted August 8, 2006 Share Posted August 8, 2006 I build my own out of 2x3x1/4 walll tubing. Makes for a nice beefy setup, and you can make them as long as you want, and of set the center pin if you desire Link to comment Share on other sites More sharing options...
Bounty Hunter Posted August 8, 2006 Share Posted August 8, 2006 I've seen were longer spring perches induce spring wrap, more leverage on a thinner part of the spring pack. Can't beat that stealership deal, I couldn't make 'em for that much. Link to comment Share on other sites More sharing options...
pingpong Posted August 8, 2006 Share Posted August 8, 2006 I've seen were longer spring perches induce spring wrap, more leverage on a thinner part of the spring pack. Can't beat that stealership deal, I couldn't make 'em for that much. Un less you had some 2x3x1/4 wall tubing left over from building rock rails :D Link to comment Share on other sites More sharing options...
bdjr Posted August 8, 2006 Author Share Posted August 8, 2006 yeah you can't beat that price. called local mopar yard and ordered them will get them wed. thay are heavy duty per the service guy, used for their new muscle car springs. they still need to be weldedon thou but i can handle that bill Link to comment Share on other sites More sharing options...
feerocknok Posted August 9, 2006 Share Posted August 9, 2006 I've seen where longer spring perches induce spring wrap, more leverage on a thinner part of the spring pack. I always though the opposite. In extreme opposite, setting it on a pencil set sideways seems like it'd wrap horribly. Link to comment Share on other sites More sharing options...
jage Posted August 9, 2006 Share Posted August 9, 2006 I've seen where longer spring perches induce spring wrap, more leverage on a thinner part of the spring pack. I always though the opposite. In extreme opposite, setting it on a pencil set sideways seems like it'd wrap horribly. Yeah, more leverage but you're further out on the lever so less force... Link to comment Share on other sites More sharing options...
feerocknok Posted August 9, 2006 Share Posted August 9, 2006 I've seen where longer spring perches induce spring wrap, more leverage on a thinner part of the spring pack. I always though the opposite. In extreme opposite, setting it on a pencil set sideways seems like it'd wrap horribly. Yeah, more leverage but you're further out on the lever so less force... Agreed. Link to comment Share on other sites More sharing options...
Eagle Posted August 9, 2006 Share Posted August 9, 2006 mopar performance perches.Available at your local dealership. $8 a PAIR. They're beefy, meant for the musclecar group, larger than the stock d35 perches. PN DCC-4120074 You beat me to it. This is definitely the sleeper parts listing of all time. When I set out to order a pair of these things, the parts guy looked up the price, we looked at each other, and said "That CAN'T be for a pair." So I told him to order me two, just to be safe. So he ordered me two, and the next Saturday morning I stopped in to collect my swag. He set two boxes on the counter, and they rattled. We opened one, and out came TWO of the beefiest spring perches I ever saw. They are WAY heavier than the OEM perches that get welded to an XJ axle, and much better quality than what you'll pay the offroad suppliers $30 to $50 a pair for. Link to comment Share on other sites More sharing options...
Hot Rod Jeep Posted August 9, 2006 Share Posted August 9, 2006 I'm getting ready to set my rear under my truck and I'm also going with 2x3 tubing. I got a couple already made from a friend and they're about 8 and a half inches long I think. I was just curious how long you guys made yours. 8) Link to comment Share on other sites More sharing options...
Regger Posted August 9, 2006 Share Posted August 9, 2006 I'm getting ready to set my rear under my truck and I'm also going with 2x3 tubing. I got a couple already made from a friend and they're about 8 and a half inches long I think. I was just curious how long you guys made yours. 8) The ones that I made for the girlfriends truck were 8" long.. and after 3yrs, have had zero axle wrap and zero problems... The ones planned for the MJ SOA are also 8" long... That should do well for you.. HTH Ryan Link to comment Share on other sites More sharing options...
Bounty Hunter Posted August 9, 2006 Share Posted August 9, 2006 The axle is going to twist regardless, but adding a long lever (long spring perch) is going to increase the distance the end of the spring perch travels horizontally. Add this to transferring the torque to a thinner part of the spring pack and there you go. With a long spring perch, only the amount of leaf pack outside the perch is absorbing any axlewrap. Couple this with the ends of the pack being thinner, and you suffer the consequences. Shorter spring perch means you have the entire spring pack to absorb wrap, even the thicker part of the pack. I used to think longer perches were better, but I think they just limit spring movement and place more stress on a thinner part of the pack. Link to comment Share on other sites More sharing options...
Regger Posted August 9, 2006 Share Posted August 9, 2006 Bounty Hunter, I have to dis-agree with you on this... Axle wrap is caused by the spring going into a "S" shaped pattern.. And this is caused by the very small contact point on the spring perch allowing the "S" shape to be produced.. By increasing that point of contact, it is a lot more difficult for the spring to go into the "S" shape because it has such a large flat spot preventing it... The "S" is only created from the end of the spring perch to the eye bolt.. The longer that distance the easier it is to "S". By having a longer spring perch, you are reducing that length, there by making it harder to "S"... Its known, that the shorter the spring is, the less axle wrap you get.. and vice versa, the longer the spring, the more axle wrap. So in a sense, by making your spring shorter with a longer perch, you will reduce axle wrap.. AS for transferring torque to a thinnier part of the spring... I don't get you on this... The only spring that is tapered is the overload spring... The rest of the springs in the pack are of equal thickness throughout their length.. And even at that, a 2" difference in length along the overload, I measured at only a .030" thickness drop... So its not even enough to be concerned with at all.. AS for limiting spring movement... this would only happen if you are negatively arching your springs... at which point the overload is going to cause more force on the spring to bend that way, then a longer perch would.. And as for MJ springs, they have so much arch in them, that I don't see how someone could negatively arch their springs, without stuffing the tire into the wheel well firts.. Unless they are running really small tires, then maybe.. BUt who runs a lift with small tires anyways???? :nuts: My girlfriends S-15 Jimmy has been running 8" long spring perches for 3yrs now with zero axle wrap. And in comparison, a buddy just put s-15 springs on his toyota pick-up with a stock perch (~4" long) and he has a serious amount of axle wrap.. SO that is my real world experiance to back up my statements above.. THat is as cloce of a comparison I can get without cutting off the 8" perches and putting stock ones back on and measureing the wrap then.. which I don't want to do... And everyone and everywhee I have researched has backed me up on longer spring perches help axle wrap... YEs you can have too long, but where only talking 4" longer than stock... So unless there is a whole other realm of info that proves me otherwise.. I'm sticking to what I know... Thats my thoughts, and that is why the MJ has 8" long perches for the SOA its getting Thanks, Ryan Link to comment Share on other sites More sharing options...
Hot Rod Jeep Posted August 9, 2006 Share Posted August 9, 2006 Thanks for the info guys. :cheers: 8) Link to comment Share on other sites More sharing options...
Pete M Posted August 9, 2006 Share Posted August 9, 2006 :needpics: Link to comment Share on other sites More sharing options...
Regger Posted August 9, 2006 Share Posted August 9, 2006 Pete, don't know what pics your looking for.. but the only one I have is of the G/F's perch when we did SOA on her jimmy... HTH Ryan Link to comment Share on other sites More sharing options...
Pete M Posted August 9, 2006 Share Posted August 9, 2006 I was thinking more of diagrams with arrows and forces and such. :teehee: Link to comment Share on other sites More sharing options...
Regger Posted August 9, 2006 Share Posted August 9, 2006 Ahh, your trying to get technical now eh...????.. Well I'll see what I can come up with on my end.. but it might not be for a few days.. have a busy week and weekedn ahead... I'll see what I can do.. Thanks, Ryan Link to comment Share on other sites More sharing options...
Pete M Posted August 9, 2006 Share Posted August 9, 2006 I'm just now walking out the door for a camping trip and won't be back 'til Saturday, so take your time. :D I figure a diagram might help everyone describe their thoughts better. Link to comment Share on other sites More sharing options...
Bounty Hunter Posted August 10, 2006 Share Posted August 10, 2006 Bounty Hunter, I have to dis-agree with you on this... AS for transferring torque to a thinnier part of the spring... I don't get you on this... Thinner part of the spring PACK. And as for your vehicle comparison, comparing apples and oranges. Not saying you're wrong, just throwing out an alternative viewpoint for discussion. I used to think along your line, but have recently been looking at it a little differently. I think any excessively long spring perch will limit spring movement, I don't think you can have it both ways. Link to comment Share on other sites More sharing options...
Regger Posted August 10, 2006 Share Posted August 10, 2006 Thinner part of the spring PACK. I still don't understand the how the spring pack is thinner 2" back from the stock perch.. Yes it might be thinner by about .030" due to the taper of the overload, but in the picture I posted... I don't see how the pack is thinner... Maybe another 8" further back where the 4th leaf ends, ... Sorry, maybe a hard measurement to show the "thinner" difference your talking about.. And as for your vehicle comparison, comparing apples and oranges. HOw so.. a leaf spring setup is a leaf spring setup no matter what vehicle.. Where both talking about SOA setups, in which no matter what vehicle its in will still generate torque to twist the springs... I figure the Jimmy is as close to the MJ as you can get since it was SUA, it is now SOA, it also sports the MJ's D35, the rear ends weighs only 500lbs more than an MJ's, and it has a 6cylinder powerplant.. pretty damn close to a MJ setup if you ask me.. Not saying you're wrong, just throwing out an alternative viewpoint for discussion. I used to think along your line, but have recently been looking at it a little differently. .. oh No, I love a good discussion.. cause hell, if I've been believing something wrong all these years, I sure would not want to keep on believing it, cause what I believe I pass on to others that ask for my advice... but I need some solid evidence and proof that my thinking is wrong before I switch thinking... I think any excessively long spring perch will limit spring movement, I don't think you can have it both ways. I agree that an excessively long perch will hinder suspension compression... but in excessively long, I would say like 12" long or longer.. but not 8" long where your only 2" longer each side of stock.. And in the Mj's case, the spring has such a large arc to it, that for the spring to negatively inverse to the point its bending around the spring perch, it would have to bend well past the stock bump stops and further... Now if we were starting out with an already flat spring at ride height... then yes i agree that a longer perch would not be best as the spring will negatively bend under normal suspension travel, and not under huge flex situations. Pete, as for pictures you requested... I'm trying to get a buddy at work to create a force diagram drawing based on a SOA leaf spring setup.. so we'll see if he will or not, unfortunetly, I don't have high hopes for this... It sure would be nice though.. Thanks, Ryan Link to comment Share on other sites More sharing options...
DirtyComanche Posted August 10, 2006 Share Posted August 10, 2006 I could draw you a FBD. But, I won't, because you guys are arguing spring perches. And I don't have the time to read all of that... I can tell you from experience ONLY that as long as they are the same length as the spring plate or slightly longer, you won't have any spring wrap. That's also providing that you have the actual springs setup right (the BIG part of the equation). Link to comment Share on other sites More sharing options...
Oizarod115 Posted August 11, 2006 Share Posted August 11, 2006 That's also providing that you have the actual springs setup right (the BIG part of the equation). does the stock pack not do well SOA? or is it just best to bastardize it.. cause id really rather not bastardpack it if i don't have to.. one more thing to mess up. Link to comment Share on other sites More sharing options...
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