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Shackle flip and towing

Discussion in 'The Garage' started by dammit32, Jul 5, 2004.

  1. dammit32

    dammit32 1/2 ton status

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    Hey
    I did a shackle flip with F*rd 57" springs a couple years ago and now I have the need to tow some medium weight trailers with my rig. I used the Echobit kit and was wondering if there was a quick fix or if I need to find some stiffer springs again . The flip does great off road but when I hook the trailer to it the nose goes up so far that I can barely see over the hood LOL. /forums/images/graemlins/1zhelp.gif
     
  2. BlueBlazer

    BlueBlazer 1/2 ton status

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    The short wheelbase and soft springs are whats hurting you, not the shackle flip.
     
  3. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I disagree. The nature of a shackle flip creates a condition that is not well suited to towing. Tension style shackles are on heavy duty trucks for a reason, and it's not because they wanted to run higher arch springs.

    I would not tow with a shackle flip unless it was an emergency. The only way I'll ever tow ANYTHING with my truck is if the tow rig breaks down and I have no other choice but to roll the trail machine off the trailer and winch the tow rig up onto it, which I would consider an emergency.

    We can go back and forth on this issue, as stated above, short wheelbase and soft springs make this even scarier, but a shackle flip no matter what you have for springs is really not well suited to towing at all.

    Leave the towing to the 130+" wheebase rigs with heavy duty suspension and tension style shackles.
     
  4. BlueBlazer

    BlueBlazer 1/2 ton status

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    God damnit man, weve gone through this before and a majority of people "in the know" agree that a shackle flip alone does not made a bad tow vehicle.
     
  5. Fry

    Fry 1/2 ton status

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    if towing was a routine thing I would say slap some air bags in the rear. But for a one time type of towing I wouldn't know what to suggest.
     
  6. BlueBlazer

    BlueBlazer 1/2 ton status

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  7. 84_Chevy_K10

    84_Chevy_K10 Banned

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    That looks like a straight truck frame to me. I don't see any trailer hitches.

    Besides, how do you think you can compare a truck with a 21,000 lb GVWR that isn't towing anything to a truck with a 6,000 lb GVWR? /forums/images/graemlins/rolleyes.gif

    What backwoods, hillbilly ass line of thinking is that, really? What logical line of thinking tells you that because THAT rig has compression shackles, it's automatically a safe towing modificaton?

    The exact reason that a shackle flip is good off road is the reason why it is not well suited to towing.

    You can disagree, and that is fine. But to say that my point reguarding shackle angle and spring rate with relation to shackle flips is not valid is uneducated to say the least.

    Whether you think that a tow rig should have a shackle flip or not you cannot deny the effect of shackle angle on spring rate.
     
  8. BlueBlazer

    BlueBlazer 1/2 ton status

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    Whatever man, you can NEVER be wrong, so I wont waste any more of my time /forums/images/graemlins/rolleyes.gif
     
  9. Z3PR

    Z3PR Banned

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    There are more then a few members here with shackle flips that tow. I personally haven't towed with the shackle flip, but I've read that some people do.
     
  10. 84_Chevy_K10

    84_Chevy_K10 Banned

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    [ QUOTE ]
    There are more then a few members here with shackle flips that tow. I personally haven't towed with the shackle flip, but I've read that some people do.

    [/ QUOTE ]

    Yes, there are. I disagree with what they were doing. That doesn't make me or them wrong, that just means I wouldn't do it.

    When are people going to realize that not everybody agrees on one subject? What is with the whole idea on this board that if you disagree, you're either a jackass, you don't know what you're talking about, or whatever? Why do we expect everyone to agree here?

    If we all agreed about everything, all of our trucks would look the same, be built the same, and be the same color, etc. That would be really gay in my opinion, the whole idea of being intelligent has something to do with making decisions for yourself and not going along with everything that everyone else says.

    I'm so tired of this, but I'm not going to continue to rant here, I'm going to start a post in the lounge where this discussion belongs.
     
  11. mrk5

    mrk5 The Sticker Guy Moderator Vendor GMOTM Winner Author

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  12. miniwally

    miniwally 1/2 ton status Premium Member

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    Towing with a Shackle Flip is FINE use the correct equipment to tow and all will be ok.
    I.E. a blazer that is lifted 4" with 37" Tires is going to tow like dog SH%T. I don't care what your lift method is.

    Tim your village misses their idiot
    GO BACK
     
  13. marv_springer

    marv_springer 1/2 ton status

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    Towing w/ shackle flip => fine...

    Towing w/ 57" Ford springs => prolly not fine...

    Add some airbags or booty up some coil spring mounts (for coils that you can remove later..) /forums/images/graemlins/thinking.gif

    Marv
     
  14. jjlaughner

    jjlaughner 3/4 ton status

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    [ QUOTE ]
    I disagree. The nature of a shackle flip creates a condition that is not well suited to towing. Tension style shackles are on heavy duty trucks for a reason, and it's not because they wanted to run higher arch springs.

    I would not tow with a shackle flip unless it was an emergency. The only way I'll ever tow ANYTHING with my truck is if the tow rig breaks down and I have no other choice but to roll the trail machine off the trailer and winch the tow rig up onto it, which I would consider an emergency.

    We can go back and forth on this issue, as stated above, short wheelbase and soft springs make this even scarier, but a shackle flip no matter what you have for springs is really not well suited to towing at all.

    Leave the towing to the 130+" wheebase rigs with heavy duty suspension and tension style shackles.

    [/ QUOTE ]


    I'm going to agree /forums/images/graemlins/rolleyes.gif with Tim on this one. /forums/images/graemlins/doah.gif
    When a spring is pushing up on the std spring hanger it holds the spring in a manner where the spring rate is being used. In a shackle flip in which the shackle is angled back slightly I think you loose the spring rate of the spring... thus allowing more flex but also the use/direction of the spring has changed.

    Reguarding the pic above of the shackle flip on the 21K truck. It doesn't look from that image that, that setup has changed the pinion angle, spring angle or lowered the rear mount, the shackles also look vertical. I could see in a situation of a large vehicle with a vertical to slightly forward shackle angle so that when weight it applied the shackle moves to a straight up and down position allowing for maximum use of spring rate.

    The point Tim is trying to illustrate is that with the spring setups in the our style trucks when you lower the rear eye mounting location 4-6" you are no longer using the spring to its wieght rating because you have shifted the mounting position of the spring cutting the spring rate of the spring. This idea PLUS the rerevsed shackle angle, I could see the potintal for issues when hauling large loads. If your pulling a 16' fishing boat, go for it! If your pulling a trailer witha vehicle on it... thats seems like a scary setup, TO ME.

    BUT! on the otherhand, as with anything on this site, there are people that use these setups and it works for them. /forums/images/graemlins/dunno.gif Just like some people run D44/12bolts while others run D60/14b-D70.

    eitherway, I'll tow with my /forums/images/graemlins/k5.gif that has 4" rear lift springs, but towing anything larger than a small trailer or boat with the project rig (with a shackle flip)... I think I'll use a different vehicle. /forums/images/graemlins/deal.gif
     
  15. BlueBlazer

    BlueBlazer 1/2 ton status

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    The ORD shackle flip sets the shackle angle at or very near perfectly vertical. The only times I see an angle back there is with a homemade flip or one of those goofy Echobit flips. The thing you guys do not seem to understand is that the reason a truck with a shackle flip is more unstable is simply because you are lifting it above the factory height and a higher COG makes for not as stable experience with towing.

    I really don't buy into this shackle angle making as much of a difference as everyone thinks. Look at this this way: If a leaf spring has say a 500 lb-in. rating to it, that value was derived using rollers at either end of the spring to almost eliminate friction when the spring is loaded up. However, when you put bushings at either end that have a bolt crushing it at 90 ft lbs or so, and a dead spot in the middle where the ubolts are, you effectively raise the the actual spring rate quite a bit. So maybe a 500 lb-in spring might be an actualy 750 lb-in (or whatever) in a truck. This might actually be much higher because anybody who has put the weight of their vehicle on the springs before the eye bolts are tight knows that the spring moves much more free. So putting a shackle flip on does change the actual spring rate a little, but it really depends a lot on the spring. A 57" Ford spring might make quite a difference since the spring rate is already so low, but on a 3/4 or 1 ton truck that most use for heavy towing, where a very heavy leaf pack is used, the difference will be minimal since it takes a lot to move the springs to a point where the shackle angle starts to lower the actual spring rate to any degree.

    In short, making a blanket statement saying that a shackle flip is bad for any towing is not wise. Basically, if you got soft springs in back and want to tow, you need to get heavier springs. If you already have heavy springs and want to use a shackle flip AND tow, go for it, I plan to as soon as I get a trailer and I know I wont have any troubles. I can already tell when I load it up with scrap that it does not even squat at all in back and rides very comfortably. Basically, those that say that shackle flips themselves are bad for towing need to get a clue.
     
  16. 84_Chevy_K10

    84_Chevy_K10 Banned

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    The main point here is that if you have soft springs to begin with and you do the shackle flip, you now have even softer springs. A K5 is a crappy tow vehicle to begin with but super soft springs plus a shackle flip it will be an absolute nightmare.

    Y'all can dismiss the effects of the shackle on the spring all you want, you're foolish to believe it has a minimal effect.

    Idiot or not I would not tow with a shackle flip. If you want to that is your business. But in my opinion a truck with lift springs or blocks is far safer than any shackle flipped machine for towing.
     
  17. jac6695

    jac6695 1/2 ton status

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    I used to often tow a 23' travel trailer with my K5 with a homemade shackle flip (using factory spring hangers) that essentially duplicates an ORD setup. I towed the trailer with all of the proper towing equipment (load equalizing hitch w/sway control) and had GM 56" springs from a 3/4 ton truck. I had absolutely NO problems with this setup and noticed no difference in towing before compared to after the shackle flip.

    I usually ran 33" load range D tires, though occasionally used a set of 35" LR D tires, and in fact, blew a right rear 35" at about 70 MPH once towing the trailer and the truck stayed very stable and in control.

    I agree that the Furd 57" springs are very soft and will change the handling of a Blazer all by themselves. The shackle flip is not a problem at all, if the truck/trailer are otherwise set up properly for towing. I ran the K5 with the same shackle flip with GM 64" springs from a 1/2 ton truck, and noticed a change in handling due to the softer, longer spring. The truck towing the same trailer was still stable and safe.

    Towing with a K5 is a bit like driving a Samurai. 60 Minutes proved they will flip over, but if you remember you are driving a Samurai, and not a Corvette, chances are you won't have any problems.

    Tim, understand that we actually listen to your opinion, but remember, it only YOUR OPINION! You have a lot of knowledge, and sometimes you have some good points, but dude, you need to know when to back off sometimes.
     
  18. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Yes. There is no proof that I'm right on this. I just want to state both sides of the coin. Watson insists that it's safe and he's an engineer. He certainly knows way more than me and he still thinks it's safe so that should say something. I just think that the nature of the design makes it less safe than a tension shackle. With that said there are much more unsafe tow rigs out there, I just feel a tension shackle makes for a safer tow rig.

    I never said anyone else was wrong for thinking that it is perfectly safe to tow with a 'flip. Hell, it probably is. I am simply stating my opinion, which I don't think I'm an idiot for having. I just disagree on a truck related issue.
     
  19. Pookster

    Pookster 1/2 ton status

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    Tim, I kinda agree with you here, on many points- since I myself have an echobit flip, I cannot vouch for towing on ORD's flip.

    I do recall the towing issues that Grim Reaper had (and his near death experience) and that has always stuck with me. I only had my K5 as a tow vehicle, so I had to tow with it- I got a 7700k rated tadem axle trailer, with a 6" drop hitch to make everything level, and loaded it up with approximately 350-400 lbs of tongue weight, as recommended.

    Springs were stock springs, just with the echobit flip. Front springs were pretty stiff.

    For people to say that the springs arent soft, I dunno, maybe it was just mine. Even under normal driving, hitting bumps make the rear springs move a lot. I can see it even in my own reflection driving over a speed bump.

    In regards to towing, what a white nuckle experience- Every bump in the road, caused my rear end to move up and down- execentuated (sp?) by the tongue weight. This wouldnt have been so bad, but I also have a bit of bump steer- So as the end moved differently than the front, it would cause bump steer. Somtimes it got so uncontrollable, that I thought I was gonna loose it from sway- Since even a little sway of the front truck (since I have no rear sway bars, the rear of the truck could tilt a littlr from left to right. the number of times I reached for the emergency trailer brake just to straighten out.... I towed like this several times, Each time believing that it had to be this whole "short wheel base, k5 suck at towing" etc etc....

    Of course, after seeing so many pathfinders, x5's and troopers tow the same sized trailer and the same loads without issues- I started looking at why they could do it and I couldnt- my only conclusion was that:

    IFS and SFA's dont really matter too much- IFS wins by a little, since it isnt as prone to bump steer and handling is better.

    Rear IFS and SF in the rear, IFS acutally wins by a little as well, as independent road variations on one side dont really transfer to the other- but thats not a good comparison point either.

    What I did find is in most of these other vehicles-
    1. mostly stock
    2. stock comes with rear sway bars

    and the most important thing I found is, that the effective spring rates ar ematched- going over a bump with the front of the truck is the same as going over a bump with the rear- It doesnt travel 1" in the front and 3 inches in the rear. that is the single biggest issue with a shackle flip. In my case, the sway bar in the front, plus a stiffer spring yielded in more travel in the rear of the truck than there shoulda been.

    Here are some solutions: Air bag. if you can get one to reach long enough this helps a lot.
    Helper Spring shocks- These add load carrying capacity by making your shock also have a coil over spring- its actual effectiveness i cannot verify.

    Weight distribution/anti sway bars- These are what i went with, and towing has been night and day-. What used to be a white nuckle 50mph in the right lane.. I can now do 80mph and be in total control. I can now cruise nicely at 65mph, one handed, with semi's passing me, and i dont feel like im being pushed around or anything.

    You can get higher WD bars, and this may help your towing dramatically. Try towing for like 20 miles with your current setup. Then if you can, borrow a buddies trailer/WD setup and see how ya feel.

    oh yeah, back to that whole shackle over/under thing- I dont think a 21000 lb truck design qualifies in the same field- Their spring packs arent the same as ours, and was designed to work with that design.
     
  20. Stephen

    Stephen 1/2 ton status Moderator Vendor

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    [ QUOTE ]
    Yes. There is no proof that I'm right on this.

    [/ QUOTE ]

    Yup, but there is proof that you are wrong about this. This is a technical point of fact so there is no room for opinion, just facts about how a shackle system works.

    A tension shackle produces a naturally rising spring rate at the very limits of the spring's travel. Basically as the spring compresses past flat and starts to go into a negative arch, the eyes will start to get closer together. As the eyes try to draw together, the tension shackle has to swing forward on it's arc and (depending on the specific spring length and angle of the shackle) since forward for a tension shackle means it has to rotate down, you get a huge rise in rate. Basically the shackle is trying to pull down on the spring while the axle is trying to push up on it and the system freezes itself up.

    With a compression shackle, you get the same effect as the spring tries to flip over flat because as the eyes try to draw together and pull the shackle forward, the shackle swings down which tries to force the frame away from the axle while the axle is trying to push closer to the frame, creating a rising rate.

    It's not quite as easy as it sounds because both situations depend a lot on the shackle angles, length of the spring, rate, capacities, bumpstop placement, etc. I have pages of charts showing all these details and believe me, they are well worn pages.

    In our case, a soft "trail" spring can compress into a negative arch where this becomes very relavant but a HD stock type load carrying spring has a hard time going past flat because of the overload leaves so when using a spring designed for a heavy load, the rising rate isn't a huge deal. But this rising rate effect at the fringe of the compression travel is one of the factors that makes a spring system work well for any load carrying task which is really all that towing a trailer is, as far as the spring and shackle are concerned.

    This isn't the first time I've played with this, our shackle flip is built the way it is for some specific reasons and these are some of them. Shackle angle is important in any spring design solution.

    All things totalled up, the overall package is what makes a tow rig work. You have to have a good trailer because a trailer that bounces all over the place is going to be miserable. You have to have good shocks with reasonable leverage against them. You have to have a stiff enough spring to handle the tongue weight without excess ride height changes. You have to have a stiff enough tire to handle the load without excess squirm or bounce.

    Have I heard all this before? It's like deja vu all over again.
     

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