I need some leaf spring help

Tyson

Well-Known Member
look at thes pictures. I need help. I now have the ride height that I want, however the truck now sits a full bump.

Only thing I can think of is to, well first I know I need to reconfigure the fuel cell cross brace. BUt, also I know I need a longer shackle. any advice???
H E L P

*NOTE* the actual military wrap IS NOT sitting on the frame, nor can it touch the frame. It hits the cross bar of my fuel cell, before.

<IMG SRC="http://www.geocities.com/yotapunk/tysonshackleleft.jpg[image]



[IMAGE]http://www.nethirdgen.org/ubb/graemlins/headbang.gif"> <font color=red>&lt;--ME IN MY TRUCK
 

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Tyson

Well-Known Member
the shackle hit this bar, if you can see it. This pic also shows the old shackle location, pretty far back huh?

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cleartoy

Well-Known Member
Not sure i understand the problem. it looks like the shackle will hit the frame on compression. Either add a longer shackle, or change the shackle mount.

85 Toyota xtracab 4x4(for sale)
94 Toyota stdcab 2x4
99 Yamaha YZ250

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Tyson

Well-Known Member
Sorry, the problem is, is that I have no up swing in the shackle. The last picture shows the "old" shackle locations (through the frame) now it is mounted on top of the frame and in the right spot. However, the bar directly behind my fuel cell stops the shackle completely, about 1/2 an inch before it can hit the leaf on the frame. (I'm still gonna put a rubber bump in there on the frame)

So will a longer shackle give me some up swing? and will it also lift the ass end back up? Cause that is what I am trying to avoid. I was hoping to get some 62's and like a 12 inch shackle and then "possibly" it would clear the end of the frame.

Any thoughts???


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rdc

- users no longer part of the rdc family -
That shackle needs to be mounted uderneath the frame. It is naturally going to want to travel rearwards out and away from the opposing pivot point. You are going to be the victim of EXTREME spring binding, and on of two things is going to happen; 1. Spring will break, or 2. you will shear off or damage the front spring hangar. You will also subject the bushings to enormous loads, deeming them fouled in a very short period of time.
 

Tyson

Well-Known Member
K, well what would be the proper way of mounting a shackle on top of the frame. I've seen alot of trucks with the shackles on top of the frame - is there a correct way? If I mount these on the bottom of the frame its going to pick up the rear end alot right??

Thanks for your help

<font color=red>&lt;--ME IN MY TRUCK
 

rdc

- users no longer part of the rdc family -
Another disadvantage to the shackle being that high is your anti squat characteristics....in that position, the rear of your truck will actually try to lift versus drop, which is what you do not want in the dirt. Dragsters utilize anti squat, usually well over the 100% mark, if not , the would bury themeselves in the race strip. The problem with the rear ride height is a burden to all toyotas. The only way to over come it is with weight, and to take some arch out of the spring. I had a toyota with 62" springs, and I ran two spares, a jack, and a 32 gallon cell to overcome this, and took three inches out of the arc. You can also take some springs out of your pack to decrease the spring rate...depending on how many springs you have in your pack. These things are a little complicated, aren't they?
 

Tyson

Well-Known Member
yeah these things are quite dificult. How it was set up before I had to run my 32 gallon cell and (at the time only 1 spare) now I have mounts for 2 but weight won't help my current ride height problems. the Leafs that I'm running right now are Nationals. They were a pack of 12 but I pulled out 5 leafs and it ran good in the rear except for the ride height issues.

So if I'm understanding you correctly right now you're saying that even running a longer shackle is WRONG?? Sorry for my ignorance but won't 12" shackle mounted above the frame act very similiar to an 8" shackle mounted underneath the frame? The way I was looking at it was that with a longer shackle I was giving myself some "up swing" on the shackle with out bottoming it out on the frame but instead on the bump stops above the rear end. Possibly even give me MORE droop when I'm in the air cause then I'd have a longer shackle holding the leaf (I know I'll need limiting straps)

and I'm not familiar with the squat charastics. . .is that referring to the fact that the leafs are not actually at full bottom. . .bot rather stopped in their tracks so to speak. Is that where my problem lies, if so how do I fix it?

Sorry, I've tried sooo many different configuration with these leafs. Kind of at the end of my rope with them, but I was thinking a longer shackle then I could weigh down the rear end to pull out the arch. . . and get the ride I want.

<font color=red>&lt;--ME IN MY TRUCK
 

rdc

- users no longer part of the rdc family -
Lets not worry about the anti squat.........we need to get that shackle underneath!....A longer shackle on the upper mount wont resolve anything....you should stick with an 8" or so underneath the frame for maximum results. Another quick note is on how the shocks are mounted on the truck. It looks like they are on a 1 to 1 ratio....so if we a re looking for more travel out of the rear, we need to get some angle on those shocks, depending on what size springs you are running, you should be able to get atleast 17-20" out of the rear.....let me know if you need help on how to figure out how to achieve this...
 

Tyson

Well-Known Member
ACTUALLY, the shocks and my whole bed cage will be cut off and my fabricator is going to redo the whole thing since there is a few things wrong with my set up. (Another guy built it) It will all be redone when I get some 18" travel shocks back there and the cash for my cage.

So then you are saying that all the Toyota's I've seen with shackles on top of the frame is wrong? What about through the frame? I guess I'm just unclear as to why it's wrong and why it will destroy my bushings, bind my leafs, and/or tear apart my front hangars?

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rdc

- users no longer part of the rdc family -
Leaf springs transmit acceleration and braking forces, so therefore their positioning and configuration is critical. Basically, you must give your springs a FULL RANGE OF MOTION in order to achieve desired results. An analogy for you...springs under the frame are like a door on a hinge, full range of motion till it "bottoms out" on a wall. Now with shackles above the frame, its like a door with the hinges in the middle or so, you will never be able to open it all the way.....and for the unsuspecting individual passing thru that door, (being your leaf spring), they will hit that door with force enough to rip it of its hinges (leaf hangars) or break the door (leafs)
 

Tyson

Well-Known Member
K- Obviously I need full range of motion. I knew that this set up is not exactly optimal, which is why I posted a question in the shop board on race dezert. Sounds like though you'd rather make me look like I don't have a clue what I'm talking about, so I'll seek advise from someone willing to give helpful advise - not useless comments. Thanks for your time, I'll put what information I did get from you into consideration.

Anyone else know anything about mounting shackles about the frame, since that is where they are. Is there anyway I can accomplish usable travel as well as low ride height, without cutting inot the shackle mounts again?

Thanks,

Tyson

<font color=red>&lt;--ME IN MY TRUCK
 

rdc

- users no longer part of the rdc family -
i'm sorry if i have wasted a whole evening with useless comments,and I apologize if you percieved them as such. I deal with suspension problems on a daily basis, its my job, and I enjoy it, and I enjoy helping people in the sport, and if it helps you out any, I will send you an message of some people who can maybe give you the answers you are looking for. Good luck Tyson.
 

firedog

Well-Known Member
Hey Tyson, go easy on BLUEDOG aka Nick. I know him personally and he isn't trying to dog you or anything! Listen to what he is saying. He has been in the off-road business for a long time and worked with a-lot of BIG named teams and helped them with their suspensions and getting them set up the correct way. He has even taken the time to help us with our stufff on our 7s truck. Believe me he is just trying to help you get the most out of your truck by offering his advise and expertise.
 

heavy8

Well-Known Member
Im far from and expert fabricator but from the pictures it is obvious the shakle pivot point needs to come way back. About so that the shackle is verticle at ride height. I would take out the full cell and, anything else in the way then take the spring pack apart down to the primary spring and use lift/lowering block to make up the thickness of the leafs that were removed. Next cut off the upper shackle pivot point and tack it back on in about were the shacklle is at vert at the givin ride hieght you want. Then cycle the suspension till you get it right, once you are able to cycle it everything you are not sure of will come clear..also the shackle lenght and kick might need to be changed as well...
Good luck ......

call up deaver and ask for there recomedations on the shackle length for the length of springs you have as well..
 

Jkrell

Well-Known Member
Yota 602, chill out man bluedog has been giving you sound, patient, hold your hand advice all night. say thanks! and if you dont understand ask more questions.

Here's my experience for what its worth...

The rear of my truck has the shackle pivot mounted in the middle of the frame with a 6" shackle. Its a pretty short leaf with only about 14" of travel in the rear but I have had no problems with bushing wear or leaf spring breakage, and thats with about 20,000 street miles and about 1000+ offroad miles. Additionally the truck handles very well on the street with this setup. I am not sure of all the engineering behind anti squat and dive but with the shorter shackle setup through the frame the truck rails the corners. The truck has always sat up a little bit in the rear, but I never cared much since it worked and handled well.


? for BlueDog, I currently have 55" leafs on my toyota (old school setup before 62's were the rage), I plan on installing a set 62 inch leaf in the not too distant future in order to keep up with the new duffco front suspension I installed recently (good for about 14" of travel), and I was hoping to use the shorter 6" shackle (mounted under the frame) to keep the rear end down somewhere around where it currently is, will that work or should I just make the longer shackle, also, what kind of travel can I expect out of that setup. I think I would be pretty content with 17 or 18". Also, currently I am running dual 14" stroke shocks, Can I make these shocks perform properly with the increased travel, I realize I will probably have to move around mounting points but what is it going to take to make the shock perform properly. Also, I noticed on yota's 602's truck and on other trucks the bent shackle. Do you know the advantages/disadvantages of it, and is it worth messing with on this setup.

Thanks for help.
Jon.
 

Jkrell

Well-Known Member
one more thing to yota 602's defense. The MacPhersone 7s truck, now the S&S truck, has the shackle pivot above the frame with a really, really, long shackle ( much longer than 8", I think), and that truck is probably the fasted mini truck in the dez, but then again that truck is pretty highly engineered ground up and has all kinds of crazy stuff on it, also it is a chevy so the frame is differnt. I dunno.

Jon.
 

NorCal_Prerunner

Well-Known Member
My 2 cents.

Are the springs just too arched for your application?

Deaver suggests a 10 - 12" shackle to acheive 18"s of travel, mounted in the frame for 62" spring mounted under the rear axel.

Whether you run the shackle below, in, or on top, you need to locate the rear eye of the spring farther away from the frame. Result, increasing your ride hight. I know you don't want to do that. That brings me back to, are the spring too arched for your application intended for more lift than you want?

Advantage of the longer or bent shackle is that it will create more swing at full droop mounted in or on top of the frame, resulting in more travel, without excessive lift.





jnie
 
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