ladder bars for a quad cab?

[jmm756]

I have the turbocharged 5 speed 4x4 quadcab, getting some serious axle wrap when i try to burn the big meats i have. wondering what you guys thought or suggest for ladder bars?

[HemiDak]

I get it badly too. I'm going to have a friend (welding engineer) make up some custom hidden traction bars.

They're going to be like this, but hidden more and up out of the way.


http://loudzr2.homestead.com/Bars.html

[jmm756]

I'm looking for something i can buy and just bolt on. I want to get it on the truck before i go back to school on the 8th. If anyone has a good one to go with please let me know. thanks

[jmm756]

anything for a 2000 of newer dakota

[fastdak]

their not ladder bars , but lakewood traction bars stopped the wheel hop i had. their what ya call slapper bars. bolt to the axle and a rubber snubber sits just under the front spring perch. i think i payed $ 40 for them at advanced auto. you can see one sticking out in front of the tire in the picture. cured all my wheel hop and i jumped really bad. even in the snow!!

[HemiDak]

Slapper bars are for spring under and not spring over. Since we're both 4x4's, we have spring over. Slapper bars wouldn't work.

There isn't any pre-fab bars out there for Dakotas as in Ladder bars. I wish there was or else I'd be buying a set too.

[Bob Sheaves]

I get it badly too. I'm going to have a friend (welding engineer) make up some custom hidden traction bars.

They're going to be like this, but hidden more and up out of the way.


http://loudzr2.homestead.com/Bars.html
ummmmmm....really, REALLY bad idea. Those band-aids cause more suspension problems than they solve. They bind up spring travel (by forcing the axle through an arc that is rigid, rather than the parabola the forward half of the leaf defines, you will at some point in time, break the eye off the main leaf), alter the suspension anti-lift designed into the leaf travel (co-incidently, also altering the rear steer characteristics of the axle in roll), and finally, they induce a bind in the driveline, possibly over extending the travel of the rear u-joint, due to the different axle rotation path as the axle goes from jounce to rebound.

Best as always,

Bob Sheaves

[jmm756]

well dude for those of us who can't leave things alone, the stock springs just aint cutting it for my 500+ft lbs 5000lb dakota. The rear springs get twisted up so bad its rediculous. The slapper bars will help keep my springs from really distorting under the sevear load the axle provides, causing a greater spring life. added leverage for the spring to do what its suppose to do, not deform that parabola shape.

Mechanical Engineering student at penn state erie.

Simple also i have gone through two sets of rear u joints since turbo install, to much of a bind when i wind up those springs. the slappers will prevent this when i want to burn rubber. The wheel hop has also caused me to almost loose control when sliding sideways, sometimes it grabs sometimes it slides, charictaristics go to shit with that much power. A nice smooth sliding rear tire burn will allow more control. For a $60 addition to the rear it dose wonders for the life of rear drivetrain and suspension. :sorry:

[jmm756]

I guess i'm going to have to build a set for myself. probubly just extend the place it bolts onto up to the spring. so where the bar bolts onto the spring in the back, lower it down to clear my rear housing, and weld some longer pieces to reach the fram. or i could put it on top of the spring, and have it face back, but alot of force would go on the shakle then. since i don't offroad i will stick with the first way i think. just put it under the axle tube

[Bob Sheaves]

well dude for those of us who can't leave things alone, the stock springs just aint cutting it for my 500+ft lbs 5000lb dakota. The rear springs get twisted up so bad its rediculous. The slapper bars will help keep my springs from really distorting under the sevear load the axle provides, causing a greater spring life. added leverage for the spring to do what its suppose to do, not deform that parabola shape.

Mechanical Engineering student at penn state erie.

Simple also i have gone through two sets of rear u joints since turbo install, to much of a bind when i wind up those springs. the slappers will prevent this when i want to burn rubber. The wheel hop has also caused me to almost loose control when sliding sideways, sometimes it grabs sometimes it slides, charictaristics go to shit with that much power. A nice smooth sliding rear tire burn will allow more control. For a $60 addition to the rear it dose wonders for the life of rear drivetrain and suspension. :sorry:
There are better methods than hacking and whacking indiscriminately....ex-Chrysler engineer - 30 years suspension and vehicle Design and development experience inc Jeep/Dodge Motorsports Vehicle Design and Engineering support (if you want to make comparisons-you are going to have to do better than that....LOL)

Best regards....

Bob

ADDENDUM: If you want to see it done right-take a close look how Chrysler designed the rear springs and spring mounting on the 1968 SS/A and SS/AA A-bodies. Those Hemis put out a BIT more horsepower and torque that your little engine. All they used was a pinion snubber and specially designed springs-a LOT cheaper than doing it your way and less chance of breakage of other parts.

[jmm756]

well i will say the spring life will be longer, not shorter with a set of bars. a pinion snubber and different springs will cost ay more than a 40 dollar custom slapper bar build. And yep they do have more power, but currently working on a motor, i would like to see 800 rear wheel out of a 4.7. Now give me arround 17 to 18 mpg and i'll take my little 4.7 and drive it every day.

[Bob Sheaves]

well i will say the spring life will be longer, not shorter with a set of bars. a pinion snubber and different springs will cost ay more than a 40 dollar custom slapper bar build. And yep they do have more power, but currently working on a motor, i would like to see 800 rear wheel out of a 4.7. Now give me arround 17 to 18 mpg and i'll take my little 4.7 and drive it every day.
Do the geometry of the spring-it will fail at the front eye. As an engineering student you have to learn sometime that what you "say" doesnt mean anything in the realm of fact. If you are an engineer and cannot build you own springs, you must be a first year student- all you need is a torch and a single LH spring assembly from a junkyard, a new center bolt and MAYBE a pair of U-bolts. There are about $30.00 in materials (including welding rod or MIG wire for welding the snubber) to modify the springs, build a pinion snubber, and set it up. Like I said-go LOOK at one and LEARN, Luke Skywalker... :)

If you want me to do the work for you it will cost you my normal rate....

Best regards,

Bob

[jmm756]

I just want slapper bars!!

[jmm756]

sorry bob, we will see how my 4x4 works set up like i want. If i ever break the springs i will bow down to you. Though with the bump stop right directly below the front eye of the spring, it will reduce the stress in the spring, by Causing it to wrap up less. And if you can pull a good set of springs from a junk yard for 30 bucks. Wholy s*** send me as many as you can get!!! I never see any sold for under $100

and no third year student. And I have done very well with fabricating and changing my setups on all my vehicals. Slapper bars work very well, without changing the charictaristics of the stock suspension at all. They just minimize the S shape made by the rear springs when under a load. Were not talking about bringing the front end off the ground on a quad cab, i just want to burn rubber without chirp, chirp, chirp. it is excessivley bad on the 4x4 due to spring over.

I don't ever get mad, I just love to argue. Their has to be some reason everyone is running slappers and telling about great results on their dakotas. :banana2:

[Bob Sheaves]

sorry bob, we will see how my 4x4 works set up like i want. If i ever break the springs i will bow down to you. Though with the bump stop right directly below the front eye of the spring, it will reduce the stress in the spring, by Causing it to wrap up less. And if you can pull a good set of springs from a junk yard for 30 bucks. Wholy s*** send me as many as you can get!!! I never see any sold for under $100

and no third year student. And I have done very well with fabricating and changing my setups on all my vehicals. Slapper bars work very well, without changing the charictaristics of the stock suspension at all. They just minimize the S shape made by the rear springs when under a load. Were not talking about bringing the front end off the ground on a quad cab, i just want to burn rubber without chirp, chirp, chirp. it is excessivley bad on the 4x4 due to spring over.

I don't ever get mad, I just love to argue. Their has to be some reason everyone is running slappers and telling about great results on their dakotas. :banana2:
There is...they don't know any better..... it is "follow the Chevy" without understanding why. You still need to run the spring geometry- you are incorrect in your assumptions. The spring does MORE than just turn into the letter "S"-think what happens when you hit a pothole and you compress the spring.

As the spring flattens, It gets longer (or else it would not need a shackle at the rear end to allow the length change as the spring flattens). Now what ELSE happens? the distance from the centerline of the axle to the centerline of the front hanger bolt INCREASES ALSO becasue the axle is rigidly mounted to the spring at a fixed point (that is why a center pin is used). The spring flattens out evenly along it's length, forcing the wheelbase to increase-meaning the rear axle MOVES TO THE REAR of the car.

Now, with what you are proposing to build (and probably will regardless, until you break parts and then blame something else) is a rigid link between the axle centerline and an anvil that hits the front spring eye at the hanger bolt. Now think about what is happening here under motion...the spring compresses under hard accelleration, gets longer, and now, YOUR ANVIL NO LONGER HITS THE EYE_IT HITS BEHIND THE EYE (becasue it stays the same length, wqhile the spring increases length due to the spring flattenning under load), causing the spring to fail in a short order. How many cycles? Good question and with the information given, I dont have an answer. Based on past experience, 50-100 runs was all the Chevy Camaro ProStocks and SS/A cars could live with before a spring failed. On the street-well, this garbage has no business on the street at all for a number of reasons, none of which I care to argue at this time.

As a side note-I pick up broken springs from a junkyard all day long for $10-$12 each pair. I never said you needed to have a good main leaf-I did not, in fact, describe exactly WHAT you needed to get-assuming (incorrectly on my part) that you understood what I was referring to. Since you didn't I will explain. What you want is 1 half leaf from the left spring to be removed (becasue the rate is higher on this particular leaf than the right). To get this, you take the spring, clamp it into 2 C-clamps (kiddies , dont do this at home), torch off the old center bolt and drive it out with a punch. Then, SLOWLY release the clamp pressure of the C-clamps to disassemble the spring. Remove the RH spring from your car and disassemble it. Finally, using the longer center bolt, assemble the old spring with the new half leaf on the bottom, next to the axle spring pad. Tighten to spec and reassemble the truck with the u-bolts. Now test......you may possibly have to add one more half leaf to the pack to stop most of the wrap (the target is 5degrees of axle rotation maximum). The pinion snubber I hope is self explanitory...

Best regards,

Bob

[HemiDak]

Bob,

Would this be any better?

http://mywebpages.comcast.net/charlesrichards/06%20.JPG

[Bob Sheaves]

Yes, for 2 reasons:

1. The spring is an air spring (obviously) and as such, requires restraint in 2 of the 3 axis' of motion to develop a spring rate. The control arms (in black-made of what looks like a single leaf and a gusset bar) provide that restraint. To be certain, I would need to see the shackle end to determine slipper or swing angles.

2. The red anti-wrap bar shown prevents the axle housing from rotating "freely" (as when mounted to a leaf spring) and minimizes the fore and aft travel of the axle due to the long radius beteen the "frame mounted" end pivot and the axle housing rigid mounting.


The catch with this design is that you have to watch the degrees of rotation of the axle (and therefore, the pinion joint) to ensure that you do not make the mistake of exceeding the critical speed of the joint itself for the shaft length in angularity. What this means is there is a critical speed and which the operating angle of the joint will be exceeded by the accelleration and decelleration of the joint as the propshaft rotates.

Best as always,

Bob

ADDENDUM: the low number of leaves in the black spring shown will make the spring action "floppier" (lower spring rate) spreading the loading of the flattenning of the spring as it moves. The "Slapper bar" concentrates this force.

Neither of these two shown alternative is optimum however, as they are still "bandaids" on a system, instead of an actual, designed system to control the forces. Adding weight aint good for anything except lowering the natural frequency of a part....LOL.

[jmm756]

whats wrong with going to a ladder bar system then?
instead of slapper bars

[Bob Sheaves]

whats wrong with going to a ladder bar system then?
instead of slapper bars
The system shown above is a ladder bar system and it is a better choice between the 2 choices of "slapper bar" and "ladder bar", for the reasons stated above. As I said before-neither is optimum for the end result and both add weight-sprung and unsprung. The big advantage of the particular ladderbar system shown is the spring rate adjustability (from the cab if you do it right) of the 2 air springs, allowing you to change the weight bias from side to side easily as track conditions change. This is a downfall also of the half leaf and pinion snubber design as once you assemble the springs-you can only adjust the rate by physically changing the spring pack assembly, unless you play games or have a loose rulebook to follow. You can change the total number of degrees of axle rotation with the snubber design (by raising it or lowering it relative to it's contact point-a crossmember with a pad welded and gussetted to the frame) but not the spring rate (you COULD employ the old circle track/short track method of leaf spring weight jacks, but that would cost more money for little benefit in a straight line) or the RATE of pinion angle change.

Best as always,

Bob

[jmm756]

I'm going to try adding the springs as suggested. All i'm hoping for is to reduce wheel hop. Any other suggestions are appreciated. I may use the snubber if the added leafs don't help to eliminate it. thanks

[Bob Sheaves]

I'm going to try adding the springs as suggested. All i'm hoping for is to reduce wheel hop. Any other suggestions are appreciated. I may use the snubber if the added leafs don't help to eliminate it. thanks
Just remember the half leaf points forward when installed in the vehicle, not towards the rear of the car. Also, don't add more than 2 half leafs on one side-if you still want to increase the force, add ONE to the opposite side. If you still cannot hold the rotation of the axle to 5 degrees or less, add the snubber.

Best as always,

Bob

[jmm756]

i have a plazma cutter and welders, so it shouldn't be that bad. I don't know of anything else i may need, and would it be better to put it through the whole length or just in the front? for the first one and or both if i use two

[Bob Sheaves]

i have a plazma cutter and welders, so it shouldn't be that bad. I don't know of anything else i may need, and would it be better to put it through the whole length or just in the front? for the first one and or both if i use two
In the front only, becasue the addition is to stiffen the spring selectively to increase the effort required to twist the axle (hence, "S" the springs) in relation to traction at the ground contact patch. By only increasing the front, you minimize the effect on a 2 wheel jounce or rebound, thus preserving most of the original ride quality and minimizing harshness. Note that I do NOT mean the truck will ride as smooth as the OE configuration, I mean the truck will ride better when compared to slapper bar (especially) or ladder bars. All added leaves should only face the front.

Best regards....

Bob

[BlackDak]

I feel like an idiot, watching two guys go back and forth over stuff I have NO clue about!

So, what's the verdict? I just removed the front driveshaft from my AWD Dakota, and am getting terrible wheel hop. I'd like to bolt something on to stop this.

Snubber? I had one on my 66 Barracuda that worked wonders, as well as traction bars. Is there a bolt-on snubber for us?

[Anthony]

blackdak,
remember we were talking about spring clamps for lowering?? Well the purpose of them is to reduce wheel hop and at the same time they drop the rearend. Try them out!!

[BlackDak]

I could fab some up, but I'd rather buy them. Are they available commercially?

[Anthony]

check any auto part store, they should have them. BTW let me know how they work and how much drop you get!!

[cloknem]

There is...they don't know any better..... it is "follow the Chevy" without understanding why. You still need to run the spring geometry- you are incorrect in your assumptions. The spring does MORE than just turn into the letter "S"-think what happens when you hit a pothole and you compress the spring.

As the spring flattens, It gets longer (or else it would not need a shackle at the rear end to allow the length change as the spring flattens). Now what ELSE happens? the distance from the centerline of the axle to the centerline of the front hanger bolt INCREASES ALSO becasue the axle is rigidly mounted to the spring at a fixed point (that is why a center pin is used). The spring flattens out evenly along it's length, forcing the wheelbase to increase-meaning the rear axle MOVES TO THE REAR of the car.

Now, with what you are proposing to build (and probably will regardless, until you break parts and then blame something else) is a rigid link between the axle centerline and an anvil that hits the front spring eye at the hanger bolt. Now think about what is happening here under motion...the spring compresses under hard accelleration, gets longer, and now, YOUR ANVIL NO LONGER HITS THE EYE_IT HITS BEHIND THE EYE (becasue it stays the same length, wqhile the spring increases length due to the spring flattenning under load), causing the spring to fail in a short order. How many cycles? Good question and with the information given, I dont have an answer. Based on past experience, 50-100 runs was all the Chevy Camaro ProStocks and SS/A cars could live with before a spring failed. On the street-well, this garbage has no business on the street at all for a number of reasons, none of which I care to argue at this time.

As a side note-I pick up broken springs from a junkyard all day long for $10-$12 each pair. I never said you needed to have a good main leaf-I did not, in fact, describe exactly WHAT you needed to get-assuming (incorrectly on my part) that you understood what I was referring to. Since you didn't I will explain. What you want is 1 half leaf from the left spring to be removed (becasue the rate is higher on this particular leaf than the right). To get this, you take the spring, clamp it into 2 C-clamps (kiddies , dont do this at home), torch off the old center bolt and drive it out with a punch. Then, SLOWLY release the clamp pressure of the C-clamps to disassemble the spring. Remove the RH spring from your car and disassemble it. Finally, using the longer center bolt, assemble the old spring with the new half leaf on the bottom, next to the axle spring pad. Tighten to spec and reassemble the truck with the u-bolts. Now test......you may possibly have to add one more half leaf to the pack to stop most of the wrap (the target is 5degrees of axle rotation maximum). The pinion snubber I hope is self explanitory...

Best regards,

Bob


Brilliant read... :clap2:

thanks!

[96BlkDak]

There is...they don't know any better..... it is "follow the Chevy" without understanding why. You still need to run the spring geometry- you are incorrect in your assumptions. The spring does MORE than just turn into the letter "S"-think what happens when you hit a pothole and you compress the spring.

As the spring flattens, It gets longer (or else it would not need a shackle at the rear end to allow the length change as the spring flattens). Now what ELSE happens? the distance from the centerline of the axle to the centerline of the front hanger bolt INCREASES ALSO becasue the axle is rigidly mounted to the spring at a fixed point (that is why a center pin is used). The spring flattens out evenly along it's length, forcing the wheelbase to increase-meaning the rear axle MOVES TO THE REAR of the car.

Now, with what you are proposing to build (and probably will regardless, until you break parts and then blame something else) is a rigid link between the axle centerline and an anvil that hits the front spring eye at the hanger bolt. Now think about what is happening here under motion...the spring compresses under hard accelleration, gets longer, and now, YOUR ANVIL NO LONGER HITS THE EYE_IT HITS BEHIND THE EYE (becasue it stays the same length, wqhile the spring increases length due to the spring flattenning under load), causing the spring to fail in a short order. How many cycles? Good question and with the information given, I dont have an answer. Based on past experience, 50-100 runs was all the Chevy Camaro ProStocks and SS/A cars could live with before a spring failed. On the street-well, this garbage has no business on the street at all for a number of reasons, none of which I care to argue at this time.

As a side note-I pick up broken springs from a junkyard all day long for $10-$12 each pair. I never said you needed to have a good main leaf-I did not, in fact, describe exactly WHAT you needed to get-assuming (incorrectly on my part) that you understood what I was referring to. Since you didn't I will explain. What you want is 1 half leaf from the left spring to be removed (becasue the rate is higher on this particular leaf than the right). To get this, you take the spring, clamp it into 2 C-clamps (kiddies , dont do this at home), torch off the old center bolt and drive it out with a punch. Then, SLOWLY release the clamp pressure of the C-clamps to disassemble the spring. Remove the RH spring from your car and disassemble it. Finally, using the longer center bolt, assemble the old spring with the new half leaf on the bottom, next to the axle spring pad. Tighten to spec and reassemble the truck with the u-bolts. Now test......you may possibly have to add one more half leaf to the pack to stop most of the wrap (the target is 5degrees of axle rotation maximum). The pinion snubber I hope is self explanitory...

Best regards,

Bob


Very nice write up.

Summit racing has a "generic" set of ladder bars that can be welded in and allow for the axle to be attached but not fixed to the spring pack. There are none on thier site specifically for Dakotas or Durnagos.

[9t9-5.2]

One would be better off going to a four link vs. ladder bars, but they can be costly and you have to add some type of spring, coil overs, air bags, etc.

[Jasoon]

Holy old thread revival, batman!