Triple X'n the D-max

[mrtwstr]

Originally Posted by Grumpy_old_fart

heres a couple of questions...

are the s hackles on each end of the spring in tension or in compression?

Now you're just throwing around big words tryn to sound smart.
Sorry man, I just realized I don't have the Shackles in the drawing so you're asking if they're mounted up or down.
They will be mounted up, in compression.

Originally Posted by Grumpy_old_fart

if the leaf springs are only used to suspend the vehicle, why not make it a 1/4 elliptic setup? too funky for ya? why not have a 1/2 spring on each side holding the truck up instead of a whole one? it would weigh less. do it right, and you could adjust the ride height, too.

Lighter? Really? I think maybe you're missing something.
You do realize that you don't just run 1/2 a leaf spring right? If you did, that would be half the spring rate. Right? So, a 1/4 elliptic spring with the same spring rate would need to be twice as many leafs. So... in fact the spring it's self would end up heavier! Plus you gotta mount it and all that junk.
It could be kewl, but not lighter!

"Too funky for me" ? I'm not even gonna respond to that one.

Originally Posted by Grumpy_old_fart

all the old style buggies and wagons used leaf springs... we are only 150 years into using suspension... why not use what we used 150 years ago... if it still works, keep using it.

Now that's just a lame attempt at being a smart ass. You're just tryn to argue.
I'm pretty sure, correct me if I'm wrong, all the way through 2011 EVERY manufacturer of pick up trucks still uses Leafs in the rear. I wonder why?

The only trucks I've ever heard of running Coils in the rear are the older Chevy 1/2 ton trucks we talked about earlier and the 2009 Ram 1500.
Important note.. Those are both 1/2 ton trucks, and they both have about 8", maybe 10" of travel at most.

Here's an interesting little write up I found...
In 1967, GM used a 3 link (as opposed to the new Ram's 5 link) coil sprung suspension. The result was that the vehicle had a very comfortable ride when empty (industry leading, in fact), but when any load was placed in the pickup bed, the vehicle became unstable and sloppy handling. This result almost sank the new trucks before they were even out of the gate (it was deleted in favor of a conventional Hotchkiss shortly thereafter). The new Ram is the first U.S. volume built pickup truck since that time to attempt to use coil springs as its primary suspension system.

[mrtwstr]

Originally Posted by BRORSAM

MRTWSTR:

Yes, I ran airbags all around on my truck. Yes, I'm converting to coilovers strictly in the name of wheel travel. Would I say that airbags suck? Certainly not. Matter of fact, their greatest virtue may be their progressive nature---the very same quality you are touting from the leaf springs.

For the record, I ran the same set of airbags (yes, semi truck airbags) from 1995 to 2007 with ZERO failures, and at the time they were removed from service they are still more than capable of further use. Yes I was limited to about 12 inches of usable wheel travel, but for MY application and MY usage, they turned out to be an excellent choice.

Maintenance? Occasionally checking pressure and re-confirming ride height, but nothing other than that.

Airbags can rival leaf springs in terms of overall load capacity, are MUCH lighter, really not all that expensive, and are surprisingly tolerant of angular displacement.

Airbags = lame? What in the world is lame about any setup that works well for its intended use?

Now...would I claim my airbag setup to be the solution to everyone's problems? Absolutely not. They were my solution when I got tired of screwing around with leaf springs. And yes...in a previous revision (1991, if I recall) I ran double-shackled leaf springs with a 3 link---so yes, I have experience there as well. (I thought the leaf springs sucked because they were so heavy, and had such a stiff initial spring rate.)

So, let's be fair here---air bags are every bit a viable option as any other spring type. It all comes down to the particulars of the application and personal preference.

I hope I don't sound like a Dick when you guys read my posts. I'm not tryn to sound like a know-it-all or something like that.
I try to type my responses like we're all a bunch of friends sitting around a camp fire talkin smack about each others rigs. So, please take my responses with a grain of salt.


That's kewl you've had success with them. That's a hell of a LOT longer service life than I've ever experienced or heard from anyone running them. But.... I'm guessing you just had the bags? No On Board Air system with valves, incab controls, sensors or nothing like that. Right? Just the bags?

[CumminsK30]

Airbags do have their place in the suspension world, but hardcore offroad is usually not that place. For a truck that primarily tows they can't be beat. The biggest problem with air suspension for offroad rigs is not in the bags themselves, but in the air management and controls. Compressors, valves, lines, fittings, switches, etc each add another possible point for failure and are usually where the problems occur.

Airbags do have some benefits that neither coil springs nor leaf springs can provide. They have a progressive spring rate by design (as the air chamber compresses the spring rate increases) and the spring rate is easliy and quickly changed by simply changing the air pressure in the bag. They offer a smoother ride than leaves when the truck is empty, and if set up correctly will handle more weight with greater stability than leaf springs can while still maintaining the truck's proper ride height. Another interesting point is that they act as huge rubber isolators and transmit less road noise and vibrations into the cab of the truck - not important for hardcore wheelers but it is nice for multi purpose dd trucks like this.

[SmokinDuradog]

Worked on some little things while I patiently wait for Ballistic to make my parts that were ordered and paid for in Jan. Front diff cover is painted up and bolted on. Hardware and brackets for the Road armor front bumper are all ready to hang the bumper back on. Solved the issue with not knowing exactly how to mount my remote res for my Racerunner coilovers. Here's a pic of what I did. Just welded a 1" sch 40 black pipe to the bracket that was supplied by Toby. I am going to put a 45* elbow on the coilover then loop the hose to back of the wheel well and then mount the res horizontal in the wheel well. I plan to just use the rubber isolator mounts with the stainless hose clamps to attach the Res to the pipe.

[Grumpy_old_fart]

Originally Posted by mrtwstr

Now you're just throwing around big words tryn to sound smart.
Sorry man, I just realized I don't have the Shackles in the drawing so you're asking if they're mounted up or down.
They will be mounted up, in compression.



Lighter? Really? I think maybe you're missing something.
You do realize that you don't just run 1/2 a leaf spring right? If you did, that would be half the spring rate. Right? So, a 1/4 elliptic spring with the same spring rate would need to be twice as many leafs. So... in fact the spring it's self would end up heavier! Plus you gotta mount it and all that junk.
It could be kewl, but not lighter!

"Too funky for me" ? I'm not even gonna respond to that one.




Now that's just a lame attempt at being a smart ass. You're just tryn to argue.
I'm pretty sure, correct me if I'm wrong, all the way through 2011 EVERY manufacturer of pick up trucks still uses Leafs in the rear. I wonder why?

The only trucks I've ever heard of running Coils in the rear are the older Chevy 1/2 ton trucks we talked about earlier and the 2009 Ram 1500.
Important note.. Those are both 1/2 ton trucks, and they both have about 8", maybe 10" of travel at most.

Here's an interesting little write up I found...
In 1967, GM used a 3 link (as opposed to the new Ram's 5 link) coil sprung suspension. The result was that the vehicle had a very comfortable ride when empty (industry leading, in fact), but when any load was placed in the pickup bed, the vehicle became unstable and sloppy handling. This result almost sank the new trucks before they were even out of the gate (it was deleted in favor of a conventional Hotchkiss shortly thereafter). The new Ram is the first U.S. volume built pickup truck since that time to attempt to use coil springs as its primary suspension system.

ok.... so... based spring rate calculations *(Triaged has one on here somewhere....) you can make a 36 inch long spring with 6 leaves stiffer than a 63 inch long spring with 6 leaves. Im thinking that will cut some weight down. Depending on how you mount your spring to axle setup, you can make that adjustable for ride height as well.



Of course, youre the major fabricator here. I thought you would be able to do those things. Less weight, easier to package, less mounting issue at the axle, adjustability. oh... and innovative.


as for the write up you found, think of it a little differently.
GM started using trailing arm rear suspension in 1960 in pickups. Yes, 1960. Trailing arm rear suspension was used in Chevy and GMC trucks through 1972. thats only 12 years of use. The design did not lend itself well to owner adjustments. panhard bar mounts wore out. there was more problem with a poorly designed shock layout and coil spring layout than anything else. GM remedied the issue with heavy loads, too. they used a 1/4 elliptic overload spring that was mounted to the frame BEHIND the rear end and pointed forward to contact the axle only when a generous load was placed in the rear of the truck.

this suspension design was only used on 2wd trucks and suburbans of that era. It was not a failure. it was something that worked. to make all assembly lines use common parts, the trailing arm was switched back to leaf springs for both 2 and 4wd trucks and from 1973 on, 2wd and 4wd trucks used the same rear spring mounts and springs, per weight rating.

Using big words? We havent even gotten there yet. as for me just trying to argue, i tend to know my subjects enough to be able to argue them reasonably well.

Why mount the shackle in compression? trying to gain lift? a shackle mounted in tension will allow for more freedom of movement, less bind, and the springs will work against the shackle less.

I will attach a pic of a spreadsheet to help you understand the reasoning about the shorter, 1/4 elliptic springs..

[BRORSAM]

Originally Posted by mrtwstr

I hope I don't sound like a Dick when you guys read my posts. I'm not tryn to sound like a know-it-all or something like that.
I try to type my responses like we're all a bunch of friends sitting around a camp fire talkin smack about each others rigs. So, please take my responses with a grain of salt.


That's kewl you've had success with them. That's a hell of a LOT longer service life than I've ever experienced or heard from anyone running them. But.... I'm guessing you just had the bags? No On Board Air system with valves, incab controls, sensors or nothing like that. Right? Just the bags?

No worries, bud---I didn't take any offense. I actually find it refreshing to have these discussions with someone who has an opinion (even if it's different than mine) and is capable of thinking rationally on such subjects.

As for my truck, it was airbags in the rear, isolated from each other---no plumbing connecting them. I'd check ride height about once a month while I was checking tire pressures. Up front I had a homemade manifold (crude, but it worked...) with a ball valve and individual dump valves and fill valves for each side. Normally I'd run with the ball valve closed for more roll resistance, or I could open it to link both fronts whenever I wanted the most flex possible. I could dump either side independently of the other (for off camber siuations), or even dump one side and fill the other. Plenty of options available with pretty simple (and admittedly crude) plumbing parts. No self-leveling controls or sensors---just onboard air from the ARB compressor.

How about I make you a deal? If I ever get my ticket punched for Top Truck, we sit down around a campfire and have that talk....

[mrtwstr]

Originally Posted by Grumpy_old_fart

ok.... so... based spring rate calculations *(Triaged has one on here somewhere....) you can make a 36 inch long spring with 6 leaves stiffer than a 63 inch long spring with 6 leaves. Im thinking that will cut some weight down. Depending on how you mount your spring to axle setup, you can make that adjustable for ride height as well.



Of course, youre the major fabricator here. I thought you would be able to do those things. Less weight, easier to package, less mounting issue at the axle, adjustability. oh... and innovative.


as for the write up you found, think of it a little differently.
GM started using trailing arm rear suspension in 1960 in pickups. Yes, 1960. Trailing arm rear suspension was used in Chevy and GMC trucks through 1972. thats only 12 years of use. The design did not lend itself well to owner adjustments. panhard bar mounts wore out. there was more problem with a poorly designed shock layout and coil spring layout than anything else. GM remedied the issue with heavy loads, too. they used a 1/4 elliptic overload spring that was mounted to the frame BEHIND the rear end and pointed forward to contact the axle only when a generous load was placed in the rear of the truck.

this suspension design was only used on 2wd trucks and suburbans of that era. It was not a failure. it was something that worked. to make all assembly lines use common parts, the trailing arm was switched back to leaf springs for both 2 and 4wd trucks and from 1973 on, 2wd and 4wd trucks used the same rear spring mounts and springs, per weight rating.

Using big words? We havent even gotten there yet. as for me just trying to argue, i tend to know my subjects enough to be able to argue them reasonably well.

Why mount the shackle in compression? trying to gain lift? a shackle mounted in tension will allow for more freedom of movement, less bind, and the springs will work against the shackle less.

I will attach a pic of a spreadsheet to help you understand the reasoning about the shorter, 1/4 elliptic springs..

you can make a 36 inch long spring with 6 leaves stiffer than a 63 inch long spring with 6 leaves.
No shit genius. BUT... In order to do so they need to be THICKER, so therefore they would be heavier!
PLUS.... we don't want a "stiff" spring.
We want the smoothe yet agresive progressive rate that you can only get with long multi leaf packs. You just simply can not get that out of short fat springs.
Now you're arguing my point for me.
We're not just going for a stiff spring. We want a smoothe ride, flexability and Load Capability. The longer the Leaf is the better it can do all those things.
No doubt it could be done with a 1/4 elliptic spring, but it would not be lighter! No fawkn way!

I will attach a pic of a spreadsheet to help you understand the reasoning about the shorter, 1/4 elliptic springs..
At the risk of sounding arrogant, do you really think you need to explain springs to me?
If you think you're idea would be better suited for his needs that's just fine with me. Fawkn build it or shut the fuck up!
You feel the need to come in here because you got a fawkn black text hard on in another thread and educate me about springs. I've been in this game for a long time dood!

You'd probly argue with a guy about him painting his rig blue because you think your favorite color would look better on his rig. Fawkn let it go!

[JOHNNYWEB]

Originally Posted by Grumpy_old_fart

ok.... so... based spring rate calculations *(Triaged has one on here somewhere....) you can make a 36 inch long spring with 6 leaves stiffer than a 63 inch long spring with 6 leaves. Im thinking that will cut some weight down. Depending on how you mount your spring to axle setup, you can make that adjustable for ride height as well.



Of course, youre the major fabricator here. I thought you would be able to do those things. Less weight, easier to package, less mounting issue at the axle, adjustability. oh... and innovative.


as for the write up you found, think of it a little differently.
GM started using trailing arm rear suspension in 1960 in pickups. Yes, 1960. Trailing arm rear suspension was used in Chevy and GMC trucks through 1972. thats only 12 years of use. The design did not lend itself well to owner adjustments. panhard bar mounts wore out. there was more problem with a poorly designed shock layout and coil spring layout than anything else. GM remedied the issue with heavy loads, too. they used a 1/4 elliptic overload spring that was mounted to the frame BEHIND the rear end and pointed forward to contact the axle only when a generous load was placed in the rear of the truck.

this suspension design was only used on 2wd trucks and suburbans of that era. It was not a failure. it was something that worked. to make all assembly lines use common parts, the trailing arm was switched back to leaf springs for both 2 and 4wd trucks and from 1973 on, 2wd and 4wd trucks used the same rear spring mounts and springs, per weight rating.

Using big words? We havent even gotten there yet. as for me just trying to argue, i tend to know my subjects enough to be able to argue them reasonably well.

Why mount the shackle in compression? trying to gain lift? a shackle mounted in tension will allow for more freedom of movement, less bind, and the springs will work against the shackle less.

I will attach a pic of a spreadsheet to help you understand the reasoning about the shorter, 1/4 elliptic springs..

Of course a shorter leaf spring will be stiffer. That is a leaf spring that is conventionally mounted at both ends. Cut it in half and hang the weight on the end and, well it is going to take a lot more leaves. I have seen a few 1/4 elliptic spring setup's and they always have a hell of a fat spring stack. Especially to provide for towing chores.

Weight between the two set up's would be like splitting hairs, not really worth talking about.This isn't a race car. Its a one ton pickup for crying out loud. Better unpack that cooler of beer, may weigh you down. No wait, on second thought, bring more beer.

Not to mention that there will be a lot more fabrication with anything more than what Toby is talking about. I have seen it in person at his shop. Change one spring hanger on the frame bolt up the shackles and springs and away you go!!

Tension vs. Compression shackle is always debated. For this application 10-12" of lift it is the way to go unless you lower the spring hangers off the side of the frame. Gay IMO. So back to making it a clean and easy setup.. compression shackles it is. For the record, I run all my trucks tension shackle but my trucks are low to the ground with lots of fender massaging for tire clearance.

I find it Interesting that you are trying to argue and defend something oem manufacturers abandoned years ago!! Oh except Dodge on their new 1500??, Not even close to what we are talking about. Who buys Dodges anyway?? hahaha lol

"as for me just trying to argue, i tend to know my subjects enough to be able to argue them reasonably well." Really? You can argue all you want, I dont see 1/4 elliptic spring set up's coming back anytime soon. Back to why Toby is the "Major Fabricator" and to our original post about the Duramax build...........

[Grumpy_old_fart]

Originally Posted by mrtwstr

If you think you're idea would be better suited for his needs that's just fine with me. Fawkn build it or shut the fuck up!
You feel the need to come in here because you got a fawkn black text hard on in another thread and educate me about springs. I've been in this game for a long time dood!

You'd probly argue with a guy about him painting his rig blue because you think your favorite color would look better on his rig. Fawkn let it go!

yup, yer the expert... People pay you thousands of dollars to get your name on their shit. thats neat.

I honestly dont give a fawk about what color his vehicle is. youre the guy pointing out something someone else wrote that was flawed in its basics, and the years werent even correct but youre using that information to base a decision off of?...

What is being posted here are opinions. if you dont like mine, fine. I dont like yours. I think vendors need to post in the vendor forum, or buy a star. have someone pimp your shit there.

Sure, you have many miles of coverage in magazines. good for you. you deserve some credit. Im sure some of these guys will give you some.

the only real reason I posted anything was to make you see that there are more than one option out there. Someone else did the same thing, and when he returned fire at you, you managed to shut the fuck up long enough to listen...

Sounding arrogant? Its a little late for that.

[Elvis38]

Originally Posted by Grumpy_old_fart

yup, yer the expert... People pay you thousands of dollars to get your name on their shit. thats neat.

I honestly dont give a fawk about what color his vehicle is. youre the guy pointing out something someone else wrote that was flawed in its basics, and the years werent even correct but youre using that information to base a decision off of?...

What is being posted here are opinions. if you dont like mine, fine. I dont like yours. I think vendors need to post in the vendor forum, or buy a star. have someone pimp your shit there.

Sure, you have many miles of coverage in magazines. good for you. you deserve some credit. Im sure some of these guys will give you some.

the only real reason I posted anything was to make you see that there are more than one option out there. Someone else did the same thing, and when he returned fire at you, you managed to shut the fuck up long enough to listen...

Sounding arrogant? Its a little late for that.

Kettle and pot what color are they.

[mrtwstr]

Originally Posted by BRORSAM

How about I make you a deal? If I ever get my ticket punched for Top Truck, we sit down around a campfire and have that talk....

That would be awesome! Shoot me a PM if you want to come watch this year.

[mrtwstr]

Originally Posted by Grumpy_old_fart

the only real reason I posted anything was to make you see that there are more than one option out there.

Grumpy... I know I shouldn't drag this out any longer, but I can't help but respond to this.
I also know this might make me sound a little more arrogant but I really don't care.

Seriously dood.... Do you really think I don't know about the other options out there? Do you really think I haven't weighed the pro's and con's of all the other systems out there? You think I just got the idea of this set up and started spewing out how it's the only way to go? You think I need you to "enlighten" me about 4wd suspension systems like I have built professionally for about 25 years?
You mentioned 1/4 Elliptic. I've built them!
You mentioned cantilever. I've built them!
Coil Overs were talked about. I've built HUNDREDS of them!
Air Bags were mentioned. I've built them!
This is what I do every single day!

If you had some ideas of what might be better suited for Cory's rig you coulda threw them out there as suggestions, without personal snide comments and that would have been kewl. That's not what you did!

[Grumpy_old_fart]

Toby, go back and read my posts. I dont sound any more arrogant than you do.

both of us can continue, its a wash.


When I asked a question, you basically tried to call me a dumbass, and one of your cronies decided to follow suit.

When you posted a clip, i hopped on board about accuracy, which wasnt completely against you, but shows that any viewpoint can be skewed if the facts are slightly out of line, as long as there is something to pick at.

We dont need to argue any points here. nobody will win. I asked a question about compression or tension in shackle design, trying to understand the idea, and put out my opinion. I prefer tension, i think you would too, if you could package it.

as with any suspension package, its just that. a package. making it fit isnt as easy as making it work. making it work is more important.

Neither of us will argue that. Neither of us will give in, either.

Do what you do. dont worry about those of us that disagree, everyone needs a critic. Elvis is my own personal critic... Im used to it.

[jolane]

Interesting read. I've never personally used airbags, but am considering them on my build for capacity (combined with the current leaves). I don't need 12" of travel, and feel that the Carli long travels would work well for my app. I will have OBA already, and the plumbing issues are solvable. After all, brakes systems are just components connected with plumbing (that operate under much higher pressures). I prefer to hardline were I can, and use AN's if possible.

A few questions come to mind.
1. How much travel is realistic out of leaf springs? At 63" long, what would be considered 'safe', in terms of not killing the springs from too much travel?

2. If they do travel 12", are they still adequate for hauling/towing (load capacity)?

I'm very interested to see the final results. This includes load capacity, travel, etc.

[MNtal]

Never thought of the progressive nature of the spring, not fully convinced but am curiouse to see this thing work...

[JOHNNYWEB]

Originally Posted by jolane

Interesting read. I've never personally used airbags, but am considering them on my build for capacity (combined with the current leaves). I don't need 12" of travel, and feel that the Carli long travels would work well for my app. I will have OBA already, and the plumbing issues are solvable. After all, brakes systems are just components connected with plumbing (that operate under much higher pressures). I prefer to hardline were I can, and use AN's if possible.

A few questions come to mind.
1. How much travel is realistic out of leaf springs? At 63" long, what would be considered 'safe', in terms of not killing the springs from too much travel?

2. If they do travel 12", are they still adequate for hauling/towing (load capacity)?

I'm very interested to see the final results. This includes load capacity, travel, etc.

Leaf springs will and do travel 16-20" with out much effort on many setups. Especially with a 63" spring. The thing that kills leaf springs is negative arch. I have been told 2.5" is max you want to see.

Does this Duramax need that much travel? I am thinking 14-15" would do just fine. IMO

[jolane]

Originally Posted by JOHNNYWEB

Leaf springs will and do travel 16-20" with out much effort on many setups. Especially with a 63" spring. The thing that kills leaf springs is negative arch. I have been told 2.5" is max you want to see.

Does this Duramax need that much travel? I am thinking 14-15" would do just fine. IMO

16-20"? Wow. So, if I subtract the 2 1/2" (assume you mean that it can travel this far in negative arch), you get 13 1/2 - 17 1/2" of travel. Does this mean that your free arch must be close to these numbers? Does this include some travel from the shackles? Personally, my vehicles don't sit high enough for spring free-arches in that range.

[mrtwstr]

The amount of droop you can get from a long, thin, milti-leaf pack is impressive and wont hurt the spring at all. And, at the same time, you still have an agressive progression from ride height due to the nature of Leafs that allows great load capacity too.

Keep in mind, we're not talking about stock springs. Stock springs are not a bad option, but they do not have all the benifits/features of quality aftermarket milti leaf packs like Deavers.

Like Johnny said, over compressing them is what kills them. ####EDIT#### AND, the thing that kills most Leafs IMO is that they have the stress of locating the axle also! ####EDIT,EDIT#### AND the stress or trying to control axle wrap. So, this 4 link w/Leafs...

Johnny's Blazer is on the cover of Four Wheeler this month. Ironic isn't it Grumpy. It's been a couple years since we built it, IIRC we put 16" shocks on it and it uses every inch. It's been wheeled hard for years.

Does this mean that your free arch must be close to these numbers? Does this include some travel from the shackles? Personally, my vehicles don't sit high enough for spring free-arches in that range.

Free Arch isn't really what matters. It's compression from Ride Height arch to flat that really matters.
Just to throw out an imaginary ideal situation... You'd want a spring that has say a 5" arch from ride height to flat, then stop it durring compression an inch shy. You could easily run a 16" shock with 4" uptravel and 12" droop. Good quality 63" Leafs will have that much travel easily and the spring will last.

[jolane]

Originally Posted by mrtwstr

The amount of droop you can get from a long, thin, milti-leaf pack is impressive and wont hurt the spring at all. And, at the same time, you still have an agressive progression from ride height due to the nature of Leafs that allows great load capacity too.

Keep in mind, we're not talking about stock springs. Stock springs are not a bad option, but they do not have all the benifits/features of quality aftermarket milti leaf packs like Deavers.

Like Johnny said, over compressing them is what kills them. ####EDIT#### AND, the thing that kills most Leafs IMO is that they have the stress of locating the axle also! ####EDIT,EDIT#### AND the stress or trying to control axle wrap. So, this 4 link w/Leafs...

Johnny's Blazer is on the cover of Four Wheeler this month. Ironic isn't it Grumpy. It's been a couple years since we built it but IIRC we put 16" shocks on it and it uses every inch. It's been wheeled hard for years.


Free Arch isn't really what matters. It's compression from Ride Height arch to flat that really matters.
Just to throw out an imaginary ideal situation... You'd want a spring that has say a 5" arch from ride height to flat, then stop it durring compression an inch shy. You could easily run a 16" shock with 4" uptravel and 12" droop and the spring will last.

Thanks Toby! The 4" uptravel makes sense in your imaginary scenario. 12" droop? I guess when the spring doesn't have to control axle wrap, or axle location, they're more flexible in droop. Makes more sense now.

[Grumpy_old_fart]

Originally Posted by mrtwstr;

Like Johnny said, over compressing them is what kills them. ####EDIT#### AND, the thing that kills most Leafs IMO is that they have the stress of locating the axle also! ####EDIT,EDIT#### AND the stress or trying to control axle wrap. So, this 4 link w/Leafs...

Ironic isn't it Grumpy.

not ironic to me.... Nothing wrong with that.

and if you ever want a picture of what axle wrap does to leaf springs, i can show you the springs on my dually. they look suspiciously like a w and an S...

i happen to agree with every bit of what you just posted... People dont believe it until they see it.

[rokcrawlr1]

Air bags need constant maintenance? I guess that's why million mile tractor trailers don't use them anymore. The bracketry you have built is top notch. I admire a lot of the work you have put into his truck and in the end it's his truck and his decision, but saying they are a poor choice for an " all around rig " is a pretty LAME thing to say.


My uncle ( with too much money ) purchased a Kelderman air ride for his all around rig. My father and I installed it for him and I must say the ride quality and versatility of the truck is ridiculously cool!

[BRORSAM]

In most leaf spring applications, it's the springs themselves that locate the axle laterally, and no other means of lateral axle location is required.

(Yes, I am aware that Jeep YJ's use leaf springs and panhard rods, but I suspect that's the exception rather than the rule...)

Anyway, a triangulated 4 link is more than capable of laterally locating the axle on its own. Not disputing that at all.

Question is, if you have a triangulated 4 link AND leaf springs, is the rear axle in effect over-constrained? Or, in other words, will the 4 links fight against the leaf springs (or vice-versa) as the axle is articulated?

If articulation is kept to a minimum, or the leaf springs are "soft" laterally, or if the leaf springs are floated on some sort of pivot assembly on top the axle housing, then this probably isn't an issue.

Do I have a valid concern here, or am I just being paranoid?

[farroffroad]

can't wait to see this done!! I have a small independent auto dealership and I specialize in these duramax diesels... It would be real cool to have a pic of this truck in my show room!

[SmokinDuradog]

I will send you a pic of the truck when its done for your showroom if you really want one... BUT only if you can get me a great deal on a Crew Cab Top Kick or Kodiak 4500 with the 6.6L Duramax. My next Dmax will have a straight axle from the factory Im not going through all this again! LOL! I want to shorten the frame and put a dully bed on it. So if it doesn't have any type of bed that would be even better

[jolane]

Originally Posted by BRORSAM

In most leaf spring applications, it's the springs themselves that locate the axle laterally, and no other means of lateral axle location is required.

(Yes, I am aware that Jeep YJ's use leaf springs and panhard rods, but I suspect that's the exception rather than the rule...)

Anyway, a triangulated 4 link is more than capable of laterally locating the axle on its own. Not disputing that at all.

Question is, if you have a triangulated 4 link AND leaf springs, is the rear axle in effect over-constrained? Or, in other words, will the 4 links fight against the leaf springs (or vice-versa) as the axle is articulated?

If articulation is kept to a minimum, or the leaf springs are "soft" laterally, or if the leaf springs are floated on some sort of pivot assembly on top the axle housing, then this probably isn't an issue.

Do I have a valid concern here, or am I just being paranoid?

In a normal leaf spring set-up, yes, it's overconstrained. I believe what they're doing is adding shackles to the front of the leaf springs also, so now there's two shackles per spring (1 front, 1 rear). This unconstrains the leaf spring to a large degree (could still argue they're constrained laterally a bit).