Long Travel BS Thread

Sounds like a Saturday worth of work.

 

The most important part of all of that will be designing everything to have the proper geometry(anti squat, ic, ect.)

I'd recommend buying a set of weld it yourself links from Trac performance. His are fairly low profile,strong, cnc bent, astectically pleasing, and affordable.

 

Lol yeah I need to revive our PM...

Yeah... I think that shouldn't be too bad. I mean as far as axle positioning goes...

Yeah I'm not sure whether or not to go with a vendor here or try to just build off of ruffstuff...
http://www.ruffstuffspecialties.com/catalog/3LINKKT.html
http://www.ruffstuffspecialties.com/catalog/R1760.html
http://www.ruffstuffspecialties.com/catalog/R1982.html

They degree angle stuff does confuse me...

 

should make a list of what do you want your truck to do. im doing a short coarse 4 link on mine. i would do trailing arms but thats more $$$ just for trailing arms and work to cut stuff out to get the shocks close to the cab than what i wanna do to it. i can still pull a clean 18" of travel with a 18" coil/bypass. more then enough for me and what i wanna do with the truck. i dont want spring under so this is the next best thing but not as pricey as full blown links and still better control then leafs. but each to their own, your truck so do what you wanna do with it and can afford to do

 

RuffStuff uses a bushing in the link where it mounts to your frame. You can angle it if you need to have your links kick out to the outside of your axle. Guys on here like using uniball instead so you can be a bit more relaxed when welding frame mounts.

 

You don't want a bushing on your links. It will apply pretty heavy twisting forces to your frame. @nfs257 used the ruff stuff links on his build, they just swapped out the bushing cups for uniball cups. No extra work needed.

I designed my whole set up prior to purchasing anything. I'd read everything you can on linked suspension geometry long travel and race car related. Coming up with perfect geometry on paper is easy, but when working around stock frames and factory stuff their will be comprimises. The better you understand the ways geometry affects your handling characteristics, the better you can decide how to compromise your ideal design to fit your packaging needs

 

I'd also recommend wobble stoppers with the uniballs

 

Just started my ford 9" build/parts gathering lol, ruffstuff bare housing....CHECK!, friend at Fearless gear building me a third, 35 spline with a Detroit and I'm broke for now haha

 

Just throwing these out here.

Glassworks short bed flat tops. Originally got them from @DTFtacoma 2-3 years ago in a package deal. Friend never mounted them and sold truck.

$250

 

more updates!! @DTFtacoma is killin it! these pictures just make me so excited lol

 

my update isn't nearly as cool.

 

Are you going to be back in az anytime soon?

 

Yes but they sold today.

 

I was under the impression that a 4 link isn't ideal because the gas tank gets in the way... Unless you're talking about super short uppers like in the rear of a JK?

Gotcha.

Gotcha. Uniballs always seem better...

Ok so this is what I don't get. What do you mean come up with a perfect geometry on paper? I don't really understand what you could do different.

The trailing arms/lower links just fall where they fall. I was thinking I would tack them in place with the leafs in place if they don't get in the way. They just hold the axle the proper difference from t-case so the driveline is happy, correct?

Then with the upper link I just need to place it where it twists the axle to the same angle to the driveshaft as the angle coming off the t-case, correct?

Then I mount the pan hard so the axle stays centered.

Cycle, make sure the driveshaft isn't going to fuck the t-case, Make sure all the joints are happy, and then bam figure out what size coils I need.

Wobble stoppers?

 

no. no, no, no, no no no no, no.

you need to factor in anti-squat, roll center/center of gravity, the angle of the lower link/links in relation to the lowers, length of your links too. there's a lot more math to it than just buying parts and slapping them together.

 

Well yeah I'm just doing a cliff notes here but... you're right I haven't done enough research on some things

I thought your coilover spring rates and lengths play a big part in some of those issues...

 

I was under the impression that a 4 link isn't ideal because the gas tank gets in the way... Unless you're talking about super short uppers like in the rear of a JK?

impossible to 4 link with the stock gas tank in place

Gotcha.

Gotcha. Uniballs always seem better...

Ok so this is what I don't get. What do you mean come up with a perfect geometry on paper? I don't really understand what you could do different.

the position and length of every link and mounting point makes a huge difference

The trailing arms/lower links just fall where they fall. I was thinking I would tack them in place with the leafs in place if they don't get in the way. They just hold the axle the proper difference from t-case so the driveline is happy, correct?

no, they don't just fall where they fall. if you are using prefab links you really need to plan and cycle the rear end without your leafs to assess driveshaft plunge. the position on the front mounting point of the link matters and the oisition of the tabs at the axle matter a lot too and impact tge location of your 3rd on the axle as well


Then with the upper link I just need to place it where it twists the axle to the same angle to the driveshaft as the angle coming off the t-case, correct?

no, the length and the mounting points of the 3rd need to be within a very specific range for it to work properly

Then I mount the pan hard so the axle stays centered.

no, with a 3 link the axle is only centered at ride height and again the placement of the mounting points and length of the pan hard matter a lot



Cycle, make sure the driveshaft isn't going to fuck the t-case, Make sure all the joints are happy, and then bam figure out what size coils I need.

Wobble stoppers?
google it, if you use uniballs up front you need them

I would highly suggest you do some research online first because the placement of every mount, every set of tabs and every link is critical. There is a ton of 3 link design info online and even some great calculators to help you with it. If you do it wrong you can get very adverse suspension reactions, it can squat horribly under accelleration, lift on accellerstion, your axle can move excessively laterally, your driveshaft can self destruct, your pinion angle can be horrible etc etc etc

 

Ok I'm going to google for a bit before I embarrass myself more...

 

This is 100% correct. I'd start doing some research on rear linked suspension. Otherwise you'll end up with a truck that performs far worse than a leaf spring truck. It all starts on a piece of graph paper. Once that's under control then you can move onto the real world. That's where it gets fun.

If I were you I'd start by reading chassis engineering by herb Adams. It's not directed towards long travel, but all the principles are the same. Then you can supliment that reading with the small amounts of written knowledge on the inter webs regarding long travel link geometry. But definetly start with the chassis engineering book. Most articles reference it.

You will also want to incorporate a rear sway bar into your design. It will be tight, but don't make the mistake of designing a rear setup that won't allow use of a rear sway bar. You can thank me after you test drive your truck without it.