Link size/joint questions 4 link (1 Viewer)

[FJBen]

The desinging begins...I'm gathering all the parts for a triangulated 4 link on the rear of my 40. I've been doing research til I'm blue at this point...but I've seen A LOT of differing opinions on link size.

I'm going to be running JJ's on one end.

Looking at making the links out of 2" .250 wall DOM...

then sleeving the lowers with maybe some SCH40 to help with strength.

Anythoughts or different ideas that you'd use?

 

[LC_Hamma]

Gonna run coils, coilovers or qtr. ellip.? From my basic research, I found .385 wall DOM lowers, J Joints at the frame & 3/4" cromo rod ends at the axle were the *norm & that's what I use on my 40. Uppers can be 1/4" wall DOM & same joint locations. Coilovers wil be the easiest to mount, but most expensive. Coils take a little more work & qtr. ellip. *seems to be the most time consuming & heaviest option. Get that buildup thread started dude!

then sleeving the lowers with maybe some SCH40 to help with strength.

You gonna cut a groove in your DOM cuz that poop pipe has a raised welded seam on the inside? Just go w/ a DOM outer sleeve, that's what I did.

 

[zornff]

Hey Ben, Talk to Jeremiah (proffitt). I'm running his stuff with 1/4 elipse and they work like a banshee w/105 wb. Mike

 

[Eskimo]

The link size should serve you well.. It won't be indestructable, but should handle some hits pretty well. Diameter is alot more important than thickness to a point, but running links much bigger than 2" becomes a packaging problem!

The uppers don't need to be nearly that large.. 1.5" .120 DOM is actually plenty, but 1.5" .250 would help me feel better, and lets you burn in the ends with more heat..

If you reallly don't want the lowers to bend, the 2" but in a 3/8 or 1/2" thickness will add more strength.. and in the 1/2" wall, you can have the link tapped for the 1.25" shank forged JJ, just like you could with a 1.5" .250 upper

 

[Marko]

We run the high quaility 5/8x 3/4 hiems all around, static rated to 40,685 lbs. If you got your angles and links set-up right then they won't develope slop for a long time.

Lowers 1.75"-2.00" 7075 Alum. Reflex, and strong.

Uppers and panhards. .095 or .120 4130n.

Uppers and panhards should never fail unless some the isn't set-up properly or major failure else where in the suspension.

-John

 

[Marko]

Another option is fabricated plate lowers, designed for the rigs' purpose, properly built they are very strong. This takes quite a bit of time though.....

 

[FJBen]

I plan on running a dual triangulated 4 link and running coils. Prolly running the lower 36" long and the uppers close to 30" hoping. I"m going to try using TJ coils cause I can get those for free.

What pricing am I looking at for 2" x .5" wall? Is sleeving out of the question? If I can tap the 2" .5" wall then I don't have to deal with inserts...thats a good plan and should be pretty strong hopefully

 

[DHONDAGOD]

Ben, my rear lowers are 53" long, 2" x .500 and they havent moved. No tweaks, bends, deflections etc...

I have large RE Joints at both ends although I could have dont bushings at the axle end and the RE Joint at the frame end no problem. That was the original plan but I thought the RE Joint would run out of "twist" under articulation. (Wrong)


Pics in my build thread on pirate

http://www.pirate4x4.com/forum/showthread.php?t=342320


BTY the Detroit I got from you is still live and kicking in my front axle! Thanks again


Chris

 

[Eskimo]

If I can tap the 2" .5" wall then I don't have to deal with inserts...thats a good plan and should be pretty strong hopefully

One less failure point, but don't count on any cost savings.. ;p

I really like the 7075 links I'm running, but to each their own..

 

[Medusa]

Another option......

I use 1.5" o.d. 4340 with a .375"wall, heat treated to RC 40. Have beat the crap out of these for three years and they are still straight as an arrow.

 

[FJBen]

options options

Well here's a question. I can get a good deal but I have to buy the full stick...so I don't really need two different sized sticks So would building all links out of the 2" .50 wall be insane?

Or should I just go with .250 and sleeve the bottoms?

or

Is there enough material with the 2" 3/8" wall to tap for the 1" johnny joint shank?


PS: chris, glad that Detroit is put to some good use!!! The rig is looking great!

 

[redcorn]

Another option......

I use 1.5" o.d. 4340 with a .375"wall, heat treated to RC 40. Have beat the crap out of these for three years and they are still straight as an arrow.

you are a bad ass Jack

 

[Eskimo]

options options

Well here's a question. I can get a good deal but I have to buy the full stick...so I don't really need two different sized sticks So would building all links out of the 2" .50 wall be insane?

Or should I just go with .250 and sleeve the bottoms?

or

Is there enough material with the 2" 3/8" wall to tap for the 1" johnny joint shank?

There's a few online metals places that will sell you 3-4 foot pieces in the size you need, might save you money in the long run.

2" .500" wall is what you want to tap for a 1.25" shank.. you need an ID smaller than 1" to tap for a 1" thread.

 

[FJBen]

There's a few online metals places that will sell you 3-4 foot pieces in the size you need, might save you money in the long run.

2" .500" wall is what you want to tap for a 1.25" shank.. you need an ID smaller than 1" to tap for a 1" thread.

yeah I was lost in number land and thanks for bringing me back to the real world. ;p

2" .500" wall for 1.25" shank
1.75 x .500 wall for 1" shank Is that too small? Also keep in mind, I'm definitely not a hardcore rockcrawler...37's max, and nothing extreme. This is a daily driver weekend warrior rig.

I'm guess the "beef" way is the way to go.

 

[FJBen]

Sounds like I may go 2" x .500 wall tapped for JJ's on the lowers
1.5" .250 wall on the uppers

I posted this question on another board and they think I'm a little over the top in that size but it is a lot of Jeep people ;p

 

[Eskimo]

Sounds like a good size, Ben.. 1.25" shank JJ's all around I assume?

 

[FJBen]

Sounds like a good size, Ben.. 1.25" shank JJ's all around I assume?

I"m actually going to go Johnny joints on axle end, and bushings on the frame end since this is a daily driver...well my only daily driver ;p 1.25" shank JJ's tho.

 

[Eskimo]

That'll work, but what does bushing have to do with being a DD? The spherical ball in a JJ has a bushing around it, it absorbs impacts unlike a heim.. (and deflects a little too, gotta allow for some of that , unlike me..

 

[FJBen]

That'll work, but what does bushing have to do with being a DD? The spherical ball in a JJ has a bushing around it, it absorbs impacts unlike a heim.. (and deflects a little too, gotta allow for some of that , unlike me..

I guess I like the fact that that bushing should outlast the JJ and should not transmit as much noise/vib/etc through the vehicle.

I dunno maybe thats not the case.

I plan on running 36" lowers and the coils are up in the air. Either Jeep coils or Ford F150 coils.