The Currie Johnny Joints have a one-piece forged shank that's threaded...

Those are what I used on mine. 1" thread though.

FWIW the 1.25" heim joints that Poison Spyder sells have a 2.125"-long shank. Your figure sounds a little low.

 

http://www.polyperformance.com/shop/product.php?productid=388&cat=167&page=1

poly has them with a 1.25" shank as well. Does anyone know if these also use a 9/16" bolt. That worries me a little. Dont know if it should or not. I never broke one on my TJ, but I also wasnt running 1250 pounds of rims, tires, and axles.

I also checked into curries web site. They make a 3" joint that uses a .75" bolt, bet that fukr is beefy...

 

The Poison Spyder 1.25" heims use a 1" through bolt...I know that much.

Not sure about the 1.25" shank JJs though.

 

E-Mail the guys at www.evolutionmachine.com and ask them,.. they are all made on site so I am sure they can accomodate what you need

 

E-Mail the guys at www.evolutionmachine.com and ask them,.. they are all made on site so I am sure they can accomodate what you need

did you read my post, i already said I know they CAN do what I want, but I cant afford it

I will PM them. and see what they can do for me...

 

I was also going to suggest EVO, but try those johnny ends. They look pretty stout.

 

Just about all the jam nuts I have seen on big rod ends are cut down to about half height. Even jam nuts are just too tall in the big stuff. At any rate the rod end will break at the ball end before the threads will ever break. Thread engagement just isn't that much of a problem with something this big.

 

I'm running a summit machine flexx joint and each is welded to 6 inches of 1.25 allthread

 

I just ordered the jj joints 1.25 shaft from poly I'll let you know the size of the hole,and the length of the shaft when they get here on wednesday,or get a hold of PIG from poly he'll let you know.

 

1.25 JJ use 9/16 thru bolts. I'm running them on my XJ
-Joel

 

Just about all the jam nuts I have seen on big rod ends are cut down to about half height. Even jam nuts are just too tall in the big stuff. At any rate the rod end will break at the ball end before the threads will ever break. Thread engagement just isn't that much of a problem with something this big.

If I remember right, I think a general rule of thumb is that thread engagement should be about equal to the diameter of the threaded thing.

That being said, I've seen heims fail by ripping the ball out, I've seen them bend at the shank and break that way, but I've never seen one pull out of a tube insert and strip the threads out.

 

IIRC max effective thread engagement =1.5xdiameter.

so for a 1.25 diameter shank optimum thread engagement would be 1 7/8"

again not gospel just a rule of thumb. like stated above most joints fail at the ball not the threaded shank.

 

Yeah, it's somewhere in between the two. I remember actually calculating it out for an M12-10.9 bolt and it worked out to around 12.5mm of engagement, but a factor of safety on top of that wouldn't be a bad thing.

 

I know you Plan on trying to keep as much of the joint shank inside the tube as possible. But if you have 2" of shank, and a half inch of it is jam nut, then you at 1.5" and if you want to thread it out a half inch now you are at 1" of thread inside the adapter... not the end of the world just not ideal. At that point you have no pressure on the inside of the tube, it is all in the adapter. More stress on the welds. I doubt it will be a problem, but I would enjoy a 3" shank

 

At that point you have no pressure on the inside of the tube, it is all in the adapter. More stress on the welds. I doubt it will be a problem, but I would enjoy a 3" shank

That's not entirely true, unless your tube adapter is just butt-welded to the end of the tube. If it's got that part to extend down inside the tube then you'll still be relieving a lot of bending stress from the weld.

 

yeah, that is true, I was just thinking the tube adapter is 1.5 OD and .125id for the part inside the tube. It is definatly better than butt welded, but I would think it would be even better to have the threaded shank in there as well.

I wonder what a good test for this would be. Get a heim, thread it out a so only 3/4 of an inch is in the adaptor, and put it in the press with the 2" and the end of the heim supported, nothing under the adapter. See if the tube adapter gives or the threads on the heim bend???

 

Heims aren't really designed for bending though. They're meant to maintain a pure tension load under misalignment. If you've got that much bending happening, I'd suggest re-working something in your design.

The only way you should ever have bending like that anyway is from landing/resting the vehicle on one of the links.

 

Its really much more complicated to calculate the optimum thread engagement accurately. If anyone has a Machinery's Handbook(vol 26) it can be found on pg 1490.

I didnt read thouroughly but the TPI, class of thread, etc... all plays a factor
more variables than I thought. After reading it, it makes sense. It even gives a formula to cacluate which thread will fail first the external or internal.

pretty interesting reading actually

 

what about using joints from the top link on a tractor 3 point hitch? they have at least 7 inches of thread.

 

what about using joints from the top link on a tractor 3 point hitch? they have at least 7 inches of thread.

I believe the ball and seat on those are made to much lighter tolerances than the Aurora or Q7 heims. From what I've seen they wear a lot faster, which makes 'em sloppy and more susceptible to breaking from shock loads.

But then you also see the guys that have run 'em for two years and they're fine. So who knows.

 

The only way you should ever have bending like that anyway is from landing/resting the vehicle on one of the links.

That is the exact thing I worry about

 

I ran those tractor joints on my pro areana truck for 4 years and had no problems they just wear fast and they are loud

 

That is the exact thing I worry about

If that's the case, why not just spend top dollar for 8 joints, for your lower links? It's not like the uppers will ever see that kind of load, and you'll split the difference vs spending the big money on Evolution joints throughout.

 

i have seen one pull out but it was a 3/4" heim and it was on a trac bar and the asshat only had about a 1/2" of thread engagement but i guess thats what you have to deal with when you let someone with a short arm 6" lift on a rubicon tag along with your group. It won't happen again thats for sure

 

I just ordered the jj joints 1.25 shaft from poly I'll let you know the size of the hole,and the length of the shaft when they get here on wednesday,or get a hold of PIG from poly he'll let you know.

I got the JJ joints in, they have 1.25x3.5 shaft 9/16 hole.:smokin: