Control arm thread exposure

Aggressive1

Aggressive1

Well-Known Member
Joined
Apr 19, 2005
Location
Myrtle Beach
Building a Tri link set up for the TJ. Using 1.75 .250 DOM. I am making both the upper and lowers adjustable for tuning AND to be able to push the axle out farther when the gas tank it gone and also move it forward a couple of inches in case the current set up tries to "self clear" on the gas tank. I am just wonder if I am using B-7 quality 1.25" threaded rod and a 1.25" id threaded insert, how much of the rod should I have sunk in each end of the control arm as a minimum and how much thread can I have exposed? I know the threaded rod may be a week point. Is 3" in the fixed end and 3" threaded into the instert enough? and a maximum of 6" exposed ok?
 
I've always heard the rule double the diameter for thread engagement, but personally, I wouldn't be comfy with 6" of exposed threads.
 
Thanks Rich....I was starting to wonder if all you fawkers where at lunch or something.

Now that you say the double diameter thing, I beleive I have heard that before too. Thanks

So the threaded rod may not be up to the beating that the 1.75 .25 DOM is?
 
Aggressive1 said:
So the threaded rod may not be up to the beating that the 1.75 .25 DOM is?
Click to expand...

No, it won't. And frankly, 1.75" .250 DOM isn't going to take a whole lot of a beating. It may last a while, but the first time you smack it good, it'll tweak.

You're probably better off building new arms when you decide to extend the WB.
 
saf-t scissors said:
You're probably better off building new arms when you decide to extend the WB.
Click to expand...

And if you find that the 1.75 tubing didn't hold up, maybe you can cut your old arms and sleeve them with something bigger to make them longer.
 
thecarman said:
And if you find that the 1.75 tubing didn't hold up, maybe you can cut your old arms and sleeve them with something bigger to make them longer.
Click to expand...


I like that idea....alot. The longer they are the weeker that will be anyways. SO I will see how the suspension is gonna work and then I can go back and adjust them out and sleeve them with 2.25" .250 wall or 2" .120 wall.

No the uppers are gonna be plenty strong enough with the same specs right?
 
Uppers are way overkill.. even 1.5" .120 is OK for uppers, but I dunno that I'd get a warm fuzzy using that... What you've got should work just fine for uppers...

I know guys using ~36" lower links out of lesser material that have bent a little after a season of HARD use.. Run it for now.
 
I was running 33" long Terra flex lowers and they are 1.75 and neck down to 1.5" so I must not wheel it hard enough :lol: . But really, they may be a different material. The new ones are 36" so I won't worry about it until I wanna thread them out to 39" to 40" and just sleave em.
 
My long arms are made from 1.75 x .250 DOM and are just over 30" long and they have held up fine under my XJ for 4 years now. Anything longer I would sleeve. The rule for how much thread needs to be present is one and a half times the diameter. I have maybe 1.5 inches of thread showing on my LCA's. I wouldnt go much past that. 6" is a bit much to be exposed in my opinion. Make a set with 6" exposed and run them for a few rides so you can fine tune everything then once your happy build a good set with less thread or make them solid tube.

AARON
 
Back
Top