I am building LCAs for my TJ and have decided on Johnny joints over POREs but I need some adjustment, I like the way RE has their control arms but I am unsure of what threaded rod to use.

Should I use ACME or course thread? (it will be 1 1/8" rod)

What material should I use? I can get B7, B16, L7, 8.8 zinc plate or 4.6 zinc plate.

I don't have the ability to TIG so please keep that in mind.

I don't expect to get flex from this joint like Tera does, this should only be for adjustment.

If one of you guys/gals has a good vendor for this stuff (either the thread or the joints) now would be a good time to plug them as I haven't forked over the $ yet. :D

I don't know crap about the different materials the you posted, but I do know this...Use fine thread! HTH.

Why? Are you talking only for fine adjustment? RE uses course and it should have more engaugement of the threads then fine.

I just don't have the capability to harden anything with any quality and I doubt regular all thread is going to put up with my crap. With any luck there will be less then 1" of it exposed but that 1" will be my weak link. It will really piss me off if I bend one at the adjustment and have to fab these all over again.

fine thread is stonger, it has more engagement per inch than course
should use course thread if the bolt is stonger than the material it is being used in
don't kill me because i use course threads all the time

Kill ya? I just want some advise thanks for what you have donated. Nobody has any advise on material though, come on guys I would like to learn from your mistakes rather then die figuring it out.

Nevermind here is a link for anyone else with questions.

http://www.americanfastener.com/techref/grade.htm

if im following what you want to do, get yourself some solid round stock and have some one put threads on there for ya......


me and my brother will be doing this for our jeeps.....

Two reasons to use fine thread...kinda related to each other.
First: already been mentioned- more engagement per inch.

Second: More engagement translate to longer life before the wear out.

Originally posted by badassjeepguy
if im following what you want to do, get yourself some solid round stock and have some one put threads on there for ya......


me and my brother will be doing this for our jeeps.....


That has been considered but I don't think mild steel or cold rolled bar will be stout enough, I could be wrong though. It is worth the $30 for my piece of mind but it is probably overkill.

Right now I am torn between L7 and 8.8 zinc plated, anybody know how the zinc plate will effect welding?

I'd go bigger than 1 1/8" but I like overkill. I used 1" on my panhard bar for the rear 3 link on my old 4runner worked good never bent or nothing and it was exposed for about 4". It looked like a weak spot but I guess the forces on it were'nt side loading it. on a suspension link you can get a lot of stress on it when the weight of the truck is sitting on it. I bent two 1.5 by .25 dom lower links on the 4runner. I'd use them on the top links only (so you can adjust the castor and make the lowers solid.

I would reconsider L7 - This is a low temp. service spec. I am not 100% sure but I would be worried about how the high heat of welding would affect them. I know that in Process Plant services that L7 studs become very brittle when exposed to high heat. My personal choice would be B7 - easy and cheaper to get. Just the common zinc plated studs you would have to grind down past the zinc plating in order to avoid zinc embrittlement when welding. Another saftey factor when welding on Zinc coated metals is metal fume fever/Zinc chills - it feels like the worst Flu you have ever had!!:barf: I would just go to a local industrial supply shop and order 4 B7 studs in the length you need - UNF might be a tough thing to find in 1 1/8" though. If you lived anywhere near me I would just give you some.

Originally posted by jasonmt
I would reconsider L7 - This is a low temp. service spec. I am not 100% sure but I would be worried about how the high heat of welding would affect them. I know that in Process Plant services that L7 studs become very brittle when exposed to high heat. My personal choice would be B7 - easy and cheaper to get. Just the common zinc plated studs you would have to grind down past the zinc plating in order to avoid zinc embrittlement when welding. Another saftey factor when welding on Zinc coated metals is metal fume fever/Zinc chills - it feels like the worst Flu you have ever had!!:barf: I would just go to a local industrial supply shop and order 4 B7 studs in the length you need - UNF might be a tough thing to find in 1 1/8" though. If you lived anywhere near me I would just give you some.

DOH I knew that too. I was just thinking about when in operation it doesn't need to deal with heat. Thanks for that one.

B7 it is unless anyone else knows better.