• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Adj. CA's Need lock nut?

HaleYes

HaleYes

NAXJA Forum User
Location
Clay County, IL
What's the general opinion on weather or not a lock nut is needed on the adj. threads of CA's? Both ends are mounted, it's not going to lengthen/shorten on it's own...right? Over time if a lock nut isn't used, I suppose it could waller-out the threads..right? I need to decide if I need to find some lock nuts or not on my newley aquired CA's. They did not come with them.

TIA guys.


Haleyes
 
imho no you dont need them because all they really do is keep them from having a 1/10,000 of an inch play ( or something like that ) and the wear would be minimal

just my .02
 
I think it might depend on what ends are used: if you're using bushings then you might be able to get away. If you're using something like RE superflex joint on one end I think you want a lock nut so that it stays in a particular orientation while static: otherwise the joint might just get all crooked and wedged in the mount.
 
Rusty's uppers and lowers, so there OEM bushings.
 
You must use lock nuts on any sort of threaded part, with the exception of an Acme thread.

Threading that is not preloaded with some form of tension device will not only have a tendancy to move parallel to the loading, but also perpendicular to it. Because of the play inherent in all threaded parts, the stress is pulling the threading in and out, but also causing a binding load. This will quickly wear the treads, and has the potential to actually split the treaded sleeve if loaded heavily and repeatedly.
 
CRASH said:
You must use lock nuts on any sort of threaded part, with the exception of an Acme thread.
Click to expand...

Rusty's are ACME thread. Why are ACME threads the exception? Would it be a bad thing to use a lock nut on ACME threads?

Thanks for the info.:wave:
 
Last edited:
Crash managed to eloquently state what I've been trying to put into words for the last couple of hours.

The difference is in the thread profile. Standard bolt threads have (relatively) sharp corners. Acme threads are more square, and have a flat top.

There's a bunch of info available on the 'net (Google can help) and a good machinist's handbook should shed some light on the matter.

As far as personal experience goes, I've got RE adjustable arms on mine. I didn't realize that a jam nut had come loose, and that's what was making a clunk. By the time I'd figured it out, it'd jammed itself firmly together. Normally, I'd say this wasn't a problem, but I was trying to adjust wheelbase at the time.
 
CRASH said:
You must use lock nuts on any sort of threaded part, with the exception of an Acme thread.

Threading that is not preloaded with some form of tension device will not only have a tendancy to move parallel to the loading, but also perpendicular to it. Because of the play inherent in all threaded parts, the stress is pulling the threading in and out, but also causing a binding load. This will quickly wear the treads, and has the potential to actually split the treaded sleeve if loaded heavily and repeatedly.
Click to expand...
x2

Although I at one time had rusty's UCA and I used a locknut because I was tired of the clunking.
 
if you put a lock nut on rustys junk arms, er uhh...control arms, because they dont use a flex joint, the arm would bind one way, and undo the lock nut the other
 
rustys claims that you flex better w/o the lock nut becasue the twisting of the threads adds to the flexing. it all sounds half assed to me. and they cant stop saying that if you dont run the lock nut then you need to grease it like crazy. i think its all crap. and i dont think that rustys runs acme threads.. as far as i know.
 
stupidfast said:
and i dont think that rustys runs acme threads.. as far as i know.
Click to expand...

Rusty's Offroad said:
The lower adjustable control arms are fabricated of .250 thick 2 inch DOM tubing and have a formed mandrel bend to offer more flex and articulation. 1.5 ACME threads are used to give strength, adjustably and to offer a twist type articulation. Factory OEM bushings are installed and are powder coated in a glossy black finish. Our adjustable arms give about 4 inches of adjustment. We highly recommend using a lithium grease in our control arms and be sure to pack it full!
Click to expand...
 
I used his UCA in my long arms (radius style) so no twisting was needed. It did have acme thread and it did clunk all the time due to the large backlash.
 
I've got a clunk now. Hard to tell where it is comming from too. It's pretty loud as well. It may very well be the CA's, but I'm not sure yet. It seems to only happen when I'm turning and going up/down a slight grade. It's just one clunk. Does this sound like symptoms of a CA clunk?
 
i run rustys la kit fortunatly i greased th shit out of them since day one and they havent gotten sloppy even after 40,000 hard miles. however they can wear and clunk, id also check the sway bar bushings they can make some killer clunking noises when bad.
 
Haleyes said:
I've got a clunk now. Hard to tell where it is comming from too. It's pretty loud as well. It may very well be the CA's, but I'm not sure yet. It seems to only happen when I'm turning and going up/down a slight grade. It's just one clunk. Does this sound like symptoms of a CA clunk?
Click to expand...
You didn't put nuts on them did you? :twak:
 
I installed new Rusty's upper and lower ACA's and had loud clunking on both side depending on what side hit something. I installed locknuts with acme threads on the lowers only and the clunking is gone.
 
seanR said:
You didn't put nuts on them did you? :twak:
Click to expand...

No, I did not.
 
You must log in or register to reply here.

Similar threads

N
2000 XJ, high miles, lots of new parts, still have vibration
Replies
10
Views
1K
N8N_99xj
N
S
Very stubborn front axle nut
Replies
14
Views
880
IslanderOffRoad
IslanderOffRoad
H
The all inclusive guide to ford 8.8 swap
Replies
7
Views
6K
Havoc_protocol
H
M
Need Adjustable Tracbar Recommendation
Replies
18
Views
2K
Johnnie Walker
Johnnie Walker
C
1999 XJ 4 door lifted on 35s with Dana 44s & extras – under 76K miles
Replies
5
Views
5K
Gjeep
G
Back
Top