Control arms

Tebbsjeep

Well-Known Member
Location
Ogden
I know the conventional way to run a control arm with one flex joint/one rubber end, is to put the flex joint on the frame side. But is there any reason to not install them the other way around with the flex joint at the axle end?
 

Herzog

somewhat damaged
Admin
Location
Wyoming
I've always ran mine with flex at the frame side and rubber at the axle side. For some reason it seems more logical that way, but thinking about it now I'm not sure why. Probably a case of "I've always done it that way"..?
 

Shawn

Just Hanging Out
Location
Holly Day
Great topic as my wifes JK has picked up a clunking noise in the rear end and for the life of me I can't figure out where the noise is coming from. I have decided to just purchase some flex joint rebuild kits and tear them down. What typically goes out first? Flex or rubber?
 

Tebbsjeep

Well-Known Member
Location
Ogden
The reason I ask is because I went to install my new joints on my Cherokee, and they don't fit the brackets that came on my long arm kit. It originally had heim joints, and I guess my new joints have a bigger body. However they do fit in the axle brackets.
 

RockChucker

Well-Known Member
Location
Highland
I always ran mine with rubber at the frame. Now I have Summit Machine Flex Joints on both ends. But I'm not too concerned about noise in my rig.
 

Tebbsjeep

Well-Known Member
Location
Ogden
Do you guys have any wobble in the threads before you tighten the jamb nuts? I feel like mine might have to much play, or maybe I'm inventing a problem that isn't there.
 

thenag

Registered User
Location
Kearns
Clayton on the XJ kits, has the rubber on the axle side. Well for their "standard" kit, the "Pro series Front Kit" doesn't have either end rubber, Johnny Joints all around.

Nathan
 

I Lean

Mbryson's hairdresser
Vendor
Location
Utah
I'm in the "rubber at the frame" camp.

And yes, some slop in the threads is not unusual--as long as it's not excessive.
 

DaveB

Long Jeep Fan
Location
Holladay, Utah
Is the clunking from when the rubber or poly bushings wear out?

- DAA

From what I have seen on ours the clunking comes from the flex joint loosening up. They aren't worn out and can usually be fixed by tightening them up (if the joint allows tightening). The Rubicon Express lifts we had in the past had the rubber end at the frame. I have also had clunks when the poly end of the control arm gets worn out.
 
  • Like
Reactions: DAA

gatchmo5710

Active Member
Define excessive. How much deflection?

Great question. This is standard test we do on our aircraft (im a heli mechanic) every inspection. The problem with most companys is their lack of tolerances or information about what is acceptable. Maybe teraflex gives a number.... but what you can do is go buy a grade 8 or better bolt with the same thread. Engage in the same amouint and compare wobble between the joint and the new bolt. If its close run it.

And i put all my soft joints at frame, hard at axle.
 
Last edited:

gatchmo5710

Active Member
This is from my manual with 5/16 fine thread bolt. Lossen jam nut, check movement at attach bolt hole.
If total movement exceeds 1/16 inch
(1.5875 mm) rod assembly must be
replaced with serviceable parts.
(f). Movement less than 3/64 inch
(1.190625 mm) is considered negligible.
(g). If movement is between 3/64 and 1/16
inch (1.5875 and 1.190625 mm),
inspect rod threads, step (6)., or rod
insert, step (7).
 

mesha

By endurance we conquer
Location
A.F.
Great topic as my wifes JK has picked up a clunking noise in the rear end and for the life of me I can't figure out where the noise is coming from. I have decided to just purchase some flex joint rebuild kits and tear them down. What typically goes out first? Flex or rubber?

On the teraflex joint the rubber will last WAY longer than the flex joint.
 

DAA

Well-Known Member
That's interesting.

The flex joints on my LJ don't have any way of tightening them. But they have over 100,000 miles on them and haven't started making any noise yet I guess that's okay. A good thing, too, since they are on all 16 ends. They do have zerks and have been greased every time I change the motor oil at 4,000 miles.

The Clevite bushings in the factory arms were showing some wear when they came off at less than 20,000 miles though.

- DAA
 

mesha

By endurance we conquer
Location
A.F.
That's interesting.

The flex joints on my LJ don't have any way of tightening them. But they have over 100,000 miles on them and haven't started making any noise yet I guess that's okay. A good thing, too, since they are on all 16 ends. They do have zerks and have been greased every time I change the motor oil at 4,000 miles.

The Clevite bushings in the factory arms were showing some wear when they came off at less than 20,000 miles though.

- DAA
The large flex joints do okay if you keep them greased. The small flex joints need to be replaced all too often especially the ones located close to the exhaust in the long arm JK/JKU kits.
 
  • Like
Reactions: DAA

Herzog

somewhat damaged
Admin
Location
Wyoming
I'm a huge fan of good clevite bushings. I was happy when Teraflex adopted the use of them. They absorb impact and vibration really well and last a long time if setup properly (including not tightening until the suspension is at ride height)

You do have to be careful, there are lower quality clevite bushings out there that do not last very long, especially the ones with a 'D' window cut out of the rubber.
 
Top