Jba uca fitment

mercdudecbr600

Full Access Member
Joined
Oct 3, 2018
Messages
250
Reaction score
65
Hi all. Just installed jba uca on my kj and found a few minor fitment issues that you all should be aware-of. The jba bushings are a little more than 1/8” wider than stock uca bushings and therefore you have much less wiggle room inside the frame mounting pocket. Jba manual say to expand the pockets but give no other instructions. I tried to fit mine as-is but it was too tight and no amount of hammering would make them seat properly. The bushings are 2” wide so… I cut a 2x4 to 2 1/8” by 18” and used a sledge to wedge them into the pockets and then levered the 2x4” over when fully seated. Gave JUST enough space to get the uca in fully. After putting lubricant on the bushings I was able to get them in.

By comparison to stock uca, These aren’t a snap to get in. Hope this helps someone else.
 

duderz7

Full Access Member
Joined
Jan 20, 2016
Messages
959
Reaction score
527
Location
Weiser, ID
First I've heard of it, and many have put them in. Is it possible your jeep had some other replacement uca's that were perhaps undersized and the pockets were squashed at install?
 

tommudd

Moderator
Staff member
Moderator
Joined
Jul 14, 2005
Messages
22,053
Reaction score
3,216
Location
Southeastern Ohio
Hi all. Just installed jba uca on my kj and found a few minor fitment issues that you all should be aware-of. The jba bushings are a little more than 1/8” wider than stock uca bushings and therefore you have much less wiggle room inside the frame mounting pocket. Jba manual say to expand the pockets but give no other instructions. I tried to fit mine as-is but it was too tight and no amount of hammering would make them seat properly. The bushings are 2” wide so… I cut a 2x4 to 2 1/8” by 18” and used a sledge to wedge them into the pockets and then levered the 2x4” over when fully seated. Gave JUST enough space to get the uca in fully. After putting lubricant on the bushings I was able to get them in.

By comparison to stock uca, These aren’t a snap to get in. Hope this helps someone else.
First time I heard of that most fall right in, maybe they did not get the bushings pressedm in far enough
As far as the 2x4 , not the right approach but i guess it worked for ya
Opening the pockets is completely different than what you are thinking
Back years ago we cut some of the body away below the UCA to allow more flex, but overr time we found that they would self clearance themselves so that was not needed
I have installed over 45 -50 sets beginning with the original black JBA arms sold by Al Handy, ( the original JBA ) then the Gen 4 then onto the 4.5s , never an issue
 

tommudd

Moderator
Staff member
Moderator
Joined
Jul 14, 2005
Messages
22,053
Reaction score
3,216
Location
Southeastern Ohio
First I've heard of it, and many have put them in. Is it possible your jeep had some other replacement uca's that were perhaps undersized and the pockets were squashed at install?
That sounds like what may have happened somewhere back a few years ago
 

mercdudecbr600

Full Access Member
Joined
Oct 3, 2018
Messages
250
Reaction score
65
First I've heard of it, and many have put them in. Is it possible your jeep had some other replacement uca's that were perhaps undersized and the pockets were squashed at install?
Possible but seems unlikely. I had stock hd but aftermarket replacement uca.

There’s a big note under “tips” by jba to open the pocket up. Just like you guys I thought - nah not a problem. But it was, oh it was. And ya 2” box metal would have been ideal tool for the job but I didnt have that. My first and only attempt worked with the 2x4 but I was ready to get more serious. Even with my amateur spreading it wasn’t an easy fit.
Hopefully no one else has these problems but if they do this is here.
 

mercdudecbr600

Full Access Member
Joined
Oct 3, 2018
Messages
250
Reaction score
65
First time I heard of that most fall right in, maybe they did not get the bushings pressedm in far enough
As far as the 2x4 , not the right approach but i guess it worked for ya
Opening the pockets is completely different than what you are thinking
Back years ago we cut some of the body away below the UCA to allow more flex, but overr time we found that they would self clearance themselves so that was not needed
I have installed over 45 -50 sets beginning with the original black JBA arms sold by Al Handy, ( the original JBA ) then the Gen 4 then onto the 4.5s , never an issue
Oh. So “opening up” means cutting the frame rail? Why would jba suggest that?
 

duderz7

Full Access Member
Joined
Jan 20, 2016
Messages
959
Reaction score
527
Location
Weiser, ID
When they talk about opening up the pockets its the sheet metal at the bottom to allow for more down travel.
 

liron sasson

Member
Joined
Jul 2, 2019
Messages
73
Reaction score
8
Hi all. Just installed jba uca on my kj and found a few minor fitment issues that you all should be aware-of. The jba bushings are a little more than 1/8” wider than stock uca bushings and therefore you have much less wiggle room inside the frame mounting pocket. Jba manual say to expand the pockets but give no other instructions. I tried to fit mine as-is but it was too tight and no amount of hammering would make them seat properly. The bushings are 2” wide so… I cut a 2x4 to 2 1/8” by 18” and used a sledge to wedge them into the pockets and then levered the 2x4” over when fully seated. Gave JUST enough space to get the uca in fully. After putting lubricant on the bushings I was able to get them in.

By comparison to stock uca, These aren’t a snap to get in. Hope this helps someone else.
so glad to find this post!! i had the same issue! very hard to install those bushings and insert the bolts with such pressure!! very hard to play with the arm !
really think to change again to oem!
 

liron sasson

Member
Joined
Jul 2, 2019
Messages
73
Reaction score
8
Hi all. Just installed jba uca on my kj and found a few minor fitment issues that you all should be aware-of. The jba bushings are a little more than 1/8” wider than stock uca bushings and therefore you have much less wiggle room inside the frame mounting pocket. Jba manual say to expand the pockets but give no other instructions. I tried to fit mine as-is but it was too tight and no amount of hammering would make them seat properly. The bushings are 2” wide so… I cut a 2x4 to 2 1/8” by 18” and used a sledge to wedge them into the pockets and then levered the 2x4” over when fully seated. Gave JUST enough space to get the uca in fully. After putting lubricant on the bushings I was able to get them in.

By comparison to stock uca, These aren’t a snap to get in. Hope this helps someone else.
do you have pictures of what you done?
 

mercdudecbr600

Full Access Member
Joined
Oct 3, 2018
Messages
250
Reaction score
65
No, sorry. But what I did is basically shove a 2x4 into the pocket via hammer. That opened it up enough to get it in but just barely.
 

duderz7

Full Access Member
Joined
Jan 20, 2016
Messages
959
Reaction score
527
Location
Weiser, ID
If I run into this problem (I've purchased the bushing kit but not installed it yet) I'll put a bolt through the mount with 2 nuts and washers threaded on inside the pocket and use it like a mini internal press/spreader thingamabob.
 
  • Like
Reactions: klc

Johnny O

Turning dirt roads and dead-ends to dust.
KJ Supporting Member
Joined
Apr 29, 2021
Messages
1,790
Reaction score
1,840
Location
Bellevue NE
I just heated the whole assembly at 125F for an hour. Slipped right in. Other than proper preventative greasing, haven’t touched them for months.
 

tommudd

Moderator
Staff member
Moderator
Joined
Jul 14, 2005
Messages
22,053
Reaction score
3,216
Location
Southeastern Ohio
Of all the sets I have installed never had any issues at all
no shoving, bending, pushing , banging, just throw them up and install the bolts
maybe like some human body parts , shrinks with age ??
 

mercdudecbr600

Full Access Member
Joined
Oct 3, 2018
Messages
250
Reaction score
65
If I run into this problem (I've purchased the bushing kit but not installed it yet) I'll put a bolt through the mount with 2 nuts and washers threaded on inside the pocket and use it like a mini internal press/spreader thingamabob.
That's a good idea, actually. I think the deal is that I lost about 1/16-1/8" in the pockets because the previous set had smaller (width) bushings by that much. But however you decide to do it, if you have the same issue then they aren't going in without a serious fight and even after opening them up they were tight tight tight. Or I should say, very precisely fitting. Worthwhile upgrade though - drives great, much better spring clearance, great alignment specs, more suspension travel, etc.
 

Latest posts

Members online

Top