Jeep Wrangler PCM and module repair and replacement

Tips & Tricks: Adjusting Rear UCAs

Hasselblad

Hasselblad

TJ Enthusiast
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Joined
Oct 10, 2020
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Utah Mountains
Another week, another project. Last week I tucked the tummy of the rubi with the Terraflex plate and now moving on to adjusting the rear UCAs to fix the pinion angle. I took out the "front" bolt from the driver side, then realized that the brake line bracket needed a bit of a soak in WD40. So I moved over to the passenger side and began to take out it's front bolt. It was toward the end of a long day after work and realized "hey, there's a frickin muffler in the way."

I don't know if anyone has tips or tricks, or just mental support at this point. At the age where little things, especially underneath the jeep, really irritate in short order. Took a break for the rest of the night at that point.

The UCAs are adjustables, with the johnny joint rearward. Which is unfortunate in regard to getting to the lock nuts.
 
I usually use a crowfoot on a 1/2 in drive socket to break free and tighten down the jam nuts on control arms. That will give you more options to get it on the nut and use leverage.
 
WD40 as a penetrating oil isn't very good. Neither is PB Blaster. Liquid Wrench is much better, and Kano Kroil is a little better than that. The best is the cheapest, a 50/50 ATF/Acetone mix. @Artsifrtsi mentioned it here.

If the muffler is a problem for getting the bolt out, the exhaust system is partially on rubber hangers. You might have to loosen the joint at the catalytic converter, and then you may be able to shove the muffler enough to get the bolt out. And maybe put the bolt in the opposite way when reassembling.
 
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OldBuzzard said:
WD40 as a penetrating oil isn't very good. Neither is PB Blaster. Liquid Wrench is much better, and Kano Kroil is a little better than that. The best is the cheapest, a 50/50 ATF/Acetone mix. @Artsifrtsi mentioned it here.

If the muffler is a problem for getting the bolt out, the exhaust system is partially on rubber hangers. You might have to loosen the joint at the catalytic converter, and then you may be able to shove the muffler enough to get the bolt out. And maybe put the bolt in the opposite way when reassembling.
Click to expand...

But gotta use up all of my existing WD40 8(
ATF = tranny fluid?

I had thought to remove the bolt from the rear of that CA and just spin that end without removing the front end bolt, which led me to wish that I had been able to get tickets for the Chris Isaak show (for my wife) so I could get away with dropping some cash on double adjustables while I am messing with this.

Any labor day sales been mentioned of late?
 
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I use the ratcheting box end of a combination wrench on that one then just hold the flag nut once it's loose enough to drag. Still mildly annoying, especially since my wrenches are shorter than I'd like more times than not.
 
When I got home last night I decided to reach out to the shop that has done some of my work in the past, and am going to just have them do the pinion adjustment. I was close to shelling out for double adjustables, but said F it, may as well toss that money at a shop. Just have to limp about 3 miles to the shop with the pinion way out, and hope I do not screw up the ujoints on the way.
 
Hasselblad said:
When I got home last night I decided to reach out to the shop that has done some of my work in the past, and am going to just have them do the pinion adjustment. I was close to shelling out for double adjustables, but said F it, may as well toss that money at a shop. Just have to limp about 3 miles to the shop with the pinion way out, and hope I do not screw up the ujoints on the way.
Click to expand...

Double adjustables make this job a relative breeze. If I was doing a new build, I would not opt for anything else.
 
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The shop got back to me an apparently had no clue how to adjust a pinion angle with adjustable UCAs,

Tempted to tell them to put it up on the frigging lift and I will do myself.

:mad:
 
Hasselblad said:
The shop got back to me an apparently had no clue how to adjust a pinion angle with adjustable UCAs,

Tempted to tell them to put it up on the frigging lift and I will do myself.

:mad:
Click to expand...

Anyone using a lift to adjust pinion angles is as clueless as your shop is. 😉
 
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jjvw said:
Anyone using a lift to adjust pinion angles is as clueless as your shop is. 😉
Click to expand...

Full on wheel lift.

Turns out "we do not have angle finders, and this is more a job for offroad shop". Looks like I will be limping it back home, risking the ujoints, and doing the shit myself afterall.
 
Hasselblad said:
Full on wheel lift.

Turns out "we do not have angle finders, and this is more a job for offroad shop". Looks like I will be limping it back home, risking the ujoints, and doing the shit myself afterall.
Click to expand...

Still a waste of time using a lift. So is an angle finder. Make the adjustment and go for a highway drive to check for vibes. If they are still there, dive into a parking lot, readjust and check again.
 
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jjvw said:
Still a waste of time using a lift. So is an angle finder. Make the adjustment and go for a highway drive to check for vibes. If they are still there, dive into a parking lot, readjust and check again.
Click to expand...

The RCAs are only single adjustable. Not as fun.

Will do them this weekend and give serious thought to double adjusts while on labor dayy sale. On the bright side I have a couple spare spiders, in the event I ruin the ujoints
 
Jeep is back home. Going to get it done this weekend with the single adjust ucas, and I put in a order for a pair of double metalcloaks.
 
holy shit, losing it now

Front passenger side bolt blocked by muffler. OK, I'll just remove the rear bolt. Rear bolt blocked by the rear spring. Who in the F designed this?
 
Do you have a good set of combination wrenches? If I remember correctly that's all it takes. Unless you're saying that the bolt is pointed towards the spring and can't be pulled out, in which case all it takes is flipping the bolt next time you take it out.
 
That'll Buff said:
Do you have a good set of combination wrenches? If I remember correctly that's all it takes. Unless you're saying that the bolt is pointed towards the spring and can't be pulled out, in which case all it takes is flipping the bolt next time you take it out.
Click to expand...

Correct. Bolt is pulling toward the spring, akin to the front one pulling toward the muffler. I kind of feel whomever put these UCAs on was doing it this way to get more future business. This is asinine. I mean all I needed was ONE of the bolts to be able to be removed to make the adjustment. Guess I will jack up the passenger side to see if the bolt can be pulled between curves of the spring.

Edit: Jacking up the bumper allowed enough flex to slide it out between spring opening.

Edit: Getting the jam nut loose on the passenger side was fun. Had to put the giant wrench on the nut, loop a ratchet strap through the handle, feed it through the wheel rim, and tug. Hey, it worked. The degrees were about 10 degree different so after a bit of pivoting with bottle jack I got it within 1. Lengthened the pass side UCA and on to the driver's side, which I may just take completely off in order to deal with the jam and put it back on. Leaving the bottle jack as it is until I get that UCA on, adjusted, and snugged down. Once I let the bottle down I suspect that I will get a little more of a degree, so HOPING it is smooth as butter.
 
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