Adjusting control arms

[Mike_H]

I was dialing in my pinion angle this weekend after my tummy tuck. I followed the "rules" and removed one upper arm (passenger in this case) and used the driver's side to get the pinion angle just right. After that, I started working on installing my angled trackbar bracket. Well, wouldn't you know, the driver's side UCA had to come of to access the bolts. For some reason, I had to extend my passenger side UCA to get the pinion angle back. I lost a couple degrees between removing the driver's side, jacking the rear up, lowering it down, and trying to install the arm again.

What gives?

 

[Brianj5600]

Was all this done with the Jeep on the ground?

 

[freedom_in_4low]

I don't think you can make any of your other adjustments until you have the track bar connected. Due to the mild triangulation of the control arms, adjusting them with the track bar off makes the axle want to shift side to side instead of doing what you want. That's at least what I experienced; screwed around trying to get my pinion angle right and never could get there. Realized what was happening and had to start over.

 

[Mike_H]

Was all this done with the Jeep on the ground?

Yup, on the ground on its tires

 

[Mike_H]

I don't think you can make any of your other adjustments until you have the track bar connected. Due to the mild triangulation of the control arms, adjusting them with the track bar off makes the axle want to shift side to side instead of doing what you want. That's at least what I experienced; screwed around trying to get my pinion angle right and never could get there. Realized what was happening and had to start over.

The track bar was attached both times. That is a good point though. I changed my track bar position in between setting the pinion angle each time. That might be it

 

[707kevin]

I've noticed that if you still have the rubber UCA bushings on the axle, that when you are doing your adjustment on the driver side, the rubber is a bit compressed. When passenger side UCA gets installed, you tend to leave it in place loose. Now if you take out the driver side UCA, cycle the suspension or move anything like the trac bar, roll the tires back or forth, etc.. you put the strain on the passenger side UCA. Now the driver side doesn't quite want to go to it's home. If you adjust this and install - it will be a degree or two off.

This would only be an issue with rubber UCA bushings. I have Savvy control arms, but still rocking the rubber upper bushings on the axel.

 

[freedom_in_4low]

I've noticed that if you still have the rubber UCA bushings on the axle, that when you are doing your adjustment on the driver side, the rubber is a bit compressed. When passenger side UCA gets installed, you tend to leave it in place loose. Now if you take out the driver side UCA, cycle the suspension or move anything like the trac bar, roll the tires back or forth, etc.. you put the strain on the passenger side UCA. Now the driver side doesn't quite want to go to it's home. If you adjust this and install - it will be a degree or two off.

This would only be an issue with rubber UCA bushings. I have Savvy control arms, but still rocking the rubber upper bushings on the axel.

I'm fairly sure he's referring to the rear, but yeah the front can get weird since the jacking point to adjust the pinion is offset instead of centered. This is where double adjustable arms pay for themselves.

 

[707kevin]

I'm fairly sure he's referring to the rear, but yeah the front can get weird since the jacking point to adjust the pinion is offset instead of centered. This is where double adjustable arms pay for themselves.

Gotcha. Front was on my mind since I just tweaked it a bit the other weekend.

 

[Mike_H]

I've noticed that if you still have the rubber UCA bushings on the axle, that when you are doing your adjustment on the driver side, the rubber is a bit compressed. When passenger side UCA gets installed, you tend to leave it in place loose. Now if you take out the driver side UCA, cycle the suspension or move anything like the trac bar, roll the tires back or forth, etc.. you put the strain on the passenger side UCA. Now the driver side doesn't quite want to go to it's home. If you adjust this and install - it will be a degree or two off.

This would only be an issue with rubber UCA bushings. I have Savvy control arms, but still rocking the rubber upper bushings on the axel.

Working on rear axle, and I have a full set of Currie control arms (all Johnny Joints).