The rear Savvy control arms went in over the holidays. I'm still waiting on a part to rebuild the front set.
For excessive precision, I wrapped each arm with a 1/12 rotation scale. That was pointless for the upper control arms, which get set to whatever length they need to be, but useful for the lower control arms so I could adjust both sides the same amount.
It all came together pretty easily. I set the arms to the original stock length so they could slot in easily in place of the old Moog arms. Then I tweaked the two lowers and one upper to get the pinion angle where I wanted it. When I put the second upper control arm in, I set it to fit the space and biased the bolt to the same end of the hole in the control arm mount as the first upper control arm. I reconnected the sway bar while I was setting up the control arms to help keep the axle level.
I also wanted to make sure I didn't mess up the thrust angle for the rear axle. That's just me worrying about something because I haven't dealt with it before. So I figured out a way to measure thrust angle.
I clamped the angle bar that I use for front-end alignment to the rear disc and shot a laser level straight down the axis parallel to the disc. Then I measured the distance from the laser line to the center body mount on both sides. If you measure the width between the two discs (as you do when you're doing a front-end alignment), and you get the body mount width from the FSM, a little geometry will get you the thrust angle of the rear axle.
What I learned was that as long as you keep both lower control arms the same length, the thrust angle is going to be well within spec (assuming the frame and axle are straight!). So I didn't really need to sweat it that much. But playing with lasers is fun anyway.
used some steel strap just like
@k-huevo did to make brackets to attach the brake lines to the upper control arms. All I had to do was Dremel out the holes in the strap a little to fit the bolts. I'm not sure I can match Mr. Blaine's brute strength on the jam nuts, so I marked the jam nuts and control arms so I can tell if they loosen at all.
And that's where the fun started.
I still had a tiny bit of vibration left after the lift and the transfer case drop, and I figured that correctly aligning the rear pinion angle would help, but on the first test drive it was very clear that the vibes were much worse with the Savvy arms in. I played around with pinion angle a bit more, and even set the arms back to stock length, but nothing helped.
I thought some of the problem might be that the u-joints in the rear driveshaft had 130k miles on them, all at stock height. If they had wear from operating in the original range and I pushed them out of that range with the lift, they might be causing the vibrations. So I put in new Spicer u-joints. That helped a little, but not much.
That left me thinking that the vibes had been this bad all along, but that the Clevite bushings in the Moog control arms were doing a good job of isolating the vibrations. After all, rubber is good at that, and maybe the poly bushings in the JJs pass more of the vibration through. That's one more data point for the
discussion on whether control arm bushings affect NVH.
So, I figured I'd put in the MML that I had bought but not installed, which was an adventure. I had to learn that unless you lift the tub, the transmission runs into it and prevents you from getting the motor mounts to line back up. Until I went at it with a spiral Dremel bit, I had no idea how I was going to notch the fan shroud without taking it out. And then I found that with both the MML and transfer case drop in, the top of the valve cover just rubbed the firewall, which transmitted lots of engine vibrations into the steering wheel and dash. Reducing the transfer case drop to 3/4" fixed that.
And, in the end, the vibes are gone and I've moved my transfer case skid up a bit. I might even be able to move it up more, but I'll just have to play around with it later. Also, the net u-joint operating angles and cancellation for the rear drive shaft are good, so I'm happy with how that all worked out.
Front control arms go in as soon as Currie gets back from their holiday break and sends me the part I need.