Ok I agree I'd like for the uppers to allow for shorter than 18" adjustment. It would be nice if they started at the factory 17.5"
Had same issues. We ended up having to lengthen the lowers to get the sway links off the axle. They kept banging into it. And also the tire fully rubbed the rear pinch seam to the point it was going to pop the tire, we had to bend it in for clearance. Spring looks like your maybe worse. Im not understanding how they think a cv style driveshaft will cure that, in my opinion running the diff up too high allows it to over-wrap( spin upwards) its self upon hard acceleration. 1-3degrees below driveshaft angle would allow for more upward angle upon acceleration keeping the driveline “inline” while under load. Which in my opinion is ideal.Ok I agree I'd like for the uppers to allow for shorter than 18" adjustment. It would be nice if they started at the factory 17.5"
Synergys instructions that come with the upper arms indicate that they expect us to use a "cv" driveshaft meaning a double cardan style and not the factory rzeppa. I don't know much about rzeppas and my google-fu ain't workin for me. I have read that you don't want the rzeppa pointed directly at the rear output of the transfer case as the joint needs some range of motion to move the grease around to lubricate itself so don't treat it like its a double cardan shaft. Also read that the joints strength is the same throughout its designed range of motion. I've been trying to find what the acceptable rear pinion angle range is for a jl with a factory driveshaft with no luck. To me logically its a true cv joint shaft so it should not matter as long as its within the mechanical limits of the cv joint, boot, and the pinion bearing has sufficient lubrication so rear pinion angle may not matter? If anyone knows please clarify for me.
For reference I'm not using the 2 inch kit so our situations may not be comparable. This is what I have that should be relevant to comparison:
Synergy 2" front 2 door coils (1" 4 door)
Synergy 3" rear 2 door coils (2" 4 door)
Complete set of Synergy adjustable control arms front and rear
Rancho adjustable track bars front and rear
Synergy rear sway bar links and drop brackets
Factory shock brackets
Moved my rear factory sway bar links up front
Here is where I am currently at on arm length:
Uppers are at 18" shortest setting.
Lowers are at 20.5"
Rear tire is centered in the wheel well. I have 4" of clearance between the tire and body seam in the rear. I think this may be too far back(have not flexed it out yet to see clearance at full compression) as the tire will move rearward on compression.
Also the sway bar link is not perpendicular. I may shorten the lower arms to get the sway bar geometry closer. I'm using the factory lower shock mount and I had to adjust the sway bar links a bit tall to clear the shock bodys at my shocks full droop with the factory arms. That may no longer be the case with the longer rear control arms so I' may shorten them up as well if possible. As far as coil bow it's not bad. May try the recommended 20.25" LCA length.
Here is where I'm sitting on pinion angle.
I was also having trouble with coil height but figured out the issue when I put my lower control arms adjusted to 20.5" with the factory uppers still attached. The exaggerated unequal upper and lower control arm length made the rear suspension squat and I lost more rear height. Put the uppers on at 18" and gained more height than I had with all factory arms. The rear coils are now at advertised coil height if you subtract 1.5" for it not being a Rubicon. Synergy front coils seem to run tall. I'm at 4.5" front 4.5" rear suspension lift over my factory setup. I only lost 1/2" going from the 3" front coils to the 2" front coils.
I drove it about 70 miles like this yesterday. No vibes and drives well even better than before now that my caster is at 5.5 Degrees.
The double cardan shaft is not to fix coil bucket position/spring bow (you need coil wedges or correction pads for that). It's for running longer shocks and more droop/higher angles than the factory rzeppa driveshaft can handle. My rear shocks are 30.5" extended and the boots on the rzeppas are pretty close 1/8" maybe just eyeballing it to touching metal at full droop. This stuff was designed for a JK and as I understand it the rzeppas on the JK have a lower operating angle than the JL.
Makes sense for the drive shaft for the shocks. I was figuring a higher pinion angle on the rear would cause wear problems with regular driving with the torque of the engine to shaft causing the rotation to make the axle try to spin. But maybe not the case for links only leafs. Rock krawler calls for 2-3 degree difference of pinion to driveshaft with pinion being lower. Figured thats why
You should not be rotating your axle to make parts clear each other. That's not what adjustable control arms are for. If parts are hitting it sounds like something wasn't designed very well.
Yeah i know, thats why id like to see synergys rig. Mine looks perfect with my metalcloak arms. But my cousins with the synergys we could not get right. Had to take a hammer to his rig on the trail cuz the tires were getting cut by the pinch seam. And before we got to the trails we had to adjust the lowers longer because the sway links slammed into the axle hitting a drainage channel. Could run longer bumpstops i suppose but thats just hiding the problem in my opinion. Even with rk correction wedges in the rear, which helped, the passenger rear spring looks like an S and the driver like a C. If I had pictures id show, but hes out of town. You look at it and it doesnt look right. And its been aligned so spec wise its fine.
Only have a little over 300 miles on them and they are pretty good so far. They are quiet for mud terrains I'd say about average noise for an AT. Wet traction on highway is really good for MT's. Ride is kinda weird they feel smooth around town below 60 mph a lot like AT's I have run in the past. At freeway speeds they feel like your typical mt then above 80 and on up to 90 they are smooth as glass. I Might still have a less pronounced balance issue on one of the other tires. I swapped out for my spare as my right front was definitely out of balance. Still need to go get that one rebalanced and think I'll get the rest checked when I do.
