Jeep Wrangler Forum banner
  • Hey everyone! Enter your ride HERE to be a part of September's Ride of the Month Challenge!
1 - 18 of 18 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Hey everyone tia for any help.
I have a 2012 jku I've been in touch with RC and identified my lift as a 3.5" my question is it has def sagged a bit and might be 2" now, can I go with bigger coils in the rear like 4" MC or other quality coils with the RC lift. In essence just swapping out the rear coils and shocks? I eventually will do the front as well but the back is creating an issue with 37" tire's scrubbing the front of the well on big dips. The front has plenty of clearance. Also just a little more info the jeep has heavy steel stinger bumper, winch , Carrier in the rear.
Also can anyone tell me from the pic of rear coil if and how bad it's sagging if at all and suggestions of best coils,shocks for a soft ride. I don't mind bounce in fact I prefer that to rigid. Thank you!
Tire Wheel Automotive parking light Land vehicle Car
Tire Wheel Automotive tire Vehicle Motor vehicle

Thank you.
4518708
4518709
 

·
Super Moderator
Joined
·
13,331 Posts
Welcome to the Forum Mays big toy,

I moved your thread here. The posters here should be able to help you out.

Good Luck, L.M.
 

·
Super Moderator
Joined
·
7,363 Posts
While RC lifts aren’t very good, and you may have some sagging, you should not have issues with tires rubbing if you have the correct amount of bumpstop extensions for your tire size. Sagging aside, the tires should not rub when the suspension compresses. You need to figure out why it is rubbing and correct that. You may need additional bumpstop, or you may need to better center the tires in the wheel wells. Or both.
Once you resolve the issue of the tires rubbing, you may want to upgrade the springs. MC springs are nice, but I would suggest 3.5” springs and doing the full set. MC springs tend to over deliver, so 3.5” springs will likely deliver 4” or so of lift.
If going with the MC springs, I would suggest spending a little more and getting the matching MC RockSport shocks.
 

·
Premium Member
Joined
·
2,157 Posts
Welcome May

You mentioned 37’s
Was that a typo? They don’t look like 37’s in the pic.
Especially with rubicon wheels
 

·
Registered
Joined
·
161 Posts
Here's my experience. Bought a 2009 JK Wrangler 2 door used last fall. It had a new RC 3-1/2" lift and inner fenders. etc etc. I started hearing a clunk in the rear on dips at speed, and other things. I looked and looked for a few weeks and finally found it. The track bar bracket was hitting the frame. Called RC and they said "oh you need spacers" So I bought spacers. They barely fit. Went to Moab. Clunk still there and now the rear springs are binding. Got back home, Bought a Metal Cloak lift and tossed the RC.. IMO RC is JUNK!
 

·
Registered
Joined
·
654 Posts
Unless you really have experience dialing in a Jeeps suspension, (or any vehicle) I wouldn't mismatch spring heights nor piece various manufacturers ifts together without knowing I had the time and money to play trial and error. If you got it like that, by all means, give us an update as you go along.

I believe most JK owners trim the body to accommodate a larger diameter tire @The rear. Jeep eliminated that pinch seam at some point after 2013 or 14, I believe.

Someone correct me if Im wrong, but what you should actually be adding is adjustable control arms back there to get the wheel centered in the well, thus additionally adding an aftermarket driveshaft too.
 

·
Super Moderator
Joined
·
16,560 Posts
It's common to need to trim the Rubi rail in the back to fit 37's. I suspect that is what you are rubbing.


As mentioned above, do not mix and match springs... Buy a set. I suggest the AEV spring set. But, you also should buy new shocks and a front and rear bump stop kit because RC doesn't include any. Bad juju for the shocks...

 

·
Registered
Joined
·
7,352 Posts
Someone correct me if Im wrong, but what you should actually be adding is adjustable control arms back there to get the wheel centered in the well, thus additionally adding an aftermarket driveshaft too.
That’s a slippery slope. When you push the axle back you have to trim the rear pinch seam too. You also take the chance of over extending your rear driveshaft.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
654 Posts
That’s a slippery slope. When you push the axle back you have to trim the rear pinch seam too. You also take the chance of over extending your rear driveshaft.


Sent from my iPhone using Tapatalk
Well, correct. That why I stated you'd need an aftermarket driveshaft. But centering the wheel isn't quite stretching the Jeep. You'd be bringing the wheel back to center of the well. But what the hell do I know? Id take it to a reputable shop if it were me, tbh. Cutting the well is what I believe most people do.

One of my buddies added 38" tires on his JKU and did have to do shyt. He's got a 3" lift.
 

·
Super Moderator
Joined
·
16,560 Posts
That’s a slippery slope. When you push the axle back you have to trim the rear pinch seam too. You also take the chance of over extending your rear driveshaft.


Sent from my iPhone using Tapatalk
Well, correct. That why I stated you'd need an aftermarket driveshaft. But centering the wheel isn't quite stretching the Jeep. You'd be bringing the wheel back to center of the well. But what the hell do I know? Id take it to a reputable shop if it were me, tbh. Cutting the well is what I believe most people do.

One of my buddies added 38" tires on his JKU and did have to do shyt. He's got a 3" lift.
The biggest problem is that the rear arms move the axle on an arc. The more lift, the farther it swings forward. But as you compress the suspension it moves back in to the center of the wheel well. When you lengthen the control arms, now the axle swings further back as you compress the suspension and a new set of problems comes in. There is a little room to work with, but not a bunch. Up to 3.5, we usually just add adjustable uppers to set pinion angle. That gives you a little more wheelbase, but it's not significant.
 
  • Like
Reactions: fourpointzero

·
Super Moderator
Joined
·
7,363 Posts
But wait, there’s more.
The drive shaft extends when the suspension compresses and shortens when the suspension droops.
I think that is opposite what most people expect. But it does that because the control arms are shorter than the drive shaft.
Adding bumpstop extensions changes both the maximum extension of the drive shaft (reducing it) and how far back the axle will go when the suspension compresses (again, reducing it).
 

·
Registered
Joined
·
654 Posts
I stand corrected. I'm aware of the arch / movement of the axle, but Im thinking a **** hair of adjustment. Then again, Ive never "corrected" or tried to clear the wheel well openings on any of my Jeeps, so yah, I cannot give for certain a solution.

No one can confirm, though if the later JK's had that seam cropped from the factory? I swore I read and saw photos of that, here on the forum.
 

·
Super Moderator
Joined
·
7,363 Posts
I stand corrected. I'm aware of the arch / movement of the axle, but Im thinking a **** hair of adjustment. Then again, Ive never "corrected" or tried to clear the wheel well openings on any of my Jeeps, so yah, I cannot give for certain a solution.

No one can confirm, though if the later JK's had that seam cropped from the factory? I swore I read and saw photos of that, here on the forum.
The front side of the rear pinch seam is “trimmed” by the factory on the newer Jk’s. So often all you have to worry about is the rock rails if so equipped.
The pinch seam is still there, but it is reprofiled for better clearance.
 

·
Registered
2015 Anvil JKUR Hard Rock.
Joined
·
428 Posts
I stand corrected. I'm aware of the arch / movement of the axle, but Im thinking a **** hair of adjustment. Then again, Ive never "corrected" or tried to clear the wheel well openings on any of my Jeeps, so yah, I cannot give for certain a solution.

No one can confirm, though if the later JK's had that seam cropped from the factory? I swore I read and saw photos of that, here on the forum.
Pinch seams are factory trimmed on my 15 ruby. I trimmed the rock rails. Happened around 2013???
Tire Wheel Automotive tire Vehicle Tread
 
1 - 18 of 18 Posts
Top