We just finished an EVO coilover install on a 2008 JKUR. It's got 37's with ram assist and a draglink flip. We utilized some existing Teraflex bump stops (will most likely get swapped out later).
On a recent trip to the Winterfest 4x4 2017 in Hurricane, Utah, we found a couple of issues, one that is leading me to post this question.
First some background. This JKUR has had a full teraflex LCG long arm kit on it since 2010. We swapped the existing shocks and springs to the Evo coil overs and at the same time, did the drag link flip on it. It had been aligned and was driving very nicely prior to this work.
After the CO install, drive-ability was not impacted, it still drove nice, ride was better (as expected). From stock CO's we are set at 1" of preload in the rear and with 1" in the front we were a little light there (it just had an LS3 install) so we increased the front to 2" of preload as measured from the shock mount top to the near side of the preload ring. The rears were installed with a heavier spring and we have no issues on the rear.
I should also say that to meet the minum wheel width in the front, we had to go to 1.25 inch spacers with the raceline wheels that we have which have a backspace of 4.75 inches.
Ok, so here is the issue we are trying to understand how best to address.
At full flex the tires rub on the rear inside of the wheel wells (body). We have trimmed a little and yet, there was a couple of times at full flex where we rubbed pretty hard with the body on the inside top of the tire. Also at full flex, and full turn, we are rubbing the tire on the frame to the point where we have rubbed about 3 inches smooth. We don't hit any other place inside the front wheel well, so the bumpstops are doing their job.
On a recent alignment, the caster was set to 4.2 degrees, but I've noticed that the axle pucks and the frame bumpstops are not very aligned. At drive height, they are off by about 1/2 the puck diameter (approx hockey puck sized). I know that the axle pivots on the long arms and that it should be more forward the more compressed the suspension is, but I'm just wondering how I go about determining if with all the changes the axle has be positioned further aft than it might need to be. E.g. The CO's are almost exactly vertical when at parked ride height.
Is there any way to take a set of measurements to axle center that might tell us if we are in the ballpark or if we need to move the axle forward (which I'm assuming you'd do by adjusting both top and bottom control arms out). Or is this one of those get in line, everyone has this issue with larger tires, kind of things?
As it relates to the frame rubbing, I think this may have to do with the offset being too deep on the wheels...
Racelines don't have much availability with offset spacing and I think there was a compromise there when the wheels were ordered. While we accounted for some of that with spacers, it still probably isn't ideal. (this may also effect where the tires rub on the body).
Anyway, figured I'd see what opinions might be offered to help us identify if we have a wheel well, centering issue and how to address it?
Thanks in advance. If anyone wants a panoramic image for multiple monitors, you'll have to live with those jeeps in the image, but here you go... we are the 3rd from the left in the row
... - https://dl.dropboxusercontent.com/u/6730484/PANO_20170121_150016.jpg
On a recent trip to the Winterfest 4x4 2017 in Hurricane, Utah, we found a couple of issues, one that is leading me to post this question.
First some background. This JKUR has had a full teraflex LCG long arm kit on it since 2010. We swapped the existing shocks and springs to the Evo coil overs and at the same time, did the drag link flip on it. It had been aligned and was driving very nicely prior to this work.
After the CO install, drive-ability was not impacted, it still drove nice, ride was better (as expected). From stock CO's we are set at 1" of preload in the rear and with 1" in the front we were a little light there (it just had an LS3 install) so we increased the front to 2" of preload as measured from the shock mount top to the near side of the preload ring. The rears were installed with a heavier spring and we have no issues on the rear.
I should also say that to meet the minum wheel width in the front, we had to go to 1.25 inch spacers with the raceline wheels that we have which have a backspace of 4.75 inches.
Ok, so here is the issue we are trying to understand how best to address.
At full flex the tires rub on the rear inside of the wheel wells (body). We have trimmed a little and yet, there was a couple of times at full flex where we rubbed pretty hard with the body on the inside top of the tire. Also at full flex, and full turn, we are rubbing the tire on the frame to the point where we have rubbed about 3 inches smooth. We don't hit any other place inside the front wheel well, so the bumpstops are doing their job.
On a recent alignment, the caster was set to 4.2 degrees, but I've noticed that the axle pucks and the frame bumpstops are not very aligned. At drive height, they are off by about 1/2 the puck diameter (approx hockey puck sized). I know that the axle pivots on the long arms and that it should be more forward the more compressed the suspension is, but I'm just wondering how I go about determining if with all the changes the axle has be positioned further aft than it might need to be. E.g. The CO's are almost exactly vertical when at parked ride height.
Is there any way to take a set of measurements to axle center that might tell us if we are in the ballpark or if we need to move the axle forward (which I'm assuming you'd do by adjusting both top and bottom control arms out). Or is this one of those get in line, everyone has this issue with larger tires, kind of things?
As it relates to the frame rubbing, I think this may have to do with the offset being too deep on the wheels...
Racelines don't have much availability with offset spacing and I think there was a compromise there when the wheels were ordered. While we accounted for some of that with spacers, it still probably isn't ideal. (this may also effect where the tires rub on the body).
Anyway, figured I'd see what opinions might be offered to help us identify if we have a wheel well, centering issue and how to address it?
Thanks in advance. If anyone wants a panoramic image for multiple monitors, you'll have to live with those jeeps in the image, but here you go... we are the 3rd from the left in the row
... - https://dl.dropboxusercontent.com/u/6730484/PANO_20170121_150016.jpg
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