I am glad this thread is still alive, because I need some major help. I had noticed scuffs on my front diff (UCF), but didn't know enough to even know I had a problem until I started working on my front caster. Come to find out, I have all kinds of problems that need to be addressed.
Here is the situation; I have a 99" TJ with a D30, I installed an XJ tie rod, a UCF front diff cover and a Currie JJ track bar. My track bar hits the tie rod, the front diff cover and the diff at the frame side gusset. My tie rod hits the front of the diff cover and my track bar. I have adjustable control arms on stock mounts. My lower arms are set at 16" and my uppers are 15.25", which gives me 7* of caster and 1* of front pinion misalignment. I can dial all that in, but I my bigger concern is fixing the interference.
I have tried cycling the suspension every possible way in an effort to understand the dynamics of what is occurring. Here is the low down:
Scenario 1 - Setting the passenger side to ride height with wheels straight - raise the driver side = 3.75" of bump stop
* The frame side of the track bar at the lower JJ and the gusset hits the diff and is about to hit the front of the diff cover. If it cleared the gusset, there it would certainly interfere with the diff cover as the driver side came up more.
Looking down on the track bar from the wheel well
View from below
Turning the wheel full passenger pulls the track bar away from the front of the diff cover, but still interferes at the frame mount side. When I turn the wheel driver, the track bar is just kissing the front diff but stops, because the tie rod hits the driver side sway bar link mount.
Scenario 2: Full stretch - Set passenger all the way down and raise the driver side = 2.5" of bump stop before tire his fender, which is also when I run out of shock travel
* Turning full passenger, the tie rod hits the track bar with about a half inch before the tire hits my Currie anti-rock sway bar end links. No problems with the differential.
* Turning full driver, my tire rubs the back of the Metalcloak fender wall just as the tie rod connect with the sway bar link mount on the axle, No problems with the differential. I think a few degrees less caster and/or a 1" body lift will enable the tie rod to hit the sway bar link mount before the tire hits the fender. When I had the lower links at 16.25" there was a small gap between the tire and the rear fender wall at full stretch with the wheel full driver, but I had more interference.
* Removing the tire and shock, I can raise the driver side to 2.375" of bump stop until the tie rod hits the track bar and if I continue raising the axle, make it to 1.75" of bump before the track bar hits the diff at the frame side / gusset and it lifts the frame. Turning passenger binds the tie rod and track bar worse and going driver frees up the track bar, but the tie rod hits the front of the diff.
Scenario 4: Raise both wheels evenly
* The track bar hits the diff at the frame side mount at 4" of bump stop.
* Turning passenger binds the track bar with the tie rod and the track bar with the front diff cover
* Turning driver, I can go to about the same amount as before with the track bar free of the tie rod, however, the track bar hits the diff cover and the tie rod hits the sway bar end link mount on the axle.