Sagging Liftgate

Ok, so I have a 96 xj with the ultra-sweet fiberglass liftagate. The problem is, it has now started to sag and the bottom of the liftgate is rubbing on the body. Beside making a most anoying squeak, it also starting to wear away the fiberglass gate itself. What do I do to fix this? Is there an easy way to adjust the gate? Thanks for any help.

After you posted this I looked at mine and it appears it also is sagging a bit ...

The FSM decribes the rear liftgate hinges being adjustable using shims.

The pics indicate the shims are unique for this application ... and are slotted so they can be removed/added without removing the hinges.

The liftgate can be adjusted upward/downward and inward/outward.

One of mine had the same problem. I added some shims and it worked fine. It's easy enough to make your own shims.