Overview

This is how I put WJ rear seats into my XJ. I tried to maximize legroom and headroom. I re-used stock XJ mount points and seat belts for maximum strength and safety, and drilled only 2 holes through the XJ floor, neither of which are near frame rails.

This is NOT a bolt-in afternoon swap. Expect lots of measuring, marking, cutting, bending, drilling, and test-fitting. Plan to spend at least 8 solid uniterrupted hours.

How This Install Differs from Others

Most Important:

• Seat-backs are mounted using pre-existing XJ mount points
• Seat-back center bracket is fabricated instead of using the WJ bracket
• Seat-bottoms are mounted for maximum legroom and headroom
• Seat-bottoms fit snugly against the seat-backs

Less Important:

• No drilling holes near frame rails
• No cutting or bending the XJ floor or fender-wells

Parts List

--- From a Donor WJ ---

• Rear seat backs
• Rear seat bottoms with hinge brackets
• Do NOT need the center seat-back bracket
• Do NOT need the seat-latch plates
• Do NOT need any mounting screws or nuts

--- From a Hardware Store ---

• Qty 2: M10-1.5 x 40mm bolts (for fender-well anchor mount points)
• Qty ?: M10 Washers to make two approx 5/8" spacers (for fender-well anchor)
• Qty 11: 1/4-20 x 1" bolts, fender-washers & nylock nuts (3 for center bracket, 8 for seat-bottoms)
• Qty 1: 3/8" threaded lamp tube plus 2 locking nuts (for center bracket pivot)
• Qty 2: #? x ?" machine screw, nylock nut, 3/8" spacer, washers
• Qty 1: 5" T-bracket (to bend into a center bracket)

--- Tools ---

• Metric & SAE sockets & box wrenches as necessary
• T-?? Torx socket (to remove seat-belt bolt)
• T-?? Torx socket (to remove seat-bottom latch assembly)
• Socket Extenders
• Saws-all with metal blade (or hacksaw if you have muscle)
• Vice to hold metal brackets
• Hammer (4lb sledge preferred) to bend metal brackets
• Drill & metal drill-bits in sizes: 1/4", 7/16" (or 13/32"), 1/2"
• Locktite (superglue might work)
• Measuring tapes & rulers
• Permanent marker
• Sharp knife (box cutter) for cutting carpet

Install Procedure

--- Prep --- Take everything apart
Take those WJ seat covers off and wash them. Trust me. You will be shocked at the filth that comes out. I washed my covers by hand in a tub sink with laundry detergent. Now my XJ smells like a laundromat. Remove stock XJ rear seat, brackets, mounting bolts, etc. Also remove the lower seat belt anchors (T-?? socket). Remove rear carpet - helpful but not required. My rear carpet was out and it made measuring & marking easy.
--- Mount the Seat-Backs --- The WJ seat-back brackets will be cut, drilled, and bent to allow them to be mounted to the XJ wheel-well anchor and the seat-belt anchor.
Cut the carpet away in the area where the WJ seat-back bracket meets the fender-well. If you don't do this, the carpet will bind when the brackets are tightened down. Remove, cut, and re-install the XJ sheet-metal seat supports. Cut off the smaller section closer to the fender well. This allows the WJ seat-back brackets fit next to the fender mount. Place the WJ seat-backs & mark the center of the fender-well anchor. For positioning purposes only, line up the seat bracket slot with the seat belt anchor hole (only to get alignment correct; the slot will NOT be used to mount the bracket). With the slot aligned to the anchor hole, mark the side of the seat bracket for the center fender-well anchor. Drill out the hole you marked on the side of the bracket for an M10-1.5 bolt. The hole can be as small as 13/32", but an even 1/2" will give wiggle room for adjustment. Loosely mount the WJ seat-back into the fender-well anchor using an M10-1.5 x 40mm bolt. Mark the seat-belt anchor hole location on the bracket. Cut the vertical part of the WJ seat-back bracket 3/4" rearward from the seat-belt anchor location mark. Bend & hammer the vertical portion of the WJ seat-back bracket flat. This will be the mounting surface for the seat-belt anchor bolt. Space the WJ seat-back bracket about 5/8" from the fender-well anchor point (using washers) and snugly mount it to the fender-well anchor. The WJ seat-backs need to be spaced about 5/8" from the fender wells for 2 reasons: A.) to take up the gap between the seat-back halves, and B.) to clear the interior panel behind the door. Mark the the seat-belt anchor hole on the newly-bent-flat portion of the WJ seat bracket. This is difficult. I recommend looking at your mark from several angles to make sure it's in the right spot. Remove the WJ seat-back and at your mark drill a 1/2" hole for the seat-belt anchor. Repeat steps 1-9 for the other seat-back half.

--- Fabricate & Install the Seat-Back Center Pivot Bracket ---

A seat-back center-pivot bracket will be fabricated by bending a standard 5" T-bracket so the "post" of the T sticks upward, and the "cross" of the T is mounted to the floor. A floor-plug is directly below & behind where the seat-backs meet. The bracket will be bent to avoid this plug.

1. Install both seat-backs and measure the distance between the metal floor and the center of the seat-back pivot holes. You will want to support the under-side of the seat-back so they are level and don't "droop". Use shop rags, stack of magazines, wood shims, etc. I had the carpet out so this was easy. If your carpet is in, cut a slit in the carpet so a small ruler can be inserted all the way to the metal floor. It is possible to measure from the carpet instead of the metal floor and mount your bracket on top of the carpet. But be warned - the carpet will compress as you tighten the bracket and throw off your measurements! My floor-to-seat-pivot measurement came out to about ??"
2. Take your measurement from the previous step. **SUBTRACT the thickness of the T-bracket.**
3. Measure downward by the amount above from the center of the first hole on the post of the T. Bend the bracket 90 degrees at that location. The first hole on the post of the T will be drilled out to hold threaded rod used as the seat-back pivot. The post of the T must be bent at the correct location so that when the cross of the T is mounted to the floor, the pivot is the correct height above the floor. If your bend isn't exact, remember that it's easy to shim the entire bracket upward.
4. Drill out the pivot hole to 13/32" to hold the threaded lamp-rod that will be used as a pivot axle.
5. Cut ??" off the bracket above the pivot hole. This part would otherwise stick up above the seat-backs when they're folded flat.
6. Place the bracket in-line with the seat-backs pivot holes and mark the drill locations to mount the bracket to the floor.
7. Also mark the spot where the bracket overlaps the floor well under the seat. Bend this part down so it is flush with the floor.
8. Cut ??" of lamp tube to be used as the pivot axle. Center this in the bracket and install with a locking nut on each side. Use locktite so it won't come loose!
9. Once satisfied with your center-pivot bracket, install it between the seat-backs and mount it to the floor. If your bracket is like mine, it will clear the plug on the floor and will mount cleanly under the vehicle. Use fender washers and nylock nuts under the vehicle. I recommend using stainless hardware for this bracket so it won't rust under the vehicle and become difficult to remove!
10. Finalize the seat-backs by mounting them to the fender-well and seat-belt anchor points. Use lock-tite at least on the seat-belt anchor bolt, but both mounting points would benefit from lock-tite.

--- Modify & Mount the Seat Bottoms ---

The seat bottom plastic and foam must be significantly trimmed to fit between the wheel wells.

1. Remove the cover & foam from the seat bottoms and remove the metal latch mechanism (4 bolts, T-?? socket). The WJ latch system will NOT be used. The seat bottom plastic will be trimmed where the metal latch mechanism is located. I'm telling you, you're going to want to wash those seat covers since they're off already.
2. Place the seat-bottoms in the vertical position and the seat brackets flush against the XJ rear foot-well vertical riser. Leave about 1/4" gap between the seat bottoms. Center the seat bottoms to clear the door frames equally. Mount the bracket to the vertical riser. This will give as much legroom as possible. Position the brackets as low as possible on the riser. This will give you as much headroom as possible. I cut the carpet below the brackets so the brackets are a little further down.
3. Mark the top of the tear-drop-shaped holes in the bracket. These will be used to mount the seat-bottom.
4. Drill a 1/4" hole through the marks. Use 1/4-20 bolts, fender washers, and nuts, to snugly mount the seat bottom brackets. Note that there is a wiring harness directly behind the vertical riser. Be careful and don't drill into that!
5. Pivot the seat-bottoms down and note where they hit the fender well. Use a hacksaw blade or saws-all to cut the plastic material that hits the wheel wells. Keep about 1/4" clearance between the seat-bottom plastic and the wheel well. Repeat until the seat bottoms completely clear the fender wells and fold into the horizontal position.
6. Position the seat foam on the plastic and note where the foam hits the wheel well when the seat-bottom is pivoted into the horizontal position. Using a hacksaw blade or knife, carefully cut away the foam until it snugly fits against the wheel well.
7. The WJ seat latches stop the seat-bottoms from flexing side-to-side under load. Those latches are not used in the XJ, so the seat-bottoms will flex. (Optionally) install a "peg" in the seat-bottom that secures it to the sheet metal bracket under the carpet below the seat: Place a mark ??" from the fender well on the rear lip of the plastic seat bottom. This area overlaps the sheet metal brackets. Carefully drill a ??" hole through the seat-bottom plastic and through the bracket below it. Don't also drill through the floor! Pivot the seat-bottom to the vertical position and enlarge the hole in the sheet metal bracket to 7/16". Install #?? screw, fender washer, and 3/8" spacer into the seat-bottom plastic. The 3/8" spacer will align with the 7/16" hole in the bracket and stop the seat-bottom from flexing and twisting.
8. Mark & drill 1/4" holes through the vertical riser to mount an additional 1/4"-20 bolt through the lower bracket holes. Don't mount the seat-bottoms tightly because the seat covers must be re-installed!
9. (Optional) Cut the passenger-side (larger) seat-bottom to clear the driveshaft tunnel and completely pivot up: Mark ??" from the front lip of the seat-bottom's center section. Cut away that section. Place the seat-bottom foam on the plastic seat-bottom and cut the foam to match the plastic.
10. Re-install the seat-bottom covers. Last chance man. Wash those seat covers. They're nasty. It's probably easier to remove the seat-bottoms out of the vehicle to do this. The seat covers will be loose in the areas where the plastic and foam are cut. They can be cut, re-stitched, or simply fastened to the seat-bottom.

And you're done! Pop a cold one and admire your work. Now your XJ has the finest 2004 headrest and split-rear-seat technology that money can buy.