Editing Z31/reartailconversion php (section)

== Replacing Your Z31 Power Window Motor ==

With the rounded '87 style front end and a cleaner appearance thanks to the lack of bulky side molding, the '84-'86 rear started to look dated and out of place. So, why not update it? After considering several options, I decided the most appropriate (for a 200ZR-II replica) would be to swap to the more modern '87+ rear panel. When looking at both cars side by side, the challenge—and the payoff—of this project becomes clear.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/85rear.png 1985 Z31 Rear]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/87-89rear.png 1987-89 Z31 Rear]

=== Items Needed ===

If you plan to install an '87 panel onto your pre-'87 ZX, you’ll need to acquire the rear panel. You can order it new from Nissan (part number [https://www.nissanpartsdeal.com/parts/nissan-panel-assy-rear~79110-21p50.html?vin=&make=Nissan&model=300ZX&year=1984&submodel=&extra1=&extra2=&filter=( 79110-21P50])), or have a local salvage yard cut one from an existing '87-'89 chassis. For my conversion, Cuda from [http://www.z31.com Z31.com] sent me a rear panel from his '87 parts car, saving time and money. The following approach uses a rear-panel cut.

=== Procedure ===

==== The Process ====

Start by welding in a stabilizer bar in the rear hatch area, just behind the quarter windows. This keeps the chassis from flexing outward after the original rear panel is removed.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion1.jpg Stabilizer Bar Welded]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion2.jpg Rear Panel Prep]

The rear panel is held with a series of spot welds. Begin by drilling out the welds on the upper edge (where the hatch closes). The '84 latch and structure will be reused, so drill out its welds as well. Use a 3/8" cobalt bit and only drill through the first layer.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion3.jpg Drilling Spot Welds]

'''Note:''' Mark weld locations with paint before drilling for easier removal.

Once the spot welds are drilled, separate the panels using a screwdriver. Don’t worry about damaging the panel you’re removing.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion4.jpg Panel Separation]

Continue drilling and separating spot welds on the outer edges and license plate panel.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion5.jpg Outer Edge Welds]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion6.jpg License Panel Removal]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion7.jpg License Panel Welds]

For the lower edge, cut the panel approximately 2" above the factory seam.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion10.jpg Lower Edge Cut]

At the quarter panels, cut about an inch from the edge, leaving all quarter-panel to tail-lamp mounts intact. Remove the panel from the vehicle.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion11.jpg Quarter Panel Cuts]

Here’s a comparison of the original (removed) panel and the '87 panel.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion13.jpg Old vs New Rear Panel]

To install the '87 panel, trim the quarter panel areas to fit the '84 section. Trim a little at a time and test fit until perfect. Below are examples of what I trimmed:

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion8.jpg Driver Side Trim]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion9.jpg Passenger Side Trim]

Remove inside support structures and the latch (spot-welded in place). Drill out spot welds just as before.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion12.jpg Support Structure Removal]

Prep the panel by carefully fitting and trimming until the new panel fits perfectly.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion20.jpg Test Fit 1]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion21.jpg Test Fit 2]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion23.jpg Test Fit 3]

Before welding, test fit the taillamps to ensure even spacing.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/rearconversion24.jpg Test Fit Taillamps]

Once satisfied, weld the panel in place. Plug weld to the upper reinforcement and latch using the drilled holes, and run continuous welds at the quarter panels and along the bottom. The '84 lower inside edge may need to be bent to fit the '87 panel.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/tailprogress1.jpg Welded Panel]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/tailprogress3.jpg Weld Progress]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/tailprogress4.jpg Panel Welded]

Grind welds smooth and shape the area with high-quality filler. There is a continuous stitch weld along the bottom. (Note: Filler in the quarter panel here was for accident repair, not tail conversion.)

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/tailprogress20.jpg Filler Applied]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/tailprogress30.jpg Filler Sanded]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/tailprogress40.jpg Panel Shaped]

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/tailprogress50.jpg Panel Sanded]

Finally, prime and paint the rear section. Apply 3M's Brushable Seam Sealer to all welds inside and out before priming. Ensure all interior seams are coated to prevent moisture intrusion. Mask the body to prevent paint from getting inside.

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/maskedforbed.jpg Masked for Painting]

Prime with a high-build surfacer and sand to 600 grit (or as instructed by the primer manufacturer).

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/finalsand4.jpg Final Sanding]

Finish with your chosen paint, install lights, hatch seal, and closers. If desired, add the '87 rear emblem (I chose the graphite "300zx Turbo" — [http://www.courtesyparts.com/betasite/label-rear-p-506830.html part number 99099-21P11]).

![https://dev.z31library.com/xenonzcar_archive/z31/images/Raredare1/Rear%20Conversion/102803_3.jpg Finished Rear Conversion]

=== Sources Used ===

[[Z31/z31fsm php|1984-1988 Nissan 300ZX Factory Service Manual]]
* Images and write-up By: Redare

[[Category:Imported from Xenonzcar]]