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Center Driveshaft Modification Crawl Box and Transfer Case Installation Crawl Box Shift Box Removal Disassembly Installing Crawl Box onto Transfer Case Materials Recommended Materials Required Notes Pre-Installation Checks Tools Recommended Transfer Case Shifter Modification Vehicle Modifications

Color Codes Parts included in kit (blue): (please see attached parts list) Drawings and photos (cyan) Cautions and important points (red) Materials required (green) Note:  You can click on the text mentioning a photo or drawing and you will see the corresponding picture or drawing. Tools required: Jack and jack stands, or lift (to support Samurai while working underneath) Standard and Phillips screwdrivers Metric wrenches and sockets Magic Marker or equivalent Torch suitable for heating 1/2" diameter steel bar Bench vise, solidly mounted Feeler gauge set Electric drill and bits 3/16" roll pin punch (looks like a regular drift punch, but has a centering tit on the tip) Snap ring pliers Soft mallet Tools recommended:   Transmission jack (or strong helpers) (to lift transfer case and Crawl Box into place) Tripod-type stand, adjustable height (to support tail end of transmission) Reciprocating saw with 32 teeth-per-inch metal cutting blades Die grinder or equivalent with 1/4" diameter carbide rotary burr and abrasive cut-off discs   Materials required (green):     1988 and earlier Suzuki Samurai U-joint yoke with flange only if you have a 1990-up Samurai (you can use the one from the aft end of the center drive shaft, or from either end of the front or rear drive shafts. Required because of tight clearance at aft end of transmission) RTV sealant Medium-strength thread-locking sealant (example: Loctite Blue) Extreme-pressure, water-resistant grease (example: boat-trailer wheel bearing grease) Oil (to replace your transfer case oil when you drain it)(1.7 pts 85W90 per factory) Gear oil for Crawl Box (Redline Synthetic 85W90 recommended) Spray paint Duct tape Parts cleaning solvent Materials recommended:     New Suzuki center drive shaft U-joint part number 2720083812 (current as of May 2000). Notes:     As is normal for jobs of this importance, we request that, before you get started, you read through these notes, look at the parts mentioned, and obtain all tools and supplies. Please feel free to call us at (800) 222-3619 or (818) 503-8100 if you have any questions or concerns. Keep all parts and fasteners you remove separated by the location you removed them from, until installation is completed. Clean all parts and fastener threads before re-assembly. Examine for wear or damage. Replace as required. While installing our kit, we strongly advise reinforcing your existing transfer case mounting brackets. Our customers report that they tend to flex even under normal off-road usage. Since you will be removing them anyway, now would be a good time. Steps:       A. Disassembly   Remove your driver and passenger seats: 4 bolts each, at front and rear of seat rails. Remove your transmission and transfer case shift knobs and boot surround trim. Remove your carpet around the central tunnel. Remove your transmission and transfer case shift boots. Raise your Samurai and support it securely. Make sure one person can work safely under it while someone else is inside the passenger compartment helping. Remove your exhaust system from transmission rearward as required. Remove your front, center, and rear drive shafts. Keep the fasteners for re-installation. Drain your transfer case. Disconnect the wiring at your transfer case. Unscrew the retaining fastener and remove the speedometer cable from the aft end of your transfer case. Remove your shift lever from your transfer case: push the retaining cup in, rotate counter-clockwise, allow the spring inside to push the cup out, and then pull the shift lever directly out. Remove your transfer case. Unclamp the wire harness inside transmission tunnel on the drivers side, and pull it away from the sheet-metal. B. Vehicle Modification Locate the frame brackets which support the transfer case. Extend (slot) these holes as far as you can towards the drivers side, without breaking through the end of the brackets. (This distance should be approximately 3/4".) We suggest using an air-operated die-grinder with a 1/4" diameter carbide burr and stick wax for lubrication/release of chips. Wear eye protection! Mark and cut the drivers side seat support structure per drawing A and photos 1 and 2 shown below. Make sure you keep the indicated amount of metal around the seat mount bolt hole. We suggest using a reciprocating saw with a 32 teeth-per-inch metal-cutting saw blade and/or a die grinder with an abrasive cut-off disc. Drill out all spot welds holding the portion of the support structure closest to the transmission tunnel. Remove the section marked "X" in the photos and discard it.   Photo 1 Photo 2 Position Drivers Side and Top Cover Panels. Check their fit and trim as desired. We have found significant dimensional differences from one Samurai body to another, so you may need to massage our panels (with a soft mallet) to fit yours exactly. Mark the floor around their periphery with a Magic Marker or equivalent. Remove the Drivers Side and Top Cover Panels.   Remove asphalt sound dampening on floor and tunnel within the marked area. (We found it easiest to chip it away with a chisel or dead screwdriver when temperature is cold.)   Mark the center tunnel and drivers side floor per drawing B below. Also, mark a 3" long x 3" tall (starting at the floor) area on the passenger side of the center tunnel per drawing B to clear your Transfer Case shift lever. Please see photos 3, 4, and 5 below. The area between these lines and the lines made in step 12 is for overlap between your original sheet metal and our replacement panels. The #6 x 1/4" sheet-metal screws will go through both pieces in this zone. Photo 3 Photo 4 Photo 5 Cut away center section of tunnel on your inner line. Do not cut wiring inside tunnel.  Heat and bulge out by 1/2" the 3" x 3" area from step 14. Alternatively, you may also cut that area away completely if you wish: our Top Cover Panel will cover the opening.        C. Center Drive Shaft Modification    Disassemble your central drive shaft (see photo 6 below) using snap ring pliers and a vice or press. Build a new assembly consisting of 3 of the 5 pieces: (1) the front slip-yoke section (the part that fits into the transmission), and (2) the rear flanged yoke section (the part that attached to the input flange of your transfer case) with a U-joint (3) connecting them (use a new U-joint if neither of the ones you just removed are in good condition). The tubular section of your original center drive shaft, and one of the two U-joints, will not be needed. Photo 6 Attach our Input Slip Flange to the assembly you just built using 4 each 8mm-1.25x40 hex head bolts, 8mm washers, 8mm lock washers, and 8mm-1.25 nuts. Verify that you have a straight shot access to the 1/8" NPT grease fitting. If you don't, rotate the fitting until you do, or replace it with the supplied 1/8" pipe plug if you choose. The head of the bolts should be forward so that the part of the bolt in shear (at the joint between the drive shaft flange and our Input Slip Flange) is the unthreaded section. Also, align the flats of the bolt heat parallel to the circumference of the Input Slip Flange. (There are two different hole patterns on our flange, one for 8mm fasteners for Samurais up to 1988, and one for 10mm fasteners for 1990 and later. Ignore the larger hole pattern.) Apply grease to the external splines of this assembly. Coat the ends of the Compression Spring with grease and drop it into the input end of your new assembly (the grease is to keep it straight during installation). Set the assembly aside for later installation.     D. Transfer Case Shift Lever Modification   Heat and re-bend your transfer case shift lever per drawing C and photos 7, 8 and 9. In the photos, the stock transfer case is on the right, the modified one is on the left. Make sure the clocking (axial orientation) of the end that goes into your Transfer Case matches our drawing and photos. Repaint and set aside for later installation.     Photo 7 Photo 8 Photo 9   E. Crawl Box Shift Box Removal   Remove the Vent Tube Barb Fitting from the side of the Crawl Box Shift Box. Set aside for later re-installation. Remove the Pipe Plug on the opposite side of the Crawl Box Shift Box. Set aside for later re-installation. Remove the Lock Nut and Detent Pin on the side of the Crawl Box Shift Box. Set aside for later re-installation.  Remove the Hairpin Clip, Clevis Pin, Washers, and Bushings at the Crawl Box Shift Box pivot point. Set aside for later re-installation. Pull the Direct Shift Lever away from the Direct Shift Box Cover. Remove 4 1/4-20x2" socket head cap screws holding the Direct Shift Box Cover in place. Set the Direct Shift Box Cover and attached parts aside for later re-installation. Reinstall the 4 1/4-20x2"socket head cap screws to hold the Crawl Box Shift Box in place. Use washers totaling 1/4" thick under their heads to simulate the thickness of the Direct Shift Box Cover. Look into the Crawl Box Shift Box. You will see a 3/16" roll pin going cross-way through the Shift Fork and the Shift Rod. Position this pin in line with the holes on either side of the Crawl Box Shift Box (where the Vent Tube Barb Fitting and Pipe Plug were) by pulling or pushing on the Shift Rod.   Lay the Crawl Box on its side with a wood block under the Crawl Box Shift Box. Drive out the 3/16" roll pin with a 3/16" roll pin punch. Set aside for later re-installation.  Pull the Shift Rod forward and out of the Shift Fork.   Remove the 4 1/4-20x2" socket head cap screws holding the Direct Shift Box in place. Set them and the Direct Shift Box aside for later re-installation. Put duct tape or equivalent over opening in Crawl Box to keep debris out during installation.     F. Installing Crawl Box onto Transfer Case   Clean the front face of your transfer case input flange. Apply RTV sealant around raised boss. Place our Output Slip Flange on your transfer case input flange, matching  hole patterns. (There are two different hole patterns on our flange, one for 8mm fasteners for Samurais up to 1988, and one for 10mm fasteners for 1990 and later.) Install the nuts, bolts, and lock washers which were originally used at this location to attach your central drive shaft. See photos 10 and 11 below. Photo 10 Photo 11 Verify that the two notches on the transfer case shift rails are in line with each other. You can see them by looking down the hole where the shift lever sits. Remove the existing fasteners holding your transfer case halves together at the 6 places where our Adapter attaches. You will not need these. Clean out the threads in the case halves. Install our Adapter using 6 each 8mm-1.25x130mm socket head cap screws and 8mm lock washers loosely tightened. Check with a feeler gage to see that no gap exceeding 0.005 exists between our Adapter and your transfer case at any of the 6 attach / support points. Remove the fasteners. (If you do find a gap, we suggest you either make some shim washers from shim stock, or use a metal-filled epoxy as a liquid shim.) Reinstall the fasteners loosely with thread-locking sealant. Place our supplied Alignment Tool over the shaft of our Output Slip Flange and move the Adapter around until the Alignment Tool fits inside the bore of the Adapter. Please see photo 12 below. The objective is to have the raised boss on the forward face of our Adapter centered - relative to our Output Slip Flange - to within 0.010. Tighten all 6 fasteners evenly, making sure the Alignment Tool does not bind up. Let thread sealant set. Remove and save the Alignment Tool.   Photo 12 Place the Crawl Box carefully onto our Output Slip Flange so as not to damage the Crawl Box's' output end lip seal. Orient the Crawl Box so that, with the transfer case positioned as it will be in the vehicle, the Crawl Box Shift Box is at the 1:00 o'clock position, looking forward.) Attach the Crawl Box to the Adapter using 5 each 3/8-16 nuts, lock washers, and washers. Please see photos 13, 14 and 15. below. Please note that we shipped your Crawl Box with the Front Mount already installed. Photo 13 Photo 14 Photo 15       G. Pre-Installation Checks   Test fit your modified transfer case shift lever to insure that it clears our Adapter in all shift positions. Remove when done. Reinstall your transfer case mounting brackets to your transfer case to verify clearance. Remove material as required from the forward edge of the drivers side mount.      H. Crawl Box and Transfer Case Installation   Support the tail end of the transmission. Remove the transmission mount and isolator. Remove the isolator from the cast iron transmission mount. (The transmission mount will not be used.) Lift the assembled transfer case, Adapter, Crawl Box, and Front Mount into place from below. While completing this step, have an assistant lower the center drive shaft assembly from above (through the opening you cut in the tunnel). Fit the nose into the aft end of your transmission, and the tail into the nose of our Crawl Box. Also while completing this step, insert your transmission isolator between the Samurais' mounting bracket and our Front Mount. Loosely attach our Front Mount to your transmission using 4 each 8mm-1.25x25 hex head bolts and 8mm lock washers. Loosely attach our Front Mount to your transmission isolator using 1 each 8mm-1.25x30 hex head bolt, 8mm washer, 8mm lock washer, and 8mm-1.25 nylon locking nut. Loosely attach your existing transfer case support brackets (shift your transfer case as far to the driver side as you can) including our Fender Washers to bridge across the slots you cut in step 10. Verify that the center drive shaft assembly slides freely forward and aft. This indicates that the transmission and Crawl Box are in line, which is important to maintain the life of the U-joint and the Crawl Box Front Seal and Front Bearing. If it does not slide freely, first try sliding our Front Mount sideways relative to the tail of your transmission. Only if that fails, try loosening the nuts holding the Front Mount to the Crawl Box and move the two sideways and/or vertically relative to each other. (We install our Front Mount at the optimal location before shipment. Move it relative to the Crawl Box only as a last option) Also, verify that the center drive shaft is spring- loaded towards the rear of your vehicle, and that its flange (the part bolted to our Input Slip Flange) clears the bottom of your transmission tail shaft housing. Please see photos 16 and 17 below. Photo 16 Photo 17 Tighten all the bolts installed above while verifying that the center drive shaft still slides freely. This requires one person inside the vehicle to slide the drive shaft while another person underneath tightens fasteners. Re-attach the wiring to your transfer case. Re-secure the wire harness inside the tunnel. Re-attach your speedometer cable. Reinstall your existing front and rear drive shafts. Reinstall your exhaust system. Fill transfer case with gear oil. Lower your Samurai. Fill Crawl Box halfway with gear oil. Reinstall your transfer case shift lever. Reinstall the Crawl Box Shift Box and related parts removed in steps 22-29. Install the Vent Tube Hose onto the Vent Tube Barb Fitting using a Hose Clamp. Route the Vent Tube Hose into the engine bay, keeping the open end above the engine intake level, and secure. Time out - have a beer or something …     I. Cover Panel Installation   Position the Drivers Side Cover Panel. Verify full driver seat forward/aft travel without hitting our Drivers Side Cover Panel. Drill 1/16" diameter holes through the Drivers Side Cover Panel and your original sheet metal 1/2" in from the edges of our Drivers Side Cover Panel for our #6 x 1/4" sheet metal screws. (We provide screws so that these panels are easily removable for access. You may choose to use pop rivets instead if this is not a concern.) Hole spacing is up to you. Install, using RTV sealant at all seams to keep water and fumes out, using #6 x 1/4" sheet metal screws. Please see photo 18 below. Photo 18 Bend the tab aft of the transmission shift lever hole to match the angle of the Top Cover Panel. Position the Top Cover Panel. Mark on it the locations where the 2 aft transmission shift lever boot surround bolt holes are. Drill a 3/8" diameter clearance hole at each of these 2 locations. Refit our Top Cover Panel. Insure adequate clearance between all sheet metal and our Crawl Box to prevent rattles. Verify full passenger seat forward/aft travel without hitting our Top Cover Panel. Drill 1/16" diameter holes through our Top Cover Panel and our Drivers Side Cover Panel, and through your original sheet metal, for our #6 x 3/8" sheet metal screws. Install, using RTV sealant at all seams to keep water and fumes out, using #6 x 3/8" sheet metal screws. Verify fit. Please see photo 19 below. Photo 19     J. Final Details Install our Shift Boot Kits around the Crawl Box and transfer case shift levers using 4 #12 x 1/2" sheet metal screws for each. Please see photos 20, 21, and 22 below. Photo 20 Photo 21 Photo 22 Reinstall your carpets. Reinstall your transmission and transfer case shift knobs and transmission boot surround. Reinstall your seats. Test drive. Verify proper engagement of all gears. Check for leaks. Check bolt tightness. Enjoy !!! Please let us know how you like our Crawl Box.