|
Ron Stygar Carl Buckland Dale Beuning Forums Help
From digest.v6.n870 Thu Jul 10 17:35:57 1997 (Continued from Part 2. Part 1 gave an overview and some conclusions. Parts 2 and 3 cover installation in considerable detail. Thanks again to the several people, and especially Duane Collie, whose input enabled me to do the installation and put together these instructions.- Neil) Front - Standard Method Note that the following method does not require removing the seats - which are very heavy - from the car, or disconnecting the wiring underneath them. The details given are for the standard M3 sports seats. Electric seats may differ in detail. DANGER: These seats are equipped with a pyrotechnic (explosive!) seatbelt tensioner mechanism, which you will need to disarm. Always wear suitable eye protection while working on the seat mechanism. The approved method is to disconnect the pyrotechnic tensioner trigger cable before working on the seat. However unless you have done this before, it will be much easier to disconnect slightly later in the process. Approved method: Raise the passenger seat to its maximum height. Take a flashlight, kneel outside the car, and lean in with your head near the floor in front of the seat. On the inside of the seat, against the transmission tunnel, you will see the forward end of a black plastic part in the shape of a cylinder over a rectangle. This is the pyrotechnic tensioner housing. From the rectangular lower section a black cable sleeve emerges forward, then loops out and back up to a black plastic clip with a flat top. Using needle nose pliers, raise the rear of the flat clip (difficult) to release it from its metal bracket, and push the cable sleeve and clip rearward. ***WARNING!! Never pull the cable sleeve forward, this may trigger the pyrotechnic tensioner.*** Then wiggle the cranked end of the inner braided cable inward free from its bracket, which is a couple of inches further back under the seat. The black trigger cable sleeve and its inner cable should now be completely free, pointing forward. Try to avoid any accidental contact with them, since although you have disconnected the normal trigger, tugging on the inner cable can still cause the pyrotechnic tensioner to fire. Slide the passenger seat far enough forward to expose the seat rail rear mounting bolts. Use a 16 mm socket, extension and ratchet handle to remove both bolts. Slide the seat back to expose the seat rail front mounting bolts. With a small screwdriver pry off their black plastic caps. Remove the nuts using a 16 mm socket. (I suggest you accumulate all these removed pieces in the centre console storage tray.) Drape a double folded thickness of terry towel over the centre console in the area around the front ashtray. With the passenger side door open, sit in the driver's seat, then tilt the passenger seat outward so that its backrest (which you may need to reangle) protrudes partially outside the car. Walk the seat front inward until the front mounting pad of the seat runner rests against the towel on the console and the seat is stable. Be careful how far you move the seat in order not to strain the wiring underneath. The area on which you will work is now exposed. (If you have not already disarmed the tensioner trigger, avoid contact with its cable while moving the seat.) Alternate tensioner disarming method: if you chose not to disarm the tensioner before moving the seats, do it now. With the seat propped up you will have a very clear view of the tensioner trigger cable mechanism. Working from the side of the seat, follow the steps previously described to disarm and detach the trigger cable. Now you are ready to work on the inner lap harness mount. The pyrotechnic belt tensioner and the stock seatbelt receptacle and stalk form a single assembly. Just forward of the stalk base is a shiny metal plate with two fasteners. Use a 16 mm socket to remove the nut from the rearward fastener. This will free the entire tensioner/stalk/receptacle assembly (except for a wire). Lay the assembly down toward you on the centre console. The special bolt from which you removed the nut will later be replaced with a longer one from the E36 mounting kit. Reach in with needle nose pliers, grasp the snap-ring around the inner part of the special bolt, and pull that free. You now need to unscrew the other fastener, using a T40 Torx drive socket on the exposed head and a 13 mm box end wrench to hold the nut on the inner end. Removing this frees the seat back bracket which is secured at the inner end of this Torx bolt. Push the bracket out of the way, and you are now easily able to withdraw the special bolt inward. Substitute the longer special bolt from the E36 kit, restore the seat back bracket to its normal position, and refasten the Torx bolt and nut. Replace the snap-ring around the special bolt using needle nose pliers for position and a screwdriver blade to seat it. Position the tensioner/stalk/receptacle assembly back on the special bolt. Now you will need to bend the inner lap belt mounting bracket of the Schroth harness. (Note that there is a left and a right side harness. Use the correct one: the ASM device must be on the inner shoulder harness span.) Take your time, this is very much a measure twice and bend once operation. Because the mounting plane on the seat is recessed, you need to bend the bracket in a crank shape: up and forward from the special bolt, then outward to clear the side of the seat, and up and forward again. Because of the need to go forward, these two bends will be made diagonally across the harness bracket, not straight across. Try to visualize how the bends need to be, first out one way, then back the other. Take a Sharpie and draw lines diagonally across each end of the bracket on opposite sides, where the bends need to be. Make the marks so they will be on the inside of the bends. The bends must be made as close to the bracket holes as practical. Hold the marked bracket up against the seat; do your bend plans look right? First (the order is important!) clamp the large end of the bracket and its captive harness end into a heavy vise, with the marked diagonal bend line a little above and parallel to the vise jaws. Using your hands or Channel-Locks or Vise-Grips, bend the free small end in the proper direction (with the line on the inside of the bend). The bend will tend to happen as a large radius curve but you need it sharper, so use a hammer to form the metal into a sharper bend, but not so sharp as to overstress it. Then reverse the bracket in the vise and make the required bend on the small end, in the other direction. I found I couldn't make the outward span in the bracket quite long enough, so it didn't clear the side of the seat. Putting two 5/16 inch washers on the special bolt before the bracket provides the needed clearance. With the cranked bracket on the special bolt and pointing up and forward at a 45 degree or so angle, fasten down the nut with a 16 mm socket. Lead the inner lap harness forward and lay the free end on the set. Refasten the tensioner trigger cable, and from outside the car position the seat back down on to the seat rail forward mounting studs, then spin the mounting nuts on loosely. Slide the seat forward to expose the rear mounting holes, insert their bolts and tighten securely. Slide the seat rearward again, tighten the front mounting nuts and replace their black plastic covers. Locate the black metal rail around which the stock front shoulder belt is fastened, just behind the passenger door at floor level. Pull off the plastic cover at the forward end, exposing the mounting bolt. Use a ratchet handle and Torx T50 drive to remove this mounting bolt. Keep the metal spacer, but reserve the castellated clip and the plastic cover, they won't be used while the Schroth harnesses are in place. Make sure the harness isn't twisted, then capture the harness bracket under the Torx bolt head and reassemble with the bracket pointing diagonally forward and up, and the black spacer in place between the rail and the car. Raise the seat headrest and feed the shoulder harness back between the chrome uprights, push the headrest back down to capture the harness. Now you have to do the driver's side, but it should take less than half as long. Snap the tailstrap to the connector of the front shoulder harness and your ready to roll. Front - Alternate method European Autosports (800-441-9874, ask for Patsy) sells for under $25 a bar that bridges the seat rail rear mounting bolts. It can be used to mount the crotch belt of a 5/6 point harness, as well as the lap belts. This is potentially a much simpler installation, and could also be removed easily when the harnesses are not needed. I've ordered a pair of these and will report how they work out.
Neil Maller |
