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Soft top cover and Trunkhinge Torsion Rod

This component is part of Tops. This description and photographs have has been kindly provided by Tom Kizer (TOMNISTUFF). Neither he, nor the Pagoda SL Group, take responsibility for any damage done when following these instructions.

Function

The trunk and soft top cover hinge arms share the same hinge pins and the same torsion rods, which do several jobs. The left hinge assembly connects the soft top cover to the trunk lid in such a way that it is not possible for the trunk lid and soft top cover to be fully open at the same time. The “open stop” for the soft top cover is a movable part of the left trunk lid hinge arm, so that when the trunk lid is closed, the soft top cover can open fully. When the trunk lid is opened, an open soft top cover will be forced partially closed by the movable “stop” so that the trunk lid cannot contact the soft top cover.


The left hinge assembly, viewed from the center floor of the trunk looking up and to the left.



Now removed from the car so that the relationship between the trunk lid and soft top cover arms can be understood.


The hinge pins are held in place by fold-over metal tabs. The hinge pins contain two circumferential grooves each, between the pin and the head, that provide slots for the torsion rods to ride in and reaction points for the torsion rod end levers to convert torsion into linear force.

The “Left Hinge Torsion Rod” (red in the first photo) applies force to the “Trunk Lid Arm” in the upward direction, helping to open the trunk lid against its weight. The necessary opposite reaction force is against the hinge pin groove nearest the hinge pin head in the downward direction. The opening force is not adjustable. It is determined by the design of the system.

The “Soft Top Cover and Right Hinge Torsion Rod” (yellow in the photo) rides in a slot in the lower part of the “Soft Top Cover Arm” (visible in the second photo) and applies a force in the forward direction (toward the front of the car), which would tend to pivot the soft top cover into the open position. In the photo, it can be seen that the soft top cover arm is against the “Soft Top Cover Open-Stop”. Because the trunk lid is open, that “stop” is forcing the soft top cover into a nearly closed position.


The right hinge assembly, viewed from the center floor of the trunk looking up and to the right.


On the right side, the “Soft Top Cover Hinge Arm” is not connected to the “Trunk Lid Arm”, except that they share the “Hinge Pin”. Note that the “Soft Top Cover Hinge Arm” in the third photo is in the fully closed position, since the soft top cover has been removed and there is nothing to tie it to the left “Soft Top Cover Hinge Arm”.

By comparing the two photos, it can be seen that the torsion rods have crossed between the left and right sides of the car. The yellow is in front of the red on the left side, but behind the red on the right side. The “Soft Top Cover and Right Hinge Torsion Rod” (yellow in the two photos) is riding in the grooves of the two hinge pins closest to the hinges (car outboard). The yellow torsion rod, therefore, cannot be removed first, since it is trapped by the left hinge torsion rod (red in the two photos), which rides in the hinge pin grooves nearest the heads of the hinge pins (car inboard). Near the center of the bulkhead that is between the trunk and the soft top case, just below the trunk lid seal, there are two nylon blocks through which the two torsion rods pass. The nylon blocks are bolted to a horizontal panel to stabilize the rods and probably prevent rattling of the long otherwise unsupported rods. One of the blocks is shown in the next photo, loosened and slid out of its slot, visible in the background.


The nylon block.


Removal

To remove the torsion rods the following sequence is explained below in detail.

  1. Remove the soft top cover from its hinge arms.
  2. Remove the trunk lid from its hinge arms.
  3. Remove the “Nylon Stabilizer Blocks”
  4. Release the “Left Hinge Torsion Rod” from the left hinge.
  5. Remove the “Left Hinge Torsion Rod” from the car.
  6. Remove the “Soft Top Cover and Right Hinge Torsion Rod” from the right hinge.
  7. Remove the “Soft Top Cover and Right Hinge Torsion Rod” from the “Soft Top Cover Arm”.
  8. Remove the “Soft Top Cover and Right Hinge Torsion Rod” from the car.

Reassembly of the system is the exact reverse of disassembly.

Removing the soft top cover from its hinge arms:

  • Unless you are going to repaint the hinge area of the parts, mark the soft top cover and hinge arm relative locations with your favorite method, to make reassembly location easier.
  • With the trunk lid closed and the soft top cover open, stuff heavy padding in the opening between the soft top cover and the car body to avoid damaging the paint with the unbolted soft top cover.
  • Since with the trunk lid closed, the left soft top cover hinge arm is held in the open position by the “Soft Top Cover and Right Hinge Torsion Rod”, it is easier to unbolt the soft top cover from its right hinge first, so that the soft top cover will remain open by torsion rod spring force on the left hinge. Unbolt the soft top cover from its left hinge, taking care not to drop the soft top cover onto the car paint.

Removing the trunk lid from its hinge arms:

  • Ensure that the trunk light wire is disconnected so that the trunk lid can be removed from the car. It will be a really bad surprise to realize later while holding the loose trunk lid that it is still tied to the car by the trunk light wire.
  • As with the soft top cover, if desired for easier reassembly, mark the relative positions of the hinge arms and the trunk lid.
  • Use a homemade prop rod to prop the trunk lid securely in the fully open position and stuff heavy padding in the opening between the front edge of the trunk lid and the car body.
  • Break loose, but do not unscrew, the four bolts holding the trunk lid to the hinge arms.
  • Remove the two bolts on one hinge arm and allow that corner of the trunk lid to rest on the padding.
  • While stabilizing the trunk lid to keep it from moving around, remove the two bolts on the other hinge arm and carefully lift the trunk lid off the car.

Remove the “Nylon Stabilizer Blocks”

  • With a 8 mm wrench, loosen the nylon blocks and slide them along the torsion rods and out of their sheet metal slots. They will rotate a few degrees as the torsion rods take their natural position, but without any significant force.
  • Remove the nylon blocks from the torsion rods, noting the orientation of the blocks on the pair of torsion rods.

Release the “Left Hinge Torsion Rod” from the left hinge:

Here’s where things get “interesting”, as in the ancient Chinese curse, “May you live in interesting times”. The two torsion rods, in their installed positions, each have a one-half revolution pre-load twist. They are quite stiff and can be extremely dangerous and/or expensive (in paint and bodywork) if a secure tool is not used, or if the torsion rod is allowed to escape the tool.

  • The Big Blue Book is useless for this job, since its instructions are limited to removal of the trunk torsion rod for a completely different car with a different design, using a torsion rod tool designed for a hood torsion rod of a different car with a different design.
  • Referring to PHOTO 5, the objective of a torsion rod removal tool must be to grip the torsion rod, highlighted in red, in such a way as to lift the forward part of the torsion rod out of its hinge pin groove to the location shown in green (arrow 1), and then displace it inboard (arrow 2) so that the torsion rod can be safely rotated clockwise (arrow 3) around the point where it pins into the trunk lid arm.

Movement of tool.


Removal Tool

There is a Mercedes Benz tool to remove the torsion rods from the trunk hinges. I have not found a photograph or sketch of that tool, but decided that this job is sufficiently dangerous to me and to the car, that I would make my own tool, and not trust something I did not know about. PHOTO 6 and PHOTO 7 show the tool that I made and use for removal of both torsion rods. It required a piece of 1/8 inch by 3/4 inch steel strip, a drill, a hammer, a vise, a rat-tail file, and a few short bolts, washers, and nuts.


Tool view



Tool view


The tool functions as follows: The filed deep “notch” in the end of the bar engages the straight part of the rod just inboard of the hinge pin. The bar is offset to provide clearance for the head of the hinge pin.

The complex of bolts, nuts, and bent angles at the center of the large circular bend of the torsion rod was my way of “hooking” the rod so that there would be tool contact on both sides of the rod to keep it from slipping out of the tool and a secure way of exerting a downward force on that part of the rod. In my garage, I didn’t have the equipment to do a tight Z-bend in the “hook”, so I bolted two L-bends together. Finally, the small “lock tab” bolted to the bar was designed to be able to pivot up to horizontal, once the notch and the “hook” were engaged with the rod, and then tightened to grip the rod securely to preclude any tool movement relative to the torsion rod. Before actually using the tool, I used my homemade trunk lid prop to prop up the “Left Hinge Arm” in the fully open position. Otherwise, the hinge would have just rotated with the tool when using the tool to deflect the torsion rod away from the hinge pin groove.

Once the tool was engaged with the torsion rod and the “lock tab” securely tightened, the tool was used as a lever to pivot the torsion rod around the end that engages the “Trunk Lid Arm” and lift the torsion rod out of the hinge pin groove (PHOTO 5, arrow 1), then lever it horizontally over the head of the hinge pin (PHOTO 5, arrow 2), and finally to allow the torsion rod to unwind slowly as far as possible (PHOTO 5, arrow 3) before carefully pulling the torsion rod end out of the “Trunk Lid Arm”. The part of the job illustrated by PHOTO 5, arrow 2, is the most difficult part since the torsion rod is a fixed length and has to flex somewhere between the hinges in order to get the rod over the head of the “Hinge Pin”. After pulling the torsion rod end out of the “Trunk Lid Arm”, in order to completely unwind the torsion rod to its “free” position, the torsion rod must be flexed toward the rear of the car to allow the tool to clear the edge of the trunk where the seal goes.

Remove the “Left Hinge Torsion Rod” from the car:

  • Finally, with the torsion rod in its unstressed condition, the right end of the torsion rod can be disengaged from the hinge bracket and the torsion rod removed from the car. I found it easiest to remove the Left Hinge Torsion Rod from the left side.

Remove the “Soft Top Cover and Right Hinge Torsion Rod” from the right hinge:

  • Before starting, use your homemade prop to prop fully open, the right trunk lid hinge, like you did for the left hinge, to keep it from moving during torsion rod removal.
  • Since the hinge ends of the “Left Hinge Torsion Rod” and the “Soft Top Cover and Right Hinge Torsion Rod” are mirror image, I made the removal tool so that it can be disassembled and reassembled in a mirror image form as well.
  • PHOTO 8 and PHOTO 9 show the tool configured for the “Soft Top Cover and Right Hinge Torsion Rod” removal. Actually, they are PHOTOs 6 and 7 reversed. I didn’t want to spend the time changing the configuration just for the photos, since I had done it once to do the job...

Tool reversed



Tool reversed


  • As can be seen in PHOTO 3, after the “Left Hinge Torsion Rod” (red) has been removed, the “Soft Top Cover and Right Hinge Torsion Rod” must be lifted out of the groove nearest the hinge (car outboard) and deflected farther than the other torsion rod to pass over the grooves and clear the head of the “Hinge Pin”. For me the best way was to move the torsion rod from the outboard groove to the inboard groove, then partially pull the torsion rod out of the “Trunk Lid Arm” before lifting the torsion rod out of the inboard groove to clear the head of the hinge pin. It required less deflection of the torsion rod. Except for that, the procedure is the same as for the “Left Hinge Torsion Rod” removal.

Remove the “Soft Top Cover and Right Hinge Torsion Rod” from the “Soft Top Cover Arm”.

  • Once the torque of the torsion rod has been relieved, the left end can be disengaged from the notch in the “Soft Top Cover Arm”.

Remove the “Soft Top Cover and Right Hinge Torsion Rod” from the car.

  • The “Soft Top Cover and Right Hinge Torsion Rod” can be removed from the car by flexing it and removing it from the right side.
  • To remove the “Hinge Pins”, straighten the small bend tabs that retain the hinge pins and while supporting the hinge assemblies, just slide the pins out of their holes.
  • By rotating the hinge assemblies onto their sides, they can be removed from the car from the trunk side of the bulkhead, otherwise they tend to interfere with the edges of the bulkhead openings.


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