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Fitting an Elise Front Clam

Lotus specifies a new front Elise clamshell, or clam, must be "fitted" to the car. I searched everywhere, but could not find any documentation on exactly what "fitted" means. This post documents my experience in "fitting" a new clam to the Elise. I hope owners will be able use this post to see the work involved before they purchase a new clam.

Although my car is a series 3 Elise, the same basic methodology could be applied to all models of the Elise/Exige.

When installing body panels on a car you will need to measure the gaps between adjacent panels. I like to use rectangular spacers cut from fiberboard. The fiberboard I used was roughly 1/16" thick. Tape together packages of 2 and 3 spacers. Then use 1,2, or 3 spacers inserted in-between body panels to measure the gap. Not very precise, but it doesn't have to be. Adjusting the body panel gaps is all about what is pleasing to the eye. An exact measurement is not necessary.

You will also need a straight edge, to check the alignment of adjacent body panels. I use a 3" straight edge which I made of the same fiberboard used for the spacers, because I feel the fiberboard is less likely to scratch the paint than metal.

Centering the Clam

At this stage, I found it easier take the clam on/off the car with the door hinge cover panels removed. No lights or grills (except for the nose grill) will be on the clam.

Your first step is to place the new clam on the car and center the clam on the car. Center the clam about the windshield (pic 1). Make sure the tow hook is centered in the nose grill opening. Then center the clam off the wheels. The method I used is to tape a string with a weight to the fender, then measure from the string to the center of the wheel using a rule (pic 2).

The clam is composed of an outer shell with a number of fiberglass/plastic pieces glued to the underside. One fiberglass piece butts against the oil radiator housing. In order to center my clam, I had to cut this piece, shorten it by about 1/4" inch, and then bond it back together (pic 3).

As a final check, you can measure from the floor to the top of the fender to ensure the clam is level.

Align the Bolt Holes

The clam is held to the car by a number of bolts. Check to make sure the bolt holes in the clam line up with those on the car. In my case, almost none of the bolt holes lined up. An example is show in pic 4. The bolt hole shown was initially square, but had to be elongated in order for a bolt to be inserted.

Place the clam on the car and center it, then mark where you need to remove material. Then remove the clam and use a hand file to elongate the holes.

Pic 5 shows the "A" post metal bracket, which is used to bolt to the underside of the clam. These are on both sides of the car. The "A" post brackets can be shimmed outward if needed. In my case, I had to widen the bolt holes so the bolts would fit. I used a Dremil tool with a small grinding stone to do this.

A rule of thumb is never try to bend fiberglass. If there is a gap between the clam and the car and you tighten a bolt at that point, this can cause the fiberglass to crack. Use shims to fill the gap and eliminate any potential cracking. I had to make shims where the clam bolts to base of the windshield frame. Use a feeler gauge to measure the gap.

Check to make sure no interference exists between the new clam and the radiator hoses and Freon tubes. In my case, the driver's side radiator hose butted against the headlamp bucket. To correct, I shortened the radiator hose, which drew it closer to radiator, and created clearance between the hose and the clam.

Hang the Doors

With the clam centered, lay a straight edge across where the door and the clam are adjacent to each other. Measure the out-of-plane misalignment of the door and clam with a feeler gauge. Make sure the door is closed all the way when you do this. Put your straight edge across the rear of the door and the rear bodywork to verify the door is closed.

The door hinges are shimmed. Lotus sells shims of varying thickness in 0.010" increments, implying that any misalignment less than 0.010" is acceptable. In my case, the old clam was wider than the new clam by 1/8" on one side, and 1/16" on the other. To correct, new shims are needed for both doors. I decided to make my own shims, rather than buy them from Lotus.

To change shims, first remove the clam. Place some tape around the door hinge base to mark its original location so you can return it to its original position if needed. In order to try to prevent the door from moving when changing shims, open the door slightly and place a jack underneath the base of the door. Use a length of wood between the jack and the door to spread the load. Raise the jack until it is just snug under the door. Remember, the door is fiberglass, too much force from the jack will crack the door. Loosen the 4 bolts holding the hinge to the body and swap shims. Tighten the hinge bolts, remove the jack, put the clam back on the car and center it. Verify the door is now aligned with the clam with your straight edge.

More than likely, the door will no longer line up correctly with the rear bodywork and/or the body panel gaps around the door will be off once you change shims.

The hinge base is slotted, which allows for some movement of the door in the fore/aft and up/down directions. To adjust, put the jack under the door again and loosen the 4 hinge bolts. Use the jack to raise/lower the door. Get the top of the door level with the top of the rear clam, use your straight edge to verify. Adjust the body panel gap by sliding the hinge forward/backward. I use a wide block of wood against the hinge base and tap it with a hammer. If the body panel gap at the door/clam varies from top to bottom, correct by raising/lowering the hinge.

You may have to adjust the striker (pic 6). By loosening the hex fitting at the base of the striker it can be moved up/down and left/right. Mark the original position of the striker with tape before you adjust. Adjust so that the when the door closes it is flush with the rear bodywork. Use your straight edge to verify.

If the striker is slightly out of alignment, it is possible for the plastic lock mechanism in the door to flex when it engages the striker. This could cause the plastic to fail with enough use. The hinge bushings have some play in them, if the striker is out of alignment the entire door can shift up/down when the door closes from the play in the bushings. Watch the striker as it engages the plastic locking mechanism when the door closes to ensure the proper alignment of the door

The "A" post brackets, which hold the rear of the front clam, are slotted where they attach to the "A" post. Move them up/down so that the top of the clam is inline with the top of the door.

If you change the door hinge shims then you may need to check the vertical window angle. Too little angle will result in wind drafts and noise. Too much angle will make it hard to close the door, or even shatter the window. I used a strip of paper to adjust the window angle (pic 7). Close the door with the paper between the glass and the rubber seal, then pull the paper out. Adjustment is a matter of feeling the tension in the paper. There should be some tension in the paper, but not so much tension that it is difficult to pull the paper out. The window angle adjusted by 2 screws at the bottom of the door. Clockwise turns of the window angle screw press the window tighter against the seal when the door is closed.

Grills and Lights

All grills must be trial fitted prior to painting the clam. Trial fit the grills with the clam off the car. In my case, all of the 6 grills had to be trimmed or modified in some manner in order to fit correctly on the clam.

Trial fit the 2 headlight pods and the 2 side marker lights with the clam on the car. Also check the inner fender liners to ensure they will attach correctly.

Check the Lotus hood emblem to ensure it will fit correctly. The emblem is held to the clam with double-sided tape. To remove an emblem use dental floss or fishing line. Put the line under the edge of the emblem and work it back and forth until it saws through the tape.

The radio antenna and Styrofoam bumpers will need to be glued to the underside of the new clam. Best way to do this is with the clam off the car and upside down. This should be done prior to painting to avoid scratching the paint.

The aero flap mounting brackets, unique to the series 3, are a terrible design. When you try to remove the nuts holding it to the clam the studs will spin in the bracket. The only way to remove the brackets from the old clam is to cut the studs. Hammer out the studs and replace the studs with bolts.

Access Cover and Door Hinge Cover Panels

Drill out the rivets holding the front access cover alarm microswitch mounting plate to the original clam. Then rivet the alarm mounting plate to the new clam. Fit the alarm microswitch on the clam.

Check the fit of the access cover. I find it is easier to do this with the clam off the car. Install the access cover stud plate and mounting plate on the new clam. Then install the access cover on the clam. The 2 panel locating pins on the access cover are shimmed. Adjust the shims until the top of the access cover is flush with the top of the clam.

The access cover mounting block is shown in pic 8. The bracket on the underside of the clam which the access cover mounting blocks are bolted to is shown in pic 9. This bracket has 3 nuts welded to it, with the two outside nuts hold the mounting blocks screws. I guessed that the center nut on the bracket is used to line up mounting block with the access cover.

The holes in the clam which the mounting block screws go through are oversized, allowing the mounting block some movement in its location. Put the mounting block and its bracket on the clam with the 2 outside screws, but do not tighten the 2 outside screws. Put a third screw in the center nut on the bracket from the underside of the clam. Put the access cover on, line up the mounting block with the its male counterpart on the access cover. Then tighten the center screw, this will hold the mounting block in place. Remove the access cover, tighten the 2 outside screws on the mounting block, then remove the center screw from the bracket. The mounting block is now lined up correctly.

The access cover mounting blocks are shimmed (pic 8) as are its male counterparts. Adjust the shims until the top of the access cover in the area of the mounting blocks is in line with the top of the clam.

Once the mounting blocks are positioned correctly the 2 access cover rubber buffers can glued to the clam.

Now install the 2 door hinge cover panels (item 3 on pic 10), but do not tighten the door hinge cover panels bolts. Install the clam, be careful not to scratch the paint. Line up the bottom of the door hinge cover panel with the rocker panel beneath the door. Then line up the top of the door hinge cover panel with the lower edge of the clam. Use your straight edge if needed. Adjust the gap between hinge cover panel/door to be consistent with the gap between clam/door. Tighten the bolts on the door hinge cover panels.

More than likely, the bolting flanges at the top of door hinge cover panel will not be flush the clam bolting surface. Tightening the bolts at the lower edge of the clam (item 23 on pic 10) will cause the clam or door hinge cover panel to bend. Bending fiberglass is never a good thing. Shim (item 27 on pic 10) the gap between bolting flanges at the top of door hinge cover panel and the clam. Use a feeler gauge to measure this gap if needed. When shimmed correctly, the fiberglass will not move when the clam to door hinge cover panel bolts are tightened.

The clam has now been "fitted" to car.


1,784 Posts
Excellent write-up, thanks for taking the time to produce it.

1,028 Posts
Good Grief! Long post and write up, but appears to pale in comparison to the work involved!!

THANK YOU for providing a good reference for any unfortunate circumstance that causes one to need this!

Mods: Anyway to sticky this or something like that?

2005 Lotus Elise
874 Posts
Very detailed and informative. Making me second guess ever doing a clam replacement by myself if I ever needed to.

8,356 Posts
Great write up and thank you for sharing for all to refer to!
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