Replacing the TOP - A DIY

 

DIY Boxster Convertible Top Canvas R & R

Warning: 987 model Boxster tops are different from 986 model Boxster tops. They won't fit. Nor will the hardtop from a 986 fit on the 987 or vice versa. 

 

Chris in NH was the source for the first version of this writeup and should receive credit for supplying it. Fred Adler did the original writeup. And Maurice on Long Island provided major additional explanations and pictures.

Removal and Replacement of the Boxster convertible top

Fred begins the story:

I never started out to remove and replace the convertible top on my 1998 Boxster but I always believe in researching and understanding a repair prior to getting quotes on it. My Boxster is my seventh Porsche always buying them used and it co-resides next to my “retro” Boxster, a 1971 914. The 914 taught me that when Porsches get old they are still loved as much as those rolling out of the local dealership and that a place like Pelican Parts tech reports can offer a simple alternative to finding someone who might know about your “older car” or a dealership that might know about your car. I have used the 914 tech reports and forums to fix, replace and keep driving my “retro” Boxster.

When my Boxster back window finally gave up enough of its plasticizer to crack and split after eight years in the California sun, the first place I went for guidance was the Boxster tech section. I found that there was no help on “doing it myself”. I have replaced tops twice before on previously owned MGB’s which primitive, manual tops available from many OEM sources. Those tops, like the ones found a lot of other small roadsters, seem to cost between $200 and $400 dollars and are rather simply put on by any patient owner. I also tried repairing the back window with one of those “window replacement” deals selling you “everything you need to sew in a new window”. It did not work well and after two days with bloody fingers sewing through that incredibly tough German canvas, it leaked and looked bad………………so on to the total top replacement.

I began researching all of the Boxster websites and chat rooms and all that I could find are discussions of where to buy tops for between $500 and $900 dollars followed by $1000 to $1800 labor costs to put them on. I checked ebay for tops and found the different varieties including ones with updated glass windows ranging from $390 to $1000. When you contact those sellers they recommended a “professional” installer for installation. Most of those installation quotes including tops are $2000 and up. When I related this to Pelican Parts chat rooms, they said that perhaps I should try myself and take a lot of pictures for future Boxster owners. If Boxsters do what 914’s have, most people will be trying to replace tops themselves 10 or 30 years from now.

And so, here we go.It is not easy to do and takes as much “artistic” sense as basic “handy” skills.

Choose the Top

First, choose a top. If you search the web there will be many.I decided to replace the old top with one most like the original since the updated glass window ones are more expensive and seem to have “issues” which may compromise the expensive parts and lifting mechanism found in earlier models (up to 2004) (though those seem to be worked out by now). I decided on a top made from “German canvas” (a heavy canvas like the original with a smooth finish on the outside and a “herringbone” like pattern on the inside) with a “green tinted” back plastic window. I found one on line for about $400. I took it out of the box for inspection and “feel” to make sure it was as thick as the old one.

Then I downloaded what was available on “alldata.com” since one top shop told me that is what they do. I found that information answered some questions but for the most part the diagrams are cryptic and the instructions extremely short. The Boxster top instructions are between 20 and 30 pages but still not very clear. Once I started on the top, the instructions really did not show my situation that closely.

Armed with this and confidence earned by doing several things to my 914 (fuel lines, electronic fuel systems, starters, etc. thanks to Pelican), I dove into the task of the Boxster top. I figured, how bad could it be even if I just got the old one off.

Knowing that a Boxster has a lot more parts than a 914, I used the old ziplock bag technique to keep track of the removal so I would have the best chance of reassembly correctly with no left over parts. I parked next to a long table to lay the parts out with a box of zip lock bags and a roll of masking tape to label things as I took them off. You need to make sure it is really nice and warm in your working area so the canvas top you will be putting on and taking off will be supple and as soft and loose as possible.

Here goes the top removal and installation:

1.  Put the top in “service mode” which is opening the top from 12 to 18 inches. Take out the key so there no chance of further motion.Remove the seat wind stop and seat head rest wind stops to give you more room to work.Also if you have the console which fits behind the seats, unlock and remove that also after unclipping the rear drape over the engine.

2. Uncouple the two cables on either side from the rear. You have to do all of this if you have ever opened the rear up for SMOG inspection. No smog guy will know how to do this and you should know this routine anyway.

Now you are in “service mode” and you have removed the easy things.

With the gap in the front of the top exposed you can see the front edge retaining rail.

On my 1998, this retaining rail holds in the weather seal and it held to the top frame by six T20 star screws. Remove these six T20 screws. Remove also the two T20 star screws holding in the left and right hand corners of the front convertible top seal. Bag the screws and label where they came from. You can now remove the front retaining rail and set it aside. With the doors open, you can also carefully pull out the front convertible top seal which goes across the front of the top frame and along both right and left sides of the top at the top of the window frame area.

If you find that the corners of the front seal will not easily separate from the frame, you may have a small right angle tab embedded into each corner of the seal which is hooked into a small rectangular slot in each corner of the convertible top frame front rail.If so, pull the front seal forward (about 2 inch) at each corner to unhook the tab from the slot.The front seal will now fall away once you pull the part of the seal that is pressed into the 12-inch long U shaped bracket located along both right and left sides of the top at the top of the window frame area.

Arrow shows location of small rectangular slot in left corner.You can also see the first two of four Phillips head screws which fasten the aluminum plates from underneath.The holes to the right of the first two Phillips head screws is where you removed the first two of the four Torx head screws that fasten the "U" shaped bracket to the front side rail of the convertible top frame.

3   Next you will approach removal of the sides of the roof frame. The seal at the sides of the roof frame was held on by a lower “U” shaped bracket. This is where alldata.com was wrong for my top. They did not have the front and side seals as one part as mine was. The “U” shaped bracket around 12” in length is held on by 4 T10 star screws.

     Remove each side labeling them with the masking tape as passenger and driver side and bag the screws. Once the side weatherstrip holder is removed, you will see four Philips screws. Remove these screws on each side (passenger and driver) and bag and label them.

4   Now starts the “manual” part” of removal. You will note that the canvas is likely held on with a double sided adhesive tape. I went to my local Auto Paint shop and purchased a roll of 3M auto body tape to replace this when reinstalling a new top. You will need at this time to start “peeling back” the old top from the front edge.With everything that you have removed thus far, you can peel back the front edge and continue carefully (carefully so as not to damage the top frame, bend it in any way) along both sides. The same double edged adhesive tape that was used on the front edge was also used along both sides. Additionally, there may be some black weather strip adhesive adhering the aluminum plates to the edge of the sides of the top. This will make it stickier and offer additional resistance when trying to peel away the top from the front. Be careful only not to distort or bend the aluminum plate if you don’t have new ones handy. Slow, firm and steady pull will separate the fabric-covered aluminum plate from the frame.

This is the passenger side aluminum plate with arrows showing weatherstrip adhesive remnants.

There will also be a black foam rubber strip adhered to the top frame rails along the same edges, and this strip (one on each side), which will appear compressed and crushed must be completely removed, all residue cleaned off and new ones installed prior to installation.It is important to install these black foam rubber strips carefully, being sure to position the cutouts so as to clear the screw holes (where the Phillips screws will go back in) or you risk having the foam rubber get caught up in the threads of the screws and twist itself around the screw, thereby offering increasing resistance (and ripping the foam rubber).

This is the passenger side frame rail which has now been cleaned of the adhesive and compressed black foam rubber, with the arrow showing the new black foam rubber piece ready to be installed after the white wax paper backing is removed.

Black foam rubber installed on passenger side.

Now the top is peeled back to the center support beam of the roof frame.

5   This exposes two aluminum guide sheets on either side that fit flush on the roof and to which are attached the cables which guide the top around the window frames when raising and lowering the top.

    The cable goes from the center point underneath the aluminum plate around the back of the window frame and down to a point just below the body on the “B pillar” (the roof support pillar just behind the window areas). You do not have to worry about the cables since these are provided by the top manufactures sewed into the new top. I did not cut them but rather was careful with them since you must now bend the aluminum guides to which they are attached since they need to lay flush under the new top. The cables on mine were attached to the aluminum plates by way of a rivet. The cable was attached to a spring and the spring was riveted to the aluminum plate. This assembly (spring and cable end) were shrink wrapped in plastic. I cut the shrink wrap with a razor blade and unhooked the cable “eye”. Peel the canvas top off of the aluminum sheets careful not to bend them, label the aluminum plates passenger and driver side and set aside.

6   Now you will need to detach the other side of the cable you have just been working with. As I said earlier, this cable terminates on the other end (the end fastened to the “B pillar” (the pillar behind the windows), below the body line of the car. To get at this screw, lower the top about 75%. This screw and cable will become visible.

     This was again a T20 star screw.You will note that the screw goes through a flap on the top, the lower cable eye, a plastic part which runs up from the screw called the “clamping rail and slider” and into the B pillar. Carefully remove the screw and DON”T DROP IT” since it will be really difficult to retrieve. When removed from passenger and driver side, bag them and label them. They have a lock washer. Remember the clamping rail and slider for later.

7   Now you are back to the middle support frame. The top has a flap and piping which was slid into a plastic cover on this middle frame. Note that there is a metal clip which holds this plastic cover onto the middle frame. Pry it off, noting how it was snapped in place. Now the plastic frame will lift off and you can slide the canvas flap out of it.Set aside the plastic cover for the middle frame.

You may find that the metal clip has started to rust.To avoid the possibility of the rust worsening and eventually staining the canvas top from the underside, paint the black metal clip with some rustproof paint.A paint called POR-15 is excellent for this purpose and does not require removal of all of the rust before applying.

8   At this point, I felt like I wanted to work elsewhere so I went to rear of the top and started removing it. Put the top back up to about 12-18 inches open. First there is a push in weather strip which seals the trunk from the top.

     This "fat" weather strip is inserted into what we will refer to as slot #3, which is the rearmost slot of the three slots in the blackmetal weather strip channel.

Red arrow pointing to slot #3.(Slots #2 and #1 are covered in this photo).

     This pulls out easily. Be careful since the replacement Porsche part is no doubt expensive and this sort of weather strip like the front seal can be torn. Put is aside labeling top and bottom with masking tape. Carefully peel up the top from the weather strip channel. Yes, more of that infernal double-sided adhesive tape.

This exposes another flat weather strip to the rear of another push in piece of plastic striping.This flat weather strip has a triangular cut away view and is found inserted into the #2 slot.

Solid arrow is pointing to slot #1, dotted arrow is pointing to slot # 2.You can see the ribbed gasket that is inserted into slot #1, which has now been partially pulled out for the first five inches.Note that the black metal frame has been separated from the arm on which it pivots (two 10mm bolts underneath) for the purpose of showing the slots more clearly.

Pull out the flat push down weather strip on the rearmost part of the frame. Because you have the top in “service mode”, the rear part of the top hinges loose and these strips are easier to remove. Carefully pull out this weather strip as well, label it and put it aside. Now for the top attachment to the rearmost part of the frame. Yes the adhesive was partly responsible, but the top also has a flap which was inserted in another grove parallel to the last weather strip that you removed held in place by a long wedge shaped piece of plastic that fits into that groove after the top flap in the rear was inserted into it. Pull this out and the canvas is now loose from the rearmost frame bar.

9   Now back to those “clamping rails and sliders” that you were working on just behind the “B Pillar”.

The opposite leg of the clamping rail (opposite to the one that was unscrewed when unscrewing the back end of the top cables) is also fastened with a second screw that must be removed.To see and to access this screw, the top must be pulled up and closed or almost closed.The screw can be seen from behind the rear of the canvas bottom.

The solid arrow points to the second screw.The dotted arrow points to the hole in the clamping rail where the first screw (referred to in the second paragraph of step 6 above) goes through after the screw goes through the cable eye, the serrated lock washer and the canvas.

After you have assembled the clamping rail and slider around the canvas, when you begin to slide in the assembly into place around the side of the base of the B-Pillar, be sure that you tuck the small strip of sewn-in leather (or fiberboard) (it's at the bottom edge of that flap of canvas) up under the clamping rail so that it ends up squeezed in between the clamping rail and the B-Pillar base. This is important to avoid that part of the canvas from flailing around and causing some loose material at the very base of the canvas top where it dips down below the B-Pillar base.You may have to trim some of the length of the leather (or fiberboard) strip so that it fits up there in between the short right angle legs of the clamping rail, and then you can press it in between the clamping rail and the B-Pillar base. Now, back to those clamping rails.

     You loosened them from the car when you unscrewed the back end of the top cables.They are also held on by a couple very fragile pins. The “clamping rail and slider assembly” is a two part assembly held together and to the car by two black plastic pins. These act like “hinge” pins on the assembly with the lower one holding the two plastic parts together and the upper one acting as a guide along which the clamping rail and slider can slide back and forth a few centimeters. Pull these two pins on each side with a long nose pliers being careful not to damage the clamping rail and slider assembly or you will be going to the Porsche dealer ordering those parts. Now you will note that with these two parts disassembled on each passenger and driver side that again there are top canvas flaps tucked into each component. Slide the top flaps out of them and remove them labeling them passenger and driver and noting how they went together. I reassembled them so I could not forget how they go together although it is rather obvious.

This photo shows the clamping rail (bottom plastic part), and the slider (top plastic part with slot) after they have been pulled apart but while they are still attached to the canvas.

Note: If your new convertible top does not come with two semi-elastic strings (about 4" long) that are attached to the edge of the top on each side (left and right) about midway on the canvas along the rear edge of the driver and passenger side windows, and that have the other end of the semi-elastic strings run through by one of the plastic pins that push into the top hole of the clamping rail, you will have to install updated plastic sliders. The updated plastic sliders have an extended ear jutting out from the top of the sliders that serves in place of the semi-elastic strings to guide the cable correctly when the top is closed.This photo shows the old version of the slider, with the red arrow pointing to where the extended ear has been hand drawn in for reference.You will note that he canvas top has two fabric ribs in that area, one that slides into the bottom part of the clamping rail and the other that slides into the slots along the side of the slider.In the updated slider part, there is a fourth slot where the extended ear of the slider is located and that extended ear supports the cable attached to that fabric rib further up than the older, shorter slider did.I believe that the older, shorter sliders, in combination with the semi-elastic strings were only on the earlier Boxsters, possibly 1997 to 1999.

10 You are almost THERE!! On the top support going across from the B Pillar you will note two canvas straps screwed into the cross support by two each T20 star screws.Unfasten those and put aside.

     You will also notice two (one on each side) Velcro’ed loops holding the top on the sides of the frame (“push bars”). Open those up.

11 You will now note that it seems like there is only one thing left holding on the top. You are right.The canvas top has another flap behind the flap that was slid into the #2 bar going across by way of that plastic cover. This flap, however, on bar #3 (#1 is the front one), is slid right into the bar.When you slide it out, the top comes OFF. You will figure out that this is the very first thing you do in reverse on assembly.There is no way to get this flap in place when anything else is fastening the top to the frame.

Link to Page 2, Installing the New Top