Fiberglass 911 Cab Hardtop Installation
(this is a work in-progress)
Before we begin, I would like to establish some expectations. Due to the nature of
these cars, composites, and the inherent complexities of the cab top in general, it
is unrealistic to expect it to bolt right on out of the crat and away-we-go. Every
single car is slightly different straight from the factory, and certain parts are
built so the fit can be adjusted on the car. Examples are doors, hoods and engine lids.
The OEM convertible top is the same way; the original top is adjustable in several different
Each time the factory top is removed, the entire adjustment process must be repeated.
- The three mounting brackets across the back window can be adjusted for and aft by loosening
the bolts that attach the brackets to the body.
- The rear of the top can be adjusted up or down by loosening the bolts that attach the top
to the brackets
- The B-pillar hinge can move fore and aft, and side to side. In addition, the factory
supplied plastic spacers to raise the top if necessary.
- There is an adjusting rod that attaches below the B-pillar mount
- The position of the top latches can be adjusted
When installing the fiberglass hardtop, the initial adjustments are done by making small
physical alterations to the top, ie sanding or filing small amounts of material to get
the desired fit. Once the initial installation is done, you can remove and replace the
top without having to go through the entire routine again.
Installing this hardtop requires a mild level of mechanical and bodywork expertise. It
requires a skillset similar to that required to install fiberglass quarterpanels - you
will need to be able to trim material and properly guage the fit of the part.
It is strongly recommended that the installation be carried out by a shop that's
familar with working with composites.
Other parts you will need to source
There are a few things that you will need to find in order to complete your hardtop install
- Latches - targa or cabriolet latches to match your windshield header. Pre-1986 uses 'hook'
latches, post '86 uses 'roller' latches
- Windows - rear and quarter windows (and seals) from a 1995 or earlier 911 coupe
- Seals - targa or cab door window seals
- Small "L" brackets for rear of top
If you are doing the work yourself, you will need some basic automotive and bodywork tools.
- file/rasp/SureForm - for shaping fiberglass
- drill - for drilling mounting holes
- sanding block or D/A sander
- large clamps with wide, non-marring pads
- painters blue masking tape
- 3M Super Weatherstrip Adhesive
- varying grades of sandpaper from #60 to #400
Installation High-level Overview
- uncrate the top and make sure it hasnt' been damaged in shipping.
- remove existing top
- apply blue tape to windshield header and body mount area so you don't damage your paint.
- set top in position, back-end first, to guage initial fit
- work back-to-front, making any adjustments to achieve desired fit. You may have to remove small
amounts of material to get the fit even.
- once you get the rough fit, install the body seal, then re-check the fit, starting at the back and moving forward.
- use clamps to hold top tight against the body.
- when you're happy with the fit, install rear brackets (under rear window)
- drill and bolt down B-pillars
- install front latches or bolts.
- perform finish bodywork and paint
- install seals and windows
|Targa Top Side Seal, 911 (1974-89)
||911 565 259 40 (left)
911 565 260 40 (right)
|Cabriolet Vertical Door Window to Top Seal, rear, 911 (1983-85)
||911 561 221 01 (left)
911 561 222 01 (right)
|You can also use the outer sections of the Targa bar seal 911 565 091 45
|Latches and handles - up through 1985|
|Targa Top Catch (sold per each, 2 required), 911 (1974-85)
||911 565 031 41
||For pre-1986 cars
|Targa Top Handle, 'Updated Version' 911 (1967-85)
||911 565 075 41
|Latches and handles - 1986 and later|
|Targa Top Catch, 911 (1986-89)
||964 565 031 00 (left)
964 565 032 00 (right)
|For 1986 and later cars
||Targa - Cabriolet Top Handle, 911 (1986-89)
||911 565 075 62
||For 1986 and later cars, 2 required