How to Replace Porsche 911 Bonnet Gas Struts – DIY Fitting Guide

Difficulty: ★☆☆☆☆
Time: Approximately 20–30 minutes
Tools: Small screwdriver, pliers and a suitable bonnet support
Part number: 91151133100

Does your Porsche 911 bonnet keep trying to knock you on the head?

One of our customers recently replaced the tired bonnet gas struts on their classic Porsche 911 and discovered that it's a surprisingly straightforward DIY job.

So, with their help, we've put together this simple fitting guide.

If your bonnet no longer stays open properly, replacing the struts is one of those small jobs that can make your 911 considerably nicer to work on.

Best of all, you don't need a workshop full of specialist Porsche tools.

Before you start

The most important thing is to securely support the bonnet before removing either gas strut.

Never rely on the remaining old strut to support the bonnet while you're working.

Use a suitable support that won't damage the bonnet or surrounding paintwork. Having another person securely support the bonnet while you work can also make the job easier.

It's also worth taking a quick photograph of the existing strut and fixings before removing anything. You'll then have an easy reference when installing the replacement.

Step 1 – Support the bonnet

Open the bonnet fully and position your support so the bonnet cannot drop while you're working.

Check that everything is stable before continuing.

Step 2 – Check the existing installation

Before removing the old strut, take a photograph showing its orientation and the position of the fixings.

It's a simple precaution, but it removes any uncertainty when installing the replacement.

We recommend changing one strut at a time.

Step 3 – Remove the retaining clip

The strut is retained at its mounting point by a pin and small retaining clip.

Carefully remove the retaining clip.

Top tip: Place a cloth underneath the area you're working on. These clips are small and have an impressive ability to disappear into inaccessible areas!

With the clip removed, take a little pressure off the strut and carefully withdraw the retaining pin.

Step 4 – Remove the old gas strut

Repeat the process at the opposite end of the strut.

Once both mounting points have been released, remove the old gas strut.

While it's removed, take the opportunity to clean around the mounting points and inspect the pins and fixings.

Step 5 – Install the new strut

Position the replacement Stabilus gas strut in the same orientation as the original.

Line up the first mounting point and reinstall the pin followed by its retaining clip.

Repeat at the opposite end.

If the mounting holes don't line up immediately, don't force the strut into position. Slightly changing the bonnet position can remove tension from the mounting point and allow the pin to slide into place.

Make sure both retaining clips are correctly seated.

Step 6 – Replace the other side

With the first replacement securely fitted, repeat the procedure on the opposite side.

Before removing the bonnet support, check all four mounting points and make sure every pin and retaining clip is securely installed.

The moment of truth

Carefully remove the bonnet support.

Lower the bonnet slightly before opening it fully again.

The bonnet should now stay securely in its open position without slowly dropping back towards you.

It's a relatively small repair, but one that makes a surprisingly big difference whenever you're working under the bonnet.

Is this a DIY job?

For most owners comfortable using basic hand tools, yes.

There are no specialist Porsche tools required and you don't need to get underneath the car.

Allow yourself around half an hour, don't rush and — most importantly — make sure the bonnet is securely supported throughout the job.

Parts used

Stabilus Porsche 911 Bonnet Gas Struts

Porsche reference: 91151133100

Need new bonnet struts for your Porsche 911?

SHOP PORSCHE 911 BONNET STRUTS →

Have you repaired your Porsche yourself?

We'd love to hear about it.

If you've fitted a Stuttgart Spares part, completed an interesting repair or have a useful tip that could help another Porsche owner, send us a photograph and a few details.

Your Porsche could appear in a future Stuttgart Spares Monthly or On the Tools feature.

This guide is provided as general information for Porsche enthusiasts. Specifications and fixing arrangements can vary between models and years. Always confirm the correct part and installation method for your particular vehicle before beginning work. If you're unsure about carrying out a repair safely, consult a qualified technician.