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Side Gearbox/Engine Mount Fitting – Astra G/H and Zafira A/B

Astra G/H 2.0 Petrol Turbo, Astra H 1.9 CDTi, Zafira A/B 2.0 Petrol Turbo and Zafira B 1.9 CDTi have a gearbox side mount that is rubber and prone to failure.

Courtenay Sport approached Powerflex to devise a solution to not only improve the original factory mount, but also give it some additional support and to help reinforce it. In some cases where the original factory mount is not too badly damaged or split, the polyurethane insert can be used to ‘save’ the failing factory mount and prevent further deterioration.

Two specifications of material are available for this mount: Yellow for road use (Shore Hardness 70) and Black (Shore Hardness 95) more aimed at trackday/competition use as it is much stiffer.

451d1ae77116a773e9520fd6adadda3ca7d66fc1.jpg OE Factory Engine Mount and Yellow Poly Insert


OE Factory Engine Mount and Black Poly Insert

We recently fitted a yellow mount insert to an Astra H VXR which had covered just over 46,000 miles and the factory mount was already showing signs of weakening due to splitting which if left would ultimately deteriorate fully and fail completely.

Once fitted there was no noticeable increase in NVH (Noise, Vibration, Harshness) into the vehicle. The vehicle used also had an uprated front engine mount insert fitted. Additionally it was noted that the gearchange had improved and became smoother due to the reduction in gearbox movement at gearchange, due to the uprated gearbox mount insert.

On vehicles with a full set of uprated engine mounts, some minor change in NVH may be experienced by fitting this additional mount.

Here is a brief fitting guide:

Disconnect the battery. To ensure the alarm siren doesn’t sound, turn the ignition on with the engine off (turn off all other electrical drains, such as the radio etc). Disconnect the negative lead first (Green Arrow) then the positive lead (Red Arrow). Leave the ignition in the ‘on’ position. Use a 10mm deep socket and ratchet.


Undo the battery clamp bolt, located at the left had side of the battery, using a 13mm socket and extension with a ratchet (arrowed but hidden in the image below). You may find on Astra H CDTi models it is easier to access the battery clamp with the turbo hose, that runs to the left of the battery, removed. Astra VXR will have plenty of clearance.


Battery clamp retaining location shown with battery removed.


Remove the battery tray. Undo 3 x 13mm bolts arrowed.


Unclip the wiring harness from the battery tray – 3 points and lift the battery tray clear.


Jack up the vehicle. Ensure the handbrake is on and the rear wheels are chocked and support on axle stands (not shown). Remove the left hand front wheel. (Astra H/Zafria B Only)


Remove the trim clip (arrowed) by pressing out the centre with a suitable tool, catch the centre piece (from behind) and pull the clip out. (Astra H/Zafria B Only)


Lift the wheel arch liner out of the way and undo the retaining nut -13mm. (Astra H/Zafira B Only)


Support the engine/gearbox using a trolley jack and piece of wood on the block/gearbox.



From underneath undo the front engine mount retaining bolt (16mm nut and bolt). Withdraw the bolt from the mount. NOTE:: If you have a 3″/76mm exhaust fitted it may not be possible to easily remove this nut and bolt as the bolt may not clear the exhaust system without removing the front pipe clamp to allow the exhaust to be moved up and out of the way. If this is the case, as an option look to remove the lower gearbox bracket instead to give clearance. See Below.



Now undo the gearbox mount to gearbox retaining bolts. 3 x torx bolts E14.


Unclip the clutch retaining pipe from the 2 clips, to allow easier access to the mount to chassis leg retaining bolts.


Undo the 4 x E12 torx bolts that hold the factory mount into the chassis leg. These are quite fiddly to access. Make a note of the bolt which has the clutch pipe retaining clip on it and the correct orientation for refitting (top arrow above image).


Once everything is undone, carefully lower the trolley jack supporting the engine/gearbox assembly.

Drop the assembly down to allow the gearbox and bracket to clear the factory mount, keeping some support on it.

The mount can now be removed from the chassis leg by tipping it from the top forward and lifting it clear.

NOTE:: If you experience it catching on the gearbox you may need to either lower the gearbox further or on M32 gearbox remove the lower mounting bracket on the gearbox. Lack of clearance can occur especially where uprated right hand side and rear engine mounts are already fitted. This may in some circumstances necessitate undoing the right hand engine mount or ON M32 gearbox, remove the lower mounting bracket also to allow clearance.

If removing the lower mount on M32 gearbox, undo the 3 x E18 Torx bolts. To gain access to the one closest to the front of the gearbox you will need to manipulate the upper gearbox mount out of the way to allow access using an extension socket. The rear one is also tight to get onto but not impossible.

Remove this lower bracket to allow clearance and then continue.

If you need to remove the right hand side engine mount, you may find it easier to raise the engine/gearbox assembly back up to make it easier to undo the right hand side engine mount bolts. You’ll need to remove the airbox assembly to access the engine mount bolts below. Again support the engine whilst this is done to ensure it is lowered evenly. Take care not to damage the sump and also you may find you need a plentiful supply of trolley jacks.

Hold the bracket in a vice and undo the bolt holding the bracket to the OE mount – T55 Torx



Sleeve the poly insert into the OE mount. Use some of the supplied grease (or some silicone spray but not too much). Get the insert started into the mount, then press face of the insert down on a flat surface, pushing it fully home into the mount.




Apply a little copperslip to the mount cut out, place the metal fitting against the poly insert (above), apply a very light smear copperslip if needed and refit the bracket tightening up the T55 bolt (Suggested Torque 55Nm).

Refit the mount and bracket into the chassis leg.

NOTE:: On M32, if you removed the lower bracket, now is the time to refit it with the original bolts – E18 Torx.

Continuing with the side mount, refit the 4 torx bolts (use a small amount of threadlock on each bolt) to secure the mount back into the chassis leg (Suggested Torque 20Nm). Take note of the bolt with the clip for the clutch pipe, and enure the correct orientation of the clip. Re clip the clutch pipe back into place. fe5a28a8861e4c4d1e66c1958274b0560b4423d3.jpg

From inside the inner wing, refit the 13mm nut to the threaded bar coming from the rear of the mount (Astra H/Zafira B Only) and then refit the trim clip. (Astra H/Zafria B Only)

Raise the engine/gearbox (which should still be supported by the jack), refit the front engine mount retaining nut and bolt.

Raise the engine/gearbox a little further and line up the holes for the gearbox bracket. Check the gearbox has cleared the poly mount insert where it sticks proud. If not you may need to push the assembly across slightly to clear the box as you relocate it back into position. Refit the 3 x Torx bolts starting them by hand and then slowly tighten a few threads at a time alternating across the bolts. If necessary lift the assembly slightly higher to make it easier.


Once the bracket is level with the top of the gearbox fully tighten the 3 x Torx bolts. (Suggested Torque 35Nm)

Fully tighten the front engine mount nut/bolt (Suggested Torque 55Nm). Once satisfied everything is tight, the supporting trolley jack can be removed.

(Astra H/Zafria B Only) Refit the front wheel, support on a trolley jack, remove the axle stand and lower the car. Torque the wheel bolts correctly (110Nm)

Refit the battery tray – 3 x 13mm bolts. Reclip the wiring harness back into place. Put the battery back into the battery and retaining clamp – 13mm bolt (8Nm).

Reconnect the battery: positive terminal first, then the negative terminal. Tighten retaining bolts, then turn off the ignition.

Road test vehicle and check everything is as it should be. Re-check wheel bolt torque after 100 miles. Important Note: E&OE. This is only a guide. If you are unsure what you are doing, seek help and advice from a professional. Courtenay Sport Ltd accept no responsibility whatsoever for any work you carry out on your own vehicle(s), or damage to property or persons.

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