How To….. To change the F17/F18 gearbox oil on the Astra Mk4 Astra-Sport Disclaimer - Please note that this is a guide only and Astra-Sport take NO responsibility for any damaged caused to yourself or vehicle whilst using this guide. If you are unsure how to do something leave it to the professionals. Your Insurance and warranty might be invalidated if this modification is done. Tools required: • 11mm socket and ratchet, 13mm ring spanner, 19mm open ended spanner. • Torque wrench. • Loctite thread lock or similar. • Container to catch oil. • Stanley knife or similar (optional) • New sump plate gasket, No.90345227 on F17, No.90523143 on F18 • Hylomar gasket paste or similar (optional) • Gearbox oil 1.6L in F17 All photos show F17 gearbox, F18 is very similar so shouldn't cause a problem following this How-To. Step 1 To get the best results it's preferable to have the gearbox oil warm, take the car for a short run, 5-6 miles to get it nice and warm. I used ramps but axle stands can be used if preferred. Ramp up car or place on axle stands, allow at least 10mins for the exhaust to cool down as it will be red hot and could give you a very nasty burn. Step 2 This is the sump plate you need to remove to drain the gearbox oil. The F17 has 10 bolts holding it on, the F18 has 11 so it's easy to check which you have. The F17 is used on the 1.8 engines, both X18XE1 and Z18XE. The F18 was used on early 2.0 Astras. It's most important that you check the gasket you have is correct BEFORE you remove the sump plate, hold it against the plate to check it's correct. Thanks to Oddjob for the “How To” To”
Step 3 Using the 11mm socket and ratchet, undo the bolts holding the sump plate: work in a cross wise fashion to relieve the pressure evenly. Have a suitable container under the gearbox to catch the old oil. The bolts have been fitted using thread lock, they will be hard to undo initially. However, if when you are undoing them, they tighten up do not force them - you will strip the thread out of the gearbox if you aren't careful. Best method is to retighten the bolt as this tends to cut the thread lock off the threads, the bolt should then come out easier, repeat the process if need be until the bolt feels looser. Step 4 Leave at least one of the bolts in place but loose. Tap the sump plate with a rubber hammer or piece of wood, when it starts to give off a hollow sound the plate is due to come off. Allow all the oil to drain and remove the sump plate, check inside the bottom of the sump plate for any undue residue, small pieces of metal etc. There should be very little on the plate if the box is in decent nick. Anything other than this and consider having the box checked. Clean the sump plate until it looks like this Step 5 You can see in the photos (below) that small pieces of the old gasket remain, it's vital you remove them from both the plate and the box; I use a sharp Stanley knife edge on for this. Check the differential gear for any missing teeth etc if you want.
Thanks to Oddjob for the “How To� To�
Step 6 After cleaning the sump plate and box surfaces apply some non setting gasket paste like Hylomar, this is optional but I prefer this method in case any of the surfaces are not totally flat. Fit the gasket and refit the plate back onto the box, putting thread lock on the bolts. Tighten the bolts in a cross wise method and tighten up to the required torque, see below. Looks like this, nice and clean Step 7 Lower the car. Park the car on level ground. Remove the reverse light switch, shown in photo (below), and also the gearbox oil level plug, also pictured but on my spare box for clarity. Reverse light switch is 19mm and level plug is 13mm but you need a proper ring spanner due to its location. Make sure you clean the area around the reverse light switch before removing it, I used some carb cleaner which did the job a treat. Reverse Light Switch
Oil Level Plug
Thanks to Oddjob for the “How To” To”
Step 8 Fill the gearbox through the reverse light switch - the F17 takes approx 1.6L. When the oil starts to drip through the level plug stop filling and wait for it to stop dripping. Refit and connect the reverse light switch and refit and tighten the level plug. Take the car for a drive and check for leaks, and then wait a couple of days and recheck the level again by removing the level plug. Torque Wrench settings Never over tighten bolts in alloy components – you may strip the thread or crack the component Lower cover bolts F18 gear box F17 (alloy plate) F17 (steel plate)
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40Nm /30lbf ft 12Nm /12lbf ft 30Nm /22lbf ft
Thanks to Oddjob for the “How To” To”