REMOVING THE GEARBOX

Once the car is jacked up and

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supported securely on stands, start the job by tackling the exhaust to manifold downpipe nuts. These are 15mm when new, but 20-plus years and rust can reduce them in size – a good 6-point socket is essential. Use releasing fluid and care.

Now remove the two 13mm nuts

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securing the clutch slave cylinder to the gearbox, pull the slave away and tie wrap it out of the way – to the front wishbone is a good idea. BMW clutches can be an absolute pig to bleed out so avoid disconnecting the fluid line at all costs.

This is the connector for the exhaust 3

Lambda probe and it must be disconnected now. It’s clipped to the side of the gearbox so unclip it and carefully separate the two sections. On reassembly make sure the steel cable clips are in place and if not, renew them or use cable ties.

At the front of the car there is

4 a steel cross brace with two 16mm bolts. On Convertibles and Z3’s there is a more substantial steel cross brace with an extra four 13mm bolts to remove – be careful as the captive nuts in the chassis can spin – they can be replaced though.

Finally, undo these two 13mm nuts 5 and bolts with tension springs that secure the front and rear exhaust sections together – they’re prone to snapping. Remove the front exhaust with catalyst and Lambda probe. There is no need to remove the rear exhaust section at all.

Now disconnect the reversing light 6 switch – it’s a simple push clip fit and is easy to take off. Note that on cars with the Getrag gearbox the switch is on the passenger side, and on BMWS such as the 328i etc., have the ZF gearbox with the reversing light switch on the other side.

Now that the front exhaust section has 7 been removed, we can set to and get the aluminium heat shields off. These are secured by 10mm bolts with small washers and on the majority of cars, the alloy will have corroded around them – reassemble with bigger washers.

The next job is to disconnect the 8 rubber Giubo (yes, that’s the correct spelling, pronounced ‘Joo-bo) from the prop. Use an 18mm open-end spanner and a socket on an extension. The Giubo is looking tired after 21 years and 160k, so we replaced it with a better one.

 At the back of the car, 9 remove the four 13mm bolts and remove this transmission tunnel strengthening brace. This wasn’t fitted to Z3 cars, but it’s so quick to remove that it makes no odds. It was fitted to all E36 saloons, Coupes, Estates and Compacts however.

 Now place a decent-sized 10 trolley jack under the gearbox and pump it up slightly just to take the weight of the unit. Now undo these four 13mm bolts that secure the crossmember to the floorpan, and the two 13mm rubber mounting nuts before removing the complete crossmember.

 Now scribe the exact 11 position of the steel prop centre mount to the body and then remove the two 13mm mounting nuts. Lower the gearbox slightly, drop the prop centre first, disconnect it from the gearbox and move it to one side. No need to remove the complete prop.

 With the gearbox lowered 12 down a touch more, use a screwdriver to remove this gearchange clip. Some cars have the yellow plastic washers, some don’t. The clip part number is 25117571899 – order a new one in. Now remove the upper gear change arm as seen in photo 25.

 Now remove the bellhousing 13 bolts and starter bolts. Do the two starter bolts first – later cars from around 1997 have threaded starters, older ones have 16mm nuts. Use a hammer and drift to dislodge the starter from the dowel. Then undo the various Torx bellhousing bolts.

 Remove this 10mm bolt 14 securing the dust shield to the bellhousing. Now with the ’box on a trolley jack – or with an assistant – slide the gearbox back off the input shaft splines. It’s heavy at 30 kilos. Place a piece of wood between the head and bulkhead at this point.

 Here is the flywheel and clutch 15 and despite being a very late E36 with air-conditioning, it’s not a dual mass flywheel version. It also looks very old, and despite the age and mileage a cleanup reveals a date stamp that makes it the factory-fitted original – not bad going.

 To remove the clutch, use an 16 Allen key socket on a ratchet – hammer the Allen key bit into the bolt to ensure it’s fully in. Slacken them one by one so that the clutch cover releases gradually. There are dowels on the flywheel – use a screwdriver to ease the cover off evenly.

 The flywheel on our car is still 17 good, and all it needed was five minutes with some 180-grit emery paper to give the driven plate surface a quick clean-up. Note the reverse light and Lambda probe wiring. These love to get trapped between engine and gearbox at reassembly time.

 The clutch I fitted was an ebay 18 special – bought three years ago for a fiver – a new unused Sachs kit.

The retail is only £70-80 for these from various online suppliers, so they are hardly an expensive clutch to replace. It’s worth scanning ebay or other online buying sites for bargains though.

 Despite the dusty box, the 19 clutch kit was still pretty shiny. Beware cheap clutches that are either counterfeit junk in fake Sachs or LUK boxes (not common on older lower value stuff like this), or cheap no name no blame recons in spurious boxes, with names you’ve never heard of.

 Our clutch plate wasn’t far off 20 being down to the rivets, so it had a good run. Being 1999 manufacture it was almost certainly an asbestos clutch so take great care when cleaning everything up – use a face mask and plenty of brake cleaner to wet the dust when cleaning it up.

The new clutch goes back on the same 21 way the old one came off, making sure the ‘gearbox side’ markings face away from the engine. Note the serrated clutch linings on the new plate, apparently done to make the clutch softer on take-off and less prone to juddering when hot.

I didn’t have a clutch alignment tool, 22 so I made one using a long bolt that was a close fit in the crank spigot bearing and masking tape. Use this to hold the clutch plate in place whilst you fit the cover and torque the bolts to 24Nm on 8.8-grade bolts and 34Nm on 10.9-grade bolts.

Whilst the ’box was out, I took the 23 opportunity to replace it with a better one. After this mileage it was a bit rattly at idle, no doubt due to worn layshaft bearings. The replacement came from a 90,000-mile 1998 Z3 1.9. These Getrag 250G gearboxes are, though, extremely robust units.

Before fitting, I undid the 17mm drain 24 and refill plugs, drained the old oil and refilled with new Dexron II ATF – the same red stuff that older auto gearboxes and power steering systems use. The oil in the original box was filthy. Capacity is 1 litre on Getrag, 1.2 litres on ZF.

This is the upper gearshift arm 25 retaining clip mentioned in photo 12. It’s very tricky and you need a short narrow and sharp plate blade screwdriver to unclip it, swivel it upwards as shown here and then slide it out to release the arm. Refitting is easy as you use finger pressure.

Check the condition of this plastic 26 clutch fork pivot. Ours was okay on both original and replacement boxes, but it really is worth getting a new one in just in case. The part number is 21511223328 and it’s a couple of pounds new from BMW. It is easy to drive out and replace again.

 The clutch fork clips back on

27 as before but give it a good clean with brake cleaner. Clean the release bearing metal slide tube up with fine emery cloth until perfectly smooth, smear a very light coat of grease on it and slide the bearing on, into the fork with a dab of grease as shown.

 The release fork is not handed

28 and you can refit it either way.

Oil inside the bellhousing can be the gearbox oil seal leaking, yet it can just need the steel release bearing sleeve removing and the flange sealing – remove four bolts, clean-up and use silicon sealer.

 Before the new clutch release

29 bearing is fitted, this steel tube needs a good clean-up. This one is the 21-year-old original and was quite heavily ridged and if we were not fitting a lower mileage gearbox, we may well have fitted a new one. If not, we’d give it a serious clean-up.

 Here, the gearbox is ready to be

30 refitted. I use a couple of 6-inch long M12 studs with a metric thread. These screw into the block either side of the flywheel and the gearbox can be lifted onto these to hold the weight whilst you engage the input shaft into the clutch. Have the gearbox in gear.

 Once the gearbox is on, the

31 battle is won. That can take a bit of effort, jiggling it whilst turning the output flange to engage the splines. Having someone turn the crank pulley clockwise with a 22mm spanner helps. This is the original plastic coolant elbow – just about finished, so was renewed.

 The rubber gearbox

32 crossmember rubber mounts can be pretty tired at this age although ours were still in good condition. They are easy to replace and not expensive, with plenty of Oem-type replacements available from companies like Febi Bilstein and Lemförder.