E30 318i: Replacing Clutch Slave-Cylinder - Quick + dirty guide!

Clutch reservoir suddenly low on fluid? Gearbox housing covered in it? Sounds like a popped slave-cylinder. Not to worry, this has to be one of the easiest to replace ever made!

* This guide covers the M40 engine and 5-speed gearbox, but process is the same for most models. *

1. Lift the left side of the car.

2. Remove the 13mm nut from the outer side of the slave-cylinder. This one is easy to access and can be got with a ring-spanner or socket, but the ratchet is quite snug to the gearbox.

3. Remove the 13mm nut from the inner side of the slave-cylinder. This is quite difficult to get to as it is inhibited by the clutch-hose as well as limited access in the trans.-tunnel. I managed it with a socket and a 4" extension bar to get past the hose/pipe. 

* I have seen someone getting that difficult to reach nut using a longer extension bar and the ratchet further back behind the gearbox, but this was not possible on my E30, so I'm guessing this may be for 4-speed boxes or older M10/M20 engines. If yours cannot be got with the details in step 3, then try this. *

4. Remove the slave-cylinder fr the gearbox and allow to hang down on the hose.

5. Clamp the hose (optional, but saves time when bleeding system later).

6. Remove the hose end from the slave-cylinder using an 11mm wrench so the old unit can be discarded. [It is much easier to grip the slave-cyl. by hand while it is removed from the gearbox and get a turn on the pipe-collar, as well as minimising leaks from the hose.]

7. Prime the new slave-cylinder by removing the bleed-nipple and carefully pouring DOT4 brake/clutch fluid into the hole at the top for the hose/pipe until the air is displaced and the fluid run out of the lower hole. It won't need much. Refit and tighten the bleed-nipple. 

8. Refit the hose-end to the slave-cylinder and remove the hose-clamp if you're using one.

9. Refit the slave-cylinder to the gearbox and tighten the two 13mm nuts.

10. Top up the clutch reservoir with DOT4 brake/clutch fluid and bleed the system of air. [Which bleeding technique you use is up to you, but for all BMW clutches I would recommend using a one-way valve attached to the bleed nipple as detailed in THIS POST, which saves time and headaches.]

E30 318i: Leaking clutch slave-cylinder... fluid low

Now the E30 is running well I took it out for a test run and noticed that all of a sudden the gears were grinding a little bit. Checked the fluid reservoir and the level had dropped to about 10mm, not good. Looked under the car and saw a spot of fluid on the drive right under the slave-cylinder. My guess, and no prizes for guessing right here, it was a leaking slave-cylinder and, hey presto... sure looks like one to me.

Replacement is ordered. I went for a cheap and cheerful one off eBay for just £16.50, though £25-40 seems to be the going rate. Be fitting this when I have chance. Looking forward to the bodywork, but mechanical jobs just keep popping up... that be old BMWs!

BMW UK Advertising Poster / Placard 1980 - M1, E21 320/6 + 6-cylinder engines

Nice 1980 placard from BMW UK advertising their family of 6-cylinder engines, from the later E21 320 to the M1's M88 and explaining the benefits of the. "Six cylinders where you'd expect to find four." in the compact 3-Series and "Six cylinders where you'd expect to find twelve." in the case of the supercar M1.

   BMW's dedication the six cylinder engine is not a recent phenomenon.

   It goes right back to BMW's original as a specialist engine-maker, rather than a car manufacturer.

   In fact, the first engines we ever built were six cylinder aircraft engines.

   Later, in the 1950's when conspicuous consumption was almost a status symbol, BMW preferred to stay with efficiency rather than extravagance and launched a six cylinder luxury car.

   Today, in the BMW 320, a car that's scarcely more than 14ft long, theres a sophisticated six cylinder power unit.

   And the BMW M1 on the right also needs no more than six cylinders. Even though in its most developed form, the engine can actually produce 800 bhp.

   It's not a blind dedication to six that makes us refuse the false economy of a four in the case of the 320. Or the wanton extravagence of a 12 in the case of the M1.

   Rather, we take our guidance from the laws of physics.

   According to those laws, it is not possible to build an engine that's perfectly balanced with less than six cylinders arranged in-line.

   Anything else, is a compromise that may help a car manufacturer balance its books. But won't help it balance its engines.

   Which is why every engine BMW make that's two litres or larger, is an in-line sic cylinder engine.

   Fortunately, there's no need for you to understand the laws of physics to discover the difference this makes.

   There's not a trace of roughness as you cruise. Or rawness as you accelerate.

   There's a smooth immediacy which motoring journalists normally describe as "turbine-like".

   And there's a flexibility which makes driving in traffic almost a pleasure. For with 85% of maximum torque at a mere 1900rpm you get a responsiveness in fourth gear that you might normally expect only in second gear.

   The BMW 320 costs £6,790.

   Which is scarcely more than cars whose manufacturers have chosen to compromise on their engines.

   And if they're prepared to compromise on the most important part of a car, where will those compromises stop?

BMW M54 Engine Wiring Harness Diagram Illustration

Illustrated diagram showing the engine wiring-harness configuration on BMWs with the M54 6-cylinder petrol/gasoline engine family, showing connections to the Vanos, GCV, DISA Valve, etc.

“TIP: Ensure your CCV system is properly connected to the underside of the intake-manifold (and it is not damaged) before connecting all of these harnesses. It’s a huge pain trying to reach through all the wires to adjust or properly connect it.”

A different take on a wiring-harness diagram done in a hand-drawn artwork style, but useful none-the-less, so it had to get catalogued. Originally posted by u/feedthedonkey on the r/BMW Tech subReddit, who claims credit for the artwork.

BMW E21 / E30 323i Engine Comparison [M20b23 2316cc]

Here's another quick engine comparison, this time the E21 and original E30 flagship models, the 323i. BMW introduced the E30 323i in 1983 using the same M20b23 2316cc injected 6-cylinder motor as the E21 had in its top model since 1977 and displacement was not increased until the better known 325i emerged in 1985. Even with sightly more weight, the E30 323i was still billed as a quicker car than its predecessor, but I have no idea what improvements were made to the engine, so lets see how the specs stack up:

M20 Engine	323i [E21]		323i [E30 <1987]
Bore	80.0mm (3.15")		80.0mm (3.15")
Stroke	76.8mm (3.02")		76.8mm (3.02")
Capacity	2316cc (141.3 cu in)		2316cc (141.3 cu in)
Comp. ratio	9.5 : 1		9.8 : 1
Power (BHP)	141 @ 5800rpm		148 @ 6000rpm
Power (PS)	142.8 @ 5800rpm		150.0 @ 6000rpm
Power (KW)	105 @ 5800rpm		110 @ 6000rpm
Torque (Lbs ft)	140 @ 4600rpm		151 @ 4000rpm
Torque (Nm)	190 @ 4600rpm		205 @ 4000rpm

A little more compression, along with a few extra horse power and a slightly higher redline make for a harder pulling engine in the high rev range, but the big difference seems to be in the torque figures. Not only does the E30 323i have a bit more, but peak-torque is delivered 600rpm lower down than the older engine and that is clearly what makes the E30 feel quicker.

BMW 1990cc [2L] Engines 4 and 6 Cylinder Comparison - M10b20 and M60/M20 [E21 320, 320i, E12]

Up to 1977 BMW used 4-cylinder engines for its original 320 and 520 models, evolving from the trusty M10 used in the 2002. After 1977 they began to use freer-revving 6-cylinder engines for all the 2 litre models, the M60 and after 1981 the M20, both still using the same 1990cc, the latter of which has evolved into all the modern BMW straight sixes we know today. The 2 litre four pot is still a very sought after power-plant though, with its light weight and torquey character making for a more responsive front-end, particularly in the smaller chassis models.

I have wanted to compare the specs of these two engines side by side for a while now to see how the bore/stroke and power outputs stack up, so here goes:

CARBURETTOR:

	M10 4-cyl.		M60/M20 6-cyl.
Bore	89.0mm (3.504")		80.0mm (3.15")
Stroke	80.0mm (3.15")		66.0mm (2.60")
Capacity	1990cc (121.4 cu in)		1990cc (121.4 cu in)
Comp. ratio	8.1 : 1		9.2 : 1
Power (BHP)	109 @ 5800rpm		120 @ 6000rpm
Power (PS)	110.5 @ 5800rpm		122.4 @ 6000rpm
Power (KW)	82.5 @ 5800rpm		90 @ 6000rpm
Torque (Lbs ft)	115.7 @ 3700rpm		118 @ 4000rpm
Torque (Nm)	157 @ 3700rpm		160 @ 4000rpm

The 6-cylinder looks to be the faster motor, making a good 10 bhp more, with the shorter stroke and higher compression ratio no doubt making for a peppier drive. However, with its longer stroke and bigger pistons, the 4-cylinder still makes very similar torque, so unless you are screaming it all the time, the lighter engine might still make a more balanced drive under normal use.

INJECTION:

	M10 4-cyl.		M60/M20 6-cyl.
Bore	89.0mm (3.504")		80.0mm (3.15")
Stroke	80.0mm (3.15")		66.0mm (2.60")
Capacity	1990cc (121.4 cu in)		1990cc (121.4 cu in)
Comp. ratio	9.3 : 1		9.8 : 1
Power (BHP)	125 @ 5700rpm		123 @ 5800rpm
Power (PS)	126.8 @ 5700rpm		125.1 @ 5800rpm
Power (KW)	94.6 @ 5700rpm		92 @ 5800rpm
Torque (Lbs ft)	126.6 @ 4350rpm		122 @ 4500rpm
Torque (Nm)	172 @ 4350rpm		165 @ 4500rpm

The injected engines are a different story, with the compression ratio of the M10 not too far behind the 6-cylinder and both making the same power, though I would say the M20 is going to pull harder and smoother as you get up the revs and, ultimately have a higher redline. On the other hand, the 4-cylinder actually seems to be giving a bit more torque this time, obviously the higher compression and bigger bore contribute to this and it is all produced lower down the rev range. This could be why I have heard M10 enthusiasts saying it is more torquey, but either way it stands to reason that the lighter, more responsive handling and low-end grunt makes the 4-cylinder a better choice for round-town driving or even short-track racing.

I actually owned one of the rare 1990cc 4-cylinder M10 engines in 2012, having been given it with the '83 E21 316 I bought. The previous owner had intended to build it up and drop it into the E21, but never got round to the project and I decided not to pursue it given that the M10b18 1.8 litre unit was plenty quick enough for the car fitted with a twin-choke Weber carb, so I sold the 2 litre lump in bits, missing suitable con-rods, for £350!

More 1977 engine changes included the 1.6 litre engine used in the E21 316 now badged as the 315. The 316 now received a restricted-power version of the 1.8 litre M10 engine and a new model, the 318, was given a hotter version of the same engine. The 316 dropped back to 1.6 litres for economies sake with the newer M4x series of engines in the late E30 and E36.

E46 318i - Broken Coolant Hose! [11537572158]

 After about 650 miles in the E46 Touring the radiator light came on. Just the amber warning, to let me know it was getting low, not the red warning when it is running out and I refilled about 1.25 litres of water / coolant to the engine. This seemed about right to me, as I feared it may be using a bit of water and there was plenty in when I bought the car so 1.25L in 650 miles isn't catastrophic and can be lived with.
About two weeks later the radiator light came on again and I dutifully refilled 1.25 litres, but the car had only covered 120 miles so I knew something was now amiss, only for the light to come on yet again after just five miles of my six mile round trip to work. Under the hood with the engine running I could see a huge pool of water in the under-tray and a drip, which after much tracing turned out to be coming from a slim rubber hose that connects to the left side of the cylinder-head [N42 engine]. It was a constant drip, but when I wiggled the hose-end the coolant began to spray round the engine-bay, so here was the culprit. Turns out the hose-connector into the head was completely sheared off, as you can see in the pic, and should extend about half an inch into the housing. The only thing holding any water into the upper engine at all was a single M6 thread screw.

The hose in question was BMW Part No. 11537572158, shown in the diagram connecting the thermostat to the cylinder-head. This is a common fault I am told on N42 and N43 engines, along with several other coolant hoses that have plastic end connectors, particularly in the US where kits can be purchased to convert the brittle plastic ends to aluminium ones. This seemed unnecessary for me, given the cost of a replacement part and the age of the car.

As there are so many coolant hose variants, finding the right used OEM one on eBay and the like can be difficult, but they do pop up. I was able to get a new spurious part through work for just £18, but I'm sure commercial motor factors will not be much more expensive as long as they have stock. Spurious hoses tend to come with a new rubber O-ring fitted. BMW dealerships will charge a premium, but at least fitment is guaranteed and they are revised parts, though these may not come with the rubber O-ring which will also need to be ordered.

F10: Clutch Bleeding Guide... the whole nightmare! [Manual transmission / gearbox 520d, 530d, F10, F11, G07, E90, E92 3er etc.]

You will need:

• Short / stubby ... wrench.
• One-way valve type bleeding-kit.
• DOT4 regular brake/clutch fluid.

Clutch-bleeding on the F10, F11, G07, E90, E92, G20 and a lot of other contemporary BMWs can be a right pain, but if you are replacing the master-cylinder / slave-cylinder, the pipework or removing your CDV, then it is necessary. If you clamp the clutch-hose by the slave-cylinder and don't allow a lot of air back into the system, then bleeding should be pretty straight forward, but if a fair bit of air does get back into the system or you are removing the master-cylinder then it can't be helped and a full bleed is needed. The trouble with a full bleed is that these systems are notorious for air locks, primarily in the master-cylinder, which can be tricky to dislodge and get fluid into.
The main drawback with a regular bleeding process, where the bleed-nipple is opened as the clutch is pumped, is that the bleed-screw is located half way up the transmission tunnel and very difficult to access with a wrench. This makes it difficult to quickly shut the bleed-valve, which is kind of essential for this process and air can get back in. If you are able to access the bleed-screw without difficulty or have some special tool designed for the job then regular clutch bleeding should work a charm with air locks and, though it may take a while, you will be on your way.
A pressure-bleeder may give the time needed to tighten the fiddly bleed-screw, but does not work to get rid of air locks and seems to bypass the master-cylinder completely, so I would avoid using one of these kits at all if there is a lot of air in the system. Some trapped air at the top of the system seems to want to exit through the reservoir anyway, so it's better not to cap it with a pressure-bleeder as it just does not seem to want to go with the flow. If you clamped the hose and only the slave-cylinder needs bleeding then a pressure-bleeder should do that in no time.
I found that a one-way valve bleed kit was the way forward. It prevents the return of air/fluid while the bleed-screw is left open and gives time to shut it when the process is complete. It leaves the reservoir open to be manually topped up, which shows precisely how much fluid is entering the system. This was the key, for me, to finally shifting the stuck air from the master-cylinder.

I have detailed the various techniques and problems below:

Location of Brake + Clutch Reservoir:

The brake/clutch reservoir is not very apparent in the engine-bay. It is located under the black panel in front of the windscreen on the driver's side of the car. Looking from the front, left-side for RHD cars and right-side for LHD. The opposite panel covers the climate-control entry-ducts.
The panel is held in place by 4 plastic clips, which can be removed by prising up the centre of the clip and then prising the base of the clip out with a panel-popper / trim-tool or a couple of flat-screwdrivers.
The fill-neck for the reservoir is right under the bonnet-hinge and pouring DOT4 in without spilling it can be tricky, so a funnel is a good idea when topping-up. I would recommend putting a towel around the reservoir also, as brake-fluid is not a nice thing to get everywhere and it is easy to over-fill. Special care should be taken when replacing the cap - the large plug that hangs under the cap will surely displace some fluid over the top of the reservoir as the cap is dropped in.

Bleed Nipple + Regular Bleeding:

Unlike BMWs of old, the bleed-nipple on the slave-cylinder is way up in the trans-tunnel and difficult to access with a regular spanner. Getting the spanner onto the bleed-screw is not a problem, but if the spanner has any length to it then no more than a few degrees of turning is possible and the valve cannot open enough. A short spanner, the one I used was about 4.5 inches long, has just about enough room to get the bleed-valve open a half-turn or more, but it is still a fiddly process, particularly with the car on low ramps and quickly shutting the valve can be tricky. This can allow air to get sucked back in before the valve is closed fully, as below.

Air Getting Sucked Back / One-Way Valve:

With only a few seconds to shut the bleed-nipple before air gets back in, I found the best solution to be a one-way valve bleed system. These are basic, widely available kits and just have a valve with a ball-bearing in the end, which sucks back and blocks the tube so no to air or fluid re-enters the bleed-nipple after each clutch stroke. At the least it makes the return of air and fluid very slow and that gives the vital time needed to shut the bleed-screw.
I used the Vizilbleed branded kit, left in the pic, and it worked brilliantly, with a soft rubber hose to fit over the nipple and a plastic collar that slides over it to make a tight seal. It also has a built-in bottle to catch fluid and, though the tube could do with being a bit longer, the kit is a bargain at £7 from Halfords. The kit on the right in the picture is even more basic, just a tube with a one-way valve at the end, but I am sure it works just as well. This Halfords branded kit was dearer at £10, but kits like these can be bought from eBay and Amazon for less.
The clutch takes a lot of pumping to get out air stuck in the master-cylinder next to the pedal and the fluid level in the reservoir needs topping-up constantly to ensure it properly fills. The section of reservoir dedicated to the clutch fills from quite high up in the bottle, so when topping up make sure you fill into the neck of the reservoir.
The one-way valve will prevent air getting back in, so the bleed-nipple can be left open and I found the best technique was to pump the clutch-pedal about 20 times, then top-up the reservoir. The level in the reservoir after the first 20 pumps should drop significantly and continue to draw more fluid after it is first filled, so make sure it is topped right up before pumping again. This should not take more than 2 or 3 goes and I found the amount of fluid that bled out of the slave-cylinder was less than I had poured in, meaning after a couple of failed bleed attempts I had finally got that stuck air out of the system.

Pressure Bleed Kit + Air Locks:

If you have clamped the clutch-hose and don't have a lot of air in the system or any air locks, then a pressure-bleed kit should work as normal. These kits, such as the Gunson Eezi-Bleed, work by pumping fluid in using air-pressure from one of the tyres. Problem is, if you do have air locks, particularly air in the master-cylinder by the pedal, then a pressure-bleed will not work to get rid of them. I found that the kit would just pump neat fluid directly through the system, giving the impression of an air-free system, but still leaving the master-cylinder full of air and no clutch-pedal. Even pumping the clutch while pressure-bleeding did not seem to clear the trapped air, I think because it wants to exit the system from the open reservoir and has been pushing against the incoming fluid pressure.
A 'reverse' pressure-bleed kit that builds up a vacuum and sucks the fluid through bleed-nipple as it is topped-up from the reservoir might be effective in getting rid of air locks, as the reservoir remains open and the fluid/air will be pulled down from the master-cylinder, rather than pumped straight past it, but I did not have chance to test one.

Back Filling + Clutch Delay-Valve (CDV):

I have seen many articles discussing back-filling of the BMW clutches to be the easiest way to clear all air from the system. This works by injecting/pumping fluid in through the bleed-nipple using a syringe or suitable pump and ejecting the air out the top of the reservoir. While this may work great for older models, modern BMWs have a slow-return valve fitted before the slave-cylinder [pictured]. This is known as the 'CDV' or Clutch Delay Valve and works by slowing the return of fluid to the master-cylinder when the clutch is engaged. This makes it impossible to dump the clutch too hard, as it ensures a nice soft engage every time. Flow from the master-cylinder to the slave-cylinder is unaffected, so the clutch releases as quickly as you like, it is just when fluid returns that it is slowed down. This is all wonderful technology, but throws its hand in when trying to back-fill the clutch to bleed it as you are pushing against the CDV.

F10 530d: Clutch Replacement [Manual 520d, 530d, 535d, F10, F11]

The clutch on my F10 has felt like it's on the way out for about a year now and over the last month or two I've noticed it starting to slip a few times, mainly when moving off in first gear with the car pointing uphill. Time to throw a new clutch in, one of my least favourite jobs and just as with everything on the 5 Series, way more involved a process than swapping a clutch into a Ford Focus. Even I was tempted to just leave the F10 with someone to do the clutch for me, but with quotes in the £1000 - £1500 range I figured it was better to bite the bullet and do it on the drive. Just as well too, as you can see from the pics to the right just how far gone the clutch was, with hardly any face left on the friction-plate and some lovely hot spots on the pressure-plate! Nice.

I'd love to say this job is the same as the E39/E60, which are pretty straight forward, but it is trickier due to updates in the car's design. The main difference is in the prop-shaft removal, the F10 requiring the rear gearbox-mount to be removed to access the bolts to the coupling. This makes it almost impossible to move the car to rotate the prop and access the top bolts, so a bit more ingenuity is needed. I also notice that the gearbox must be lowered in order to remove the slave-clyinder, which is wedged up in the trans-tunnel, something that was not necessary on the E39 and E60. The hose to the slave-cylinder also needs to be unplugged and fluid drained so the gearbox can be lowered. This is an added annoyance that BMW have engineered in here.

** Before you undertake this job yourself, it should be understood that 5-ers are complicated cars and a lot needs to be removed before the gearbox / clutch can be accessed. This is a short list...

• Main under-tray and both side trays.
• Exhaust.
• Two heat-shields.
• Brackets.
• Rear gearbox mount and bracket on back of gearbox.
• Propshaft coupling and centre-bearing.
• Starter-motor.
• Hose to slave-cylinder. [inc. refilling and bleeding of clutch].
• Only now can you remove the gearbox and swap the clutch...

But hey, if you have made it to this guide then chances are you aren't fazed by this kind of thing! So read on... the whole job can be done at home over a weekend by yourself, taking your time and enjoying yourself... or could be done in one day by two of you...

PROCESS:

** Disconnect the battery negative-terminal and put it safely out of the way. **

1. Remove the front belly-pan under-tray located below the engine and gearbox. It is held in place by 8mm screws all around the edges and a couple in the middle.

2. Remove the left and right middle under-trays. These are located under the sill on each side and held on by a lot of 8mm screws and some plastic clips.

3. Remove the centre cross-brace by undoing the eight 13mm bolts, four on each side. This is a steel plate that runs across from left-to-right near the back of the prop-shaft.

4. Remove the exhaust up to the down-pipe. First loosen the 16mm nut on the flange connecting it to the down-pipe at the front. There are then two rubber-hangers, one next to the rear-axle and one to the front of the back-box. A third rubber-hanger is located to the front of the exhaust, not far back from the down-pipe and this can be separated on its bracket by removing the two screws using an E10 double-hex (female-torx) socket. Finally there is a 13mm nut holding a bracket at the very back, up inside the rear-bumper. The exhaust can now be carefully lowered [watching the rubber-bush that has no purpose on the right of the back-box does not get caught in the bumper], worked free of the flange on the down-pipe and fully removed. If the car is high-up on a lift then you will likely need a second person for the last bit.

5. Remove the main heat-shield located above the exhaust. It is held on by several large, flat metal nuts that can be loosened with a 10mm wrench and then spun off by hand.

6. Remove the aluminium bracket that sits around the centre-bearing of the prop-shaft by undoing the two 8mm bolts holding it to the bearing and wiggling it free.

7a. Place a jack or suitable stand under the gearbox to support it so the rear mount can be removed. 

7b. Remove the rear gearbox mount by undoing the three 13mm bolts on each side holding it to the car and a single 13mm nut in the centre that holds it to the rubber-mount on the gearbox.

8a. Remove the braided electrical-earth strap at the back of the gearbox by undoing the 13mm nut attaching it to the body.

8b. Remove the bracket at the back of the gearbox that attaches it to the rear mount, by undoing the four bolts using a T55 Torx socket. Make sure the socket has good purchase here, as it can slip out easily and round the edges of the bolt-head.

9. Remove the 3 bolts holding the prop-shaft coupling (donut) to the back of the gearbox using an 18mm wrench on either side of the nut/bolt. The bolts on the upper side of the prop-coupling are difficult to get to up in the trans-tunnel. If the rear wheels are not lifted and the prop cannot be turned to get to the bolts, it is possible to get them with CV-joint type sockets as I did.

10. Undo the bracket holding the centre-bearing of the prop-shaft by removing the 13mm nut either side.

11. Uncouple the prop-shaft from the gearbox by pulling the centre-bearing down enough for the locating pin on the gearbox to be clear of the prop-coupling. The front of the prop can now be lowered and moved to the side. If you have the whole car raised on a lift, then you will need to support the front of the prop, or remove the rear coupling to the diff. and get someone else to help you lift it down.

12. Remove the live terminal from the starter-motor using a 13mm wrench and the earth-terminal using a 10mm wrench.

13. Remove the 3 screws holding the starter-motor to the engine using an E10 double-hex socket and work the starter-motor out from the gearbox.

14. Disconnect the reverse-light switch by depressing the metal wire-clip to remove the plug and unclip the wire along the gearbox.

15. Clamp the rubber-hose to the clutch slave-cylinder and disconnect the clutch-line where the slim metal tube enters the slave-cylinder. This is done by prising the metal-clip out of the connector with a small flat-screwdriver and pulling the rubber-seal out of the slave-cylinder. Don't worry too much if you cannot clamp the clutch-hose, but it will involve more bleeding later on, which is a nightmare.

16. Remove the four bolts from the lower half of the gearbox bell-housing attaching it to the sump using an E10 double-hex socket.

17. Remove the remaining 6 large bolts from the gearbox bell-housing holding it to the engine-block using an E12 double-hex socket. [As in diagram.] The 2 down each side of the bell-housing are easy enough to access, but the 2 at the top are quite tricky. There is no easy way to get them, so it might be worth feeling around the top of the gearbox with the socket only until it is on the bolt and then get the ratchet / extension bar or CV-jointed socket to them.



** CAUTION: The gearbox will now be loose and held to the engine only with the locating-pegs, so ensure it is safely supported! **

18. Gently prise the gearbox away from the engine until it is clear of the locating-pegs and held up only by the centre-spline. Rocking it side-to-side should also help here. Draw the gearbox back slowly until the centre-spline is clear of the clutch/flywheel and the gearbox can be safely lowered partially. ONLY LOWER IT ABOUT HALF WAY!

19. Disconnect the wiring-connector from the cars neutral-sensor, located at the top of the gearbox by reaching around the top while it is partially lowered and pressing in the plastic clip on the connector. Fully lowering the gearbox before disconnecting will stretch the wire and potentially snap it!

20. Fully lower the gearbox safely onto the ground.

21. The clutch is now accessible, bolted to the back of the flywheel at the back of the engine. The clutch is removed by undoing the 6 bolts around its circumference using a 6mm allen-key socket [shown in photo]. The clutch can now be prised away from the engine! Be careful the clutch does not drop at this point, so it is best to support it with one hand while loosening the final bolt.

22. Remove the release-module / bearing from the spline inside the gearbox bell-housing. The metal lever should be held in place on the opposite side to the slave-cyinder by a piece of metal-wire and after removing that it should easily pull off. [If your clutch-kit includes a new release-module that is - if you are not replacing this then leave the old one in place.]

RELAX! You are now half way through the job!

23. Clip the new bearing into the new release-module as per the clutch-kit instructions and refit it to the spline in the gearbox bell-housing, replacing the wire-clip.

24. Fit the new clutch friction-plate into the new pressure-plate and mount it to the back of the engine leaving the 6mm allen-bolts loose by a few turns so the friction-plate can be moved around inside, but will hold in position.

25. Use the correct clutch alignment-tool to centralise the clutch, or if you do not have one look directly into the centre bore of the clutch and centralise the friction-plate by hand. It does not have to be perfectly in the centre, so you can get it accurate within about 0.5mm by eye.

26. Fully tighten the 6mm all-bolts.

27. Partially raise the gearbox to leave a few inches clearance above it and reconnect the wire to the neutral-sensor.

28. Fully raise the gearbox so it is in line with the back of the engine and move it forward, guiding the centre-spline into the clutch. Rocking the gearbox left-to-right should locate the spline into the clutch plate without too much fuss and it should then be able to rotate into position to meet the locating studs. The main problem here is the height and pitch of the gearbox on the jack / gearbox-stand, so watch out for differences in the gap at the top and bottom of the bell-housing when marrying it up.

29. Reverse steps 17 to 7. For tightening-torques refer to this post - http://www.beemerlab.org/2018/11/bmw-tightening-torques.html

30. Bleed the clutch - if you clamped the hose you shouldn't have too much trouble bleeding it, but the nipple is difficult to access and it can be easy to let air back in, so I have devoted a post to my bleeding issues here - F10: Clutch Bleeding Guide... the whole nightmare! [Manual transmission / gearbox 520d, 530d, F10, F11, G07, E90, E92 3er etc.]

31. Reverse steps 6 to 1.

BMW Tightening Torques [PDF]

Superb 136-page document from BMW showing the tightening torque for every different bolt / screw on your car. It covers generic torques for all BMWs, as well as model specific ones for petrol, diesel... even the V12.

https://drive.google.com/open?id=0B1JGYWCqjPsqSTBWRGZYdFBLS3c

CONTENTS:

• General Instructions
• Engine
• Engine Electrical
• Fuel System
• Radiator
• Exhaust
• Clutch
• Transmissions and Drivetrain
• General Electrical
• Instruments
• Equipment Accessories

GENERAL TORQUES:

M4 8.8 - 2.9 Nm M4 10.9 - 4.1 Nm M4 12.9 - 4.9 Nm	M8x1 8.8 - 26 Nm M8x1 10.9 - 36 Nm M8x1 12.9 - 44 Nm	M14 8.8 - 130 Nm M14 10.9 - 180 Nm M14 12.9 - 220 Nm
M5 8.8 - 5.9 Nm M5 10.9 - 8.3 Nm M5 12.9 - 10.0 Nm	M10 8.8 - 47 Nm M10 10.9 - 66 Nm M10 12.9 - 79 Nm	M14x1.5 8.8 - 143 Nm M14x1.5 10.9 - 200 Nm M14x1.5 12.9 - 240 Nm
M6 8.8 - 9.9 Nm M6 10.9 - 14.0 Nm M6 12.9 - 16.5 Nm	M10x1 8.8 - 54 Nm M10x1 10.9 - 75 Nm M10x1 12.9 - 91 Nm	M16 8.8 - 200 Nm M16 10.9 - 280 Nm M16 12.9 - 340 Nm
M7 8.8 - 14.8 Nm M7 10.9 - 21.3 Nm M7 12.9 - 25.5 Nm	M12 8.8 - 82 Nm M12 10.9 - 115 Nm M12 12.9 - 140 Nm	M16x1.5 8.8 - 216 Nm M16x1.5 10.9 - 303 Nm M16x1.5 12.9 - 364 Nm
M8 8.8 - 24 Nm M8 10.9 - 34 Nm M8 12.9 - 40 Nm	M12x1.5 8.8 - 87 Nm M12x1.5 10.9 - 123 Nm M12x1.5 12.9 - 147 Nm	M18 8.8 - 280 Nm M18 10.9 - 390 Nm M18 12.9 - 470 Nm
		M18x1.5 8.8 - 313 Nm M18x1.5 10.9 - 440 Nm M18x1.5 12.9 - 527 Nm

E36 316i Compact: New head-gasket.

Well, it's been a busy month again in Beemer Lab and I've just bought a new house which hasn't helped. Firstly, I finally removed the stuck head-bolts from the E60, got the head off and found where my oil leak is coming from... The lower timing case has a big crack in it! It's too big a job to replace that and do the new piston, so it looks like the 530d does need a new engine after all, what a shame after my £500+ spend.

As there is no E46 progress still, I decided a cheap runaround BMW was needed on a temporary basis so I shelled out a quick £200 on an X-reg E36 316i Compact, again in Titansilver. It has 4 months tax and 10 months MOT so seemed ideal as a stop gap. That was until I went to pick up a fridge and it majorly overheated. After I limped home I found oil in the water, water in the oil and a constant bubbling from the radiator. Blown head gasket then!

I had to use it for 2 weeks in this state, only doing the 2 mile trip to work and no further, but still it was getting to max temp as I pulled up on the drive. The gasket was only £18 off eBay and is FAI. The job only took about 4 hours (oh the joys of working with a single cam!) and it is back on the road and running quite cool so far, though I will need to put it through its paces to find out if it was just a dodgy gasket or if there is a real cooling problem that's caused it.

I will cover the poor E60 and it's future in more detail soon. Oh, and I've also bought a new secondary air-pump or the E46 so watch this space. 3 Beemers and counting...

£18 delivered. eBay FTW still.

By gosh, that looks like some hot oil.

The centre two head-bolts [1 and 2] were finger loose when removed!
This has obviously allowed oil and water to mingle. Blast marks round
the front cylinder show where combustion was stopping water entering the head.
This whole head-gasket swap took about 4 hours, so how
hastily the last one was thrown on is disturbing...

Lots of burnt oil and split gasket over the head, but it cleaned up well.

Think I will leave cleaning the cooling system for another day though. The head is caked with 'rad-weld' type stuff.

Amazingly, after all that overheating, the head is straight as anything! BMW alloy heads are forgiving to say the least.

10 minutes with a razor-blade and the block is good as new. PIston don't look half bad either.

New gasket on. The re-tightening sequence is 30nm, 90 degrees and
another 90 degrees. I wonder if the last guy to work on it only did
the 30nm and forgot about the torque angling?

E60: Snapped Head-Bolts! No progress.

Well this has been the most fruitless weekend to date. First I discover the simple sump cannot be removed without lifting the engine and lowering the subframe. I am now the owner of a Clarke engine-crane, not cheap at £179.99, but it moved the job along. Next I find that to lower the subframe, almost everything must be unbolted from it - anti-roll bar, steering-rack etc. - and, once the mounts are unbolted, there is nothing stopping the engine from dropping straight onto you if something fails. I figured if I'm having the engine suspended freely above me while I work then it's best to get as much weight off it as possible, so began removing the head. The camshafts etc. came out in record time, but when I got to the head-bolts at about 12.30pm, the whole weekend's work ground to a halt.

Magnet to catch metal swarf from the drill.

Ok, it happens to us all from time to time, but I didn't expect snapped head-bolts as an added problem with the 530d rebuild. First my E14 torx-socket burst open, causing a trip to Halfords for two new ones, then 4 of the bolts snapped. Four! What a pointless setback. I did the correct removal sequence, so I must have over-tightened the head or they're just not ready to come back out after only 2 weeks, but as I got down to the last two head-bolts one of them snapped in the most awkward way imaginable - just the top of the head, leaving the giant collar and washer still incredibly tight against the head. All the other bolts did crack off slightly, the almighty creaking sound, but after that a further 3 of them stuck solid and the heads duly snapped off one by one, despite re-tightening the surrounding bolts. This hasn't half messed up the un-tightening sequence and has put the rebuild completely on hold.

Determined not to be drilled off, the head was finally
cracked off with a chisel and screwed out by hand.

I battled away until 3pm with the drill-bits I had available to me, before caving in and rushing to B&Q to buy a new 8 and 10mm titanium, again not cheap at nearly £17! I placed a large block-magnet in the head next to where I was drilling and held a smaller one to the other side in order to catch as much swarf as possible, but I will still have to give the cyl.-head and rockers a good blast in the parts-cleaner at work. The plan was to drill down the centre of the bolt head, boring it out gradually wider until the head broke away from the washer. Life is never so simple. The hole was slightly off-centre, so part of the shank was still attached even though I'd drilled well down it, so I began reaming the hole around the bolt head as much as possible. It was still stuck solid, so as a final shot in the dark I drilled a smaller hole in the rim of the bolt head and hit it with a chisel. To my amazement it cracked off and I was able to drift it round enough to become loose. I tried repeating the chisel process off the bat with the other 3 bolts, but they're having none of it, so I will have to bear out the drilling and reaming again. This is not going to be a quick thing, let alone getting that subframe down. Ah well, another week passes.

Problems to overcome:

• Drilling out stuck head-bolts.
• Getting the subframe down.
• Identifying the correct piston type.
• Clearing the head of any drilling debris.
• Identifying main source of oil leak.

E60: Engine Rebuild 1

This was complicated, but a totally realistic DIY job if you have the time. It is a lot easier than it has to be by 3 factors:

1. No need to remove the front-bumper, radiator, aux. belt and pulleys as chain is not replaced.
2. No need to fully retime as lower tensioner keeps chain on lower cog even though upper-cog is removed, pump chain is separate.
3. Obtaining a 17mm allen-key type socket to undo a front-plug and access the chain-tensioner. This is actually the only 'special tool' you need.

Hand-ground pistons and block get a final clean before new gasket is put on.

Recon head from a twin-turbo X6 diesel mates up with new Febi head-bolts and crazy torquing sequence.

Once the front plug (where the allen-key is sticking out under the belt) is removed with a 17mm male-hex (allen-key type) socket, the tensioner can be accessed. A 10mm nut below the tensioner is released to free oil-pressure, then the plunger can be pushed all the way back and a pin inserted to hold it in place - the 3mm allen-key in the picture worked for me. The oil-pressure nut is retightened after the chain is back on and the tensioner released.

Unable to turn the engine, camshafts had to be positioned by eye based on photos of before the chain was removed.

Nice dollop of fresh oil on the rockers / guides / bearings and caps.

Rocker-cover is the most involved part of the job as all the injectors / fuel pipes plumb into it.