Drivetrain

Vehicle Details: 2002 Land Rover Discovery II.  Approx 165,000 miles.

Technician: Tyler

Initial Condition:

• Drivetrain and vehicle vibrations – more with speed
• Loud Undercarriage Noises – increasing with speed
• Loud snapping noise and vehicle stops
• Engine runs/idles fine.  No Warning lights.
• Towed in

Diagnostic Process:

Pretty simple:  a physical look undercarriage showed a broken front driveline.  The picture below is with the transmission already out of the truck.  The U-Joint on the left side is the guilty party.  This U-Joint started to fail and, because the symptom of more drivetrain vibration and noise wasn’t addressed, the joint eventually failed.  This caused the driveline to spin out of control and smash a huge hole in the transmission case.

Land Rover Discovery broken drive shaft and transmission

Here is a view further back of the damage.

Discovery transmission case broken from bad front drive line.

Conclusion:

Land Rover Discovery transmission removal

The solution is simple / although painful:  the truck needs a new transmission and drive line.  The tragedy here is that this is completely preventable:  had this come in for service when the drive train started getting loud the repair would have only been to replace or rebuild the drive line.  Any Land Rover specialist like us would proactively inspect this drive line whenever such a vehicle was in for service.  Additionally, despite having a less-than-perfect reputation in other areas, the Discovery’s transmission has actually a good reputation for reliability and longevity.

Tyler fixed it.

Here’s a fun one:  a clutch job on an E39 BMW 540i!  These are such great cars and so much fun to drive – especially with a manual transmission.  Of course sooner or later the clutch wears out and needs replacing.  I have heard from technicians more than once that this task looks daunting.  This is simply not so.  Most BMW clutches are easy to do.  Here’s some tips from this one we just did to help you conquer your fears of this job:

– First of all / yes / you have to remove the exhaust system.  Don’t argue with me and don’t worry about it.  It comes out very easily.  Soak those exhaust bolts with a good penetrating oil!

– Next you have to uncouple the driveline (or propeller shaft as we call it in my shop)  Also easy to do.  Don’t allow the center universal joint to be damaged by hyperextension.  Some people recommend marking the position of the propeller shaft relative to the transmission output – can’t hurt…

– also that big rubber ‘puck’ between the driveline and the transmission is a common wear item – if it looks crappy replace it now.  When tallking to your friendly neighborhood BMW parts supplier call it the “Guibo”.

– The transmission is pretty easy to get out but those funky bellhousing bolts require a good set of E-Torx sockets, a universal joint or two, and some long extensions.  Lower the transmission using a good (SAFE!) jack.

HERE YOU HAVE THE TRANSMISSION OUT:

– next you remove the pressure plate from the flywheel and disguard it and the the clutch disc:

Here’s the old Pressure Plate.  See the hot-spots in the surface?  This is from the clutch slipping.

Here’s the old Clutch-Disc.  This one isn’t worn down to the rivets in the friction material yet but it is close.  Also, notice that this has a sold center to it / most clutch discs have springs in this center area to allow a certain amount of wind-up to happen as the clutch engages.

Next step is to remove the flywheel from the engine:

Here’s where things get interesting.  This flywheel is called a Dual-Mass flywheel and if you play with it you’ll notice that it has two parts to it and there is a small amount of play or slip between the two.  This dual-mass slip takes the place of the springs missing in the clutch disc.

Unfortunately resurfacing dual-mass flywheels is difficult to impossible (unlike single-mass flywheels) and thus if the flywheel has any scoring or hot-spots on its surface it will have to be replaced.

Another problem here is that the bolts that hold this flywheel to the engine are trapped in this assembly and cannot be replaced without replacing the whole flywheel.  So stripping a bolt-head is a very bad thing.

Also these bolts use a ‘RIBE’ style fastener but they often are partially in-accessible due to the dual-mass nature of the flywheel.  So to remove them safely BMW have developed a special tool:

Notice how the tool is ground-down to get the head into a narrow spot?

You **can** get away with using just a normal RIBE socket tool / I’ve seen technicians do it / but it’s dangerious and remember – stripping out a bolt-head will likely mean you’ll have to replace the flywheel.

Here’s the head of the tool:

To align your new clutch you will also need a special tool that, unlike most clutch kits sold, WON’T come with your new parts – here’s what it looks like:

(One of these will be the right size…)

It is very important to get the clutch aligned correctly the first time because the pressure plate come with a pre-loaded tensioner that can only be removed once.  (See below)

Once the clutch and pressure plate are installed this center lock gets twisted counter-clockwise and removed and thrown away.  Unless you have the special pre-load tool you cannot reverse this step so be sure your clutch is aligned correctly before committing and removing this plate.

One last twist:  on the the M62 V8 Engine from BMW there is a coolant plate on the back of the engine that is only accessible with the flywheel removed.  This plate likes to leak coolant:

Here’s a scematic of it:

Obviously now is the time to replace the gasket and make sure the system is sealed.  Even if the gasket isn’t leaking right now we advocate replacing it anyway since it’s such a common problem on this engine design.

Installation, as they say, is just the reverse of removal….

A good customer brought us their work-truck with its transmission stuck in 5th gear.

We didn’t find any dirty gear lube or metal chunks in the transmission gear lube.  So we took a chance and tore this gearbox down instead of sourcing the truck a new transmission.  We got lucky, all it needed was a new 5th gear shift fork.  Here’s some pictures:

Broken Fork:

Closer view:

Here’s the new fork installed: