Photo: View (looking
forward) of front drifeshaft on 2002 build date Mk III Range Rover.
Note new flexible coupling at forward end of drive shaft where it
enters the differential. Photo courtesy of Rangerovers.net forum member
Fisha from Scotland.
Introduction
Finally in 2008, a permanent official solution to the notorious front diff failure problem was implemented
by Land Rover in a worldwide recall campaign. After many customer
complaint incidents, service bulletins and investigations by the
vehicle safety agencies of various governments, a redesign of the front
driveshaft was offered to solve the problem.
Recall Implementation
The program to replace the front drive shaft and drive flange with new
parts was technically called a "Service Action" rather than a recall.
This apparently means the customer must have the work done within a
definite time period for it to be covered. Beginning in May 2008 in the
UK and Europe, the
program spread to the US in July. A phased program was evidently needed
due to the wait for the necessary parts to be produced in sufficient
quantity. Letters are being sent out in a phased manner to all existing
owners of the 2003-2005 model affected. Also if you bring your car in
for service and it is in the affected model year range, the action
should pop up onthe dealer's monitor as something to be done. The
recall work requires about 4-6 hours of labor due to the extensive list
of parts needing to be
replaced. In the US, dealers are also providing $150 credit
towards any other work needed on your vehicle, to compensate for the
inconvenience of having to have the recall work done.
Summary of Problem and Solution
As reported on Rangerovers.net starting from the early days of the Mk
III model, the problem lay in the design of the front driveshaft, which
had no flexible coupling at the front end, so
that any minor misalignment put severe stress on the front diff input
splines, leading to failure and immobilization of the vehicle.
In our view, Land Rover's original design was perfectly reasonable
from an engineering point of view, since the engine and transmission
were all bolted together as one unit and theoretically would not need
provision for flexiblity in the drive shaft. But once the failures
started
to happen, it was obvious that the assembly must not be as rigid as
hoped, and what was needed was a driveshaft with flexible couplings at
both ends. Indeed, this was the design adopted in the 2006 model year
upgrade. However it took a long time for Land Rover to admit there was
a
real problem with the earlier models. During this period of
uncertainty, aftermarket driveshafts with the necessary flexible joints
at both ends
were produced by third party manufacturers. Now that Land Rover has
made an official solution available free fo charge, we applaud the
company for this
action which should close the door on the whole episode and help
enhance Land Rover's reputation for reliability.
Mechanical Details of
Drive Shaft Redesign Old Design:
The front driveshaft/diff design, derived from the BMW X5,
had a flexible coupling at the rear end only (see photos below left).
It therefore relied on very accurate alignment of the diff input shaft
with the
front prop shaft/drive shaft. When alignment drifted away from
perfection, the splines at this connection would be subject to
excessive wear and eventually disintegrate. Several service campaigns
to realign the diff did not seem to solve the problem permanently.
View looking rearwards showing
front driveshaft coming forward
from transfer case. Note flexible coupling at transfer case end of the
shaft.
Front end of original
driveshaft, where it enters the front diff, without flex coupling of
any kind.
New Design:
When the 2006 models came out, using
the Jaguar engines, the front driveshaft design was changed to
eliminate this reliance on accurate alignment, by providing a flexible
joint at the front end of the drive shaft (see photo below left). When
the newly designed front driveshaft finally came out, its new flexible
CV joint at the front end (photo below right) remarkably resembled the
2006 design. This also required a new carrier on the
front diff itself to accept the new driveshaft. The same simple flex
coupling as before is retained at the rear end of the shaft.
Flexible coupling used on front
end of redesigned drive shaft for 2006 and up models with
Jaguar-derived engine.
Flexible coupling at front end
of new driveshaft for 2003-2005 models. Note resemblance to 2006
design. Note new heat shield, also installed as part of the service
action, to the left of the drive shaft to shield it from the catalytic
converter.
The new design
eliminates the need for the front diff to be aligned so accurately.
Officially, the operation is referred to
as the "Front Differential to Propshaft Spline SVC Action". When I had
mine
done (September 2008) the complete list of parts used in the operation
was as follows:
In my case, during the reassembly operation the techs were unable to
crush the crush sleeve, so a new one had to be fitted (LR007771 SPACER,
BEARING).
Owner Experiences
A number of owners have reported experiencing a tighter feeling
driveline after the recall, with less slack in it. A few have noticed
subsequent drivetrain problems, such as a clunk and jerk at slow speed
while turning or flexing the
suspension (going over a speed bump). If you know anything about this,
please email me.
Introduction
