|Tech Article Title
Changing the TT's Haldex Fluid
I decided to change the fluid and filter on my wife's TTR this
weekend. It's an easy job, and only requires one special tool, and either
a standard caulking gun or suction gun for filling
The Quattro TT's rear drive-train consists of two
components; the Haldex Coupling, and the Rear Final Drive. The Haldex
coupling is a multi-plate, wet clutch system that engages upon slip and
transfers power to the rear final drive. The Haldex Coupling is a separate
component from the Rear Final Drive, but is directly attached to it, and
requires service every 20k miles (new fluid and
I purchased a new Haldex Filter and a fluid
cartridge for this project.
Fluid - Part# G052175A1
Filter - Part#
Wrench (#T10066) I found this at Impex for $45.
5mm hex socket - drain
Oil Drain Pan
NAPA Suction Gun or Standard Caulking Gun and a
short piece of ½" vinyl tubing
I jacked the back of the
car up, and let the rear control arms rest on the top of the jackstands.
Ramps would work for this, too, if you backed the car onto them. The
Bentley indicates that the entire contents of the Haldex fluid cartridge
are injected into the coupling, so I didn't need to make sure the car was
level, as you would with a typical transmission fluid change.
To get the
filter wrench onto the filter and be able to move the wrench enough to
loosen the filter, you need to move a plastic guard that is attached to
the bottom of the gas tank. I didn't remove this gaurd completely, I just
spun off three flat, round discs that are pressed onto the screws that
protrude through the guard - note the arrows in the pic. I was then able
to hold the guard down enough to move the wrench.
Here's a pic of
the guard moved out of the way - note the arrows in the pic - these point
to the location of the retaining rings that you need to remove:
The filter came off
easily - you have limited movement and space to work, but the wrench works
well. Some fluid spilled out of the filter after it was completely
Here's a close-up of the coupling without the filter
Note what the
old filter looks like - this is the metal cased filter that came on the
car from the factory. If you've had this service done by your dealer, you
should have a nylon filter - otherwise your dealer may have omitted the
filter change as part of the service, not uncommon.
Getting the new filter on
was easy. I made sure it was threaded correctly by hand, and then used the
wrench to tighten it (Not too much torque - it's made of nylon!).
Here's a pic of the filter wrench in place:
Drain and Refill
Once the filter was changed, I opened the drain plug using a
5mm hex socket, and let the old fluid drain out. Much less fluid came out
than what was in the replacement cartridge, so I was glad to be replacing
Note the arrow in the pic pointing to the plug:
You have a couple of
options for filling the coupling back up - I chose to use a NAPA suction
gun that I had instead of putting the cartridge into a caulking gun. This
cartridge will work just fine, by the way, with a caulking gun - you just
need to use a piece of vinyl hose at the end of the cartridge so you can
angle the cartridge's plastic injection tip into the drain hole. If you
don't do this, the gun and cartridge will probably be longer than the
space between the driveway and the bottom of the car.
Here's what I
I injected the
entire contents into the coupling, and quickly pulled the gun out and
replaced the plug - tightened to 15Nm (according to the Bentley). I lost a
very minimal amount of fluid doing this. I cleaned up the bottom of the
coupling with a rag - lowered the car, and took it for a drive.
What I would do differently in hindsight:
The Bentley says to
apply a small amount of fluid onto the new filter's rubber seal - just
like you would with an oil filter. I forgot to do this.