Hoping this helps a fellow owner of a TT or other models with a Haldex.

Despite the received wisdom that not all Haldex units have a filter that can be replaced as a serviceable item, I would urge you to check with your own eyes and be 100% sure that this is the case.

I have recently had some work done to my TTS, which has a Gen 4 / OBR Haldex Unit, to resolve a fault reported by the controller (2248). This manifested itself as a TPMS fault and all power going to the front-wheels - cue lots of wheel spin if too heavy on the throttle!

The pump was replaced along with the oil being replaced. When the fault was not cleared, the unit was drained and cleaned out and the oil replaced again to try to resolve the fault - all to no avail.

Despite asking about the filter needing to be replaced and pointing at the forum post leading to the filter replacement instructions (on the TT Forum), I was told verbally and in writing that no filter exists on this model.

I collected the car (with the fault remaining) and decided to take matters into my own hands.

Having spoken with Matt at haldexrepairs.co.uk, I removed the controller to send to him for diagnostics and repair. With the car on the ramps, I also had a hunt for the filter and despite it's existence being denied, I located it and removed it in 5 minutes.

As you can see it is pretty gunked up and should be replaced, which I am doing along with fitment of the now repaired controller.

IMG_20200812_174613.jpg

Replacing the pump but leaving the filter in this state will likely lead to premature pump failure / burned out components on the controller as the pump has to work harder to overcome the resistance in the filter.

Please question harder when you are told there is no filter, to really make sure there is no filter physically fitted, and not just that the parts catalogue does not mention one!

The filters are available and can be replaced.