Car troubles: Replacing the main bearing of a viscous coupled fan of a Audi A6 C4 2.5Tdi with AAT or AEL engine

Half a million km on the clock. It is time to fail for some components

The cooling fan driven by the serpentine belt in Audi a6 2.5 tdi avant and other audis with later ael/aat diesel engines and a quite a lot of the gasoline counterparts is fixed to the engine block by a carrier which has a bearing and axle assembly. This assembly is called "flangeshaf". Its part number is 046115136 and it can be found at trshop.audi.de 

image courtesy of audi tradition shop Link to the product

image courtesy of audi tradition shop Link to the product

The price for this is currently at 190,9€ of course enthusiasts have found alternative routes to solve this problem. As it happens to be the viscous driven fan also eats up 1-5hp of engine power.

Thanks to audifinns forum for this images.

Thanks to audifinns forum for this image.

Thanks to mkvgti forum for this image.

Thanks to audifinns forum for this image.

Thanks to https://forums.quattroworld.com/s4s6/msgs/33332.phtml for this image.

Part catalog view for the later style "flangeshaf".

Thanks to https://forums.quattroworld.com/s4s6/msgs/33332.phtml for this image. On the same forum UrS695 posted his success purchasing and replacing this later style bearing. He said: "To remove the bearing I heated the housing with Oxy/Acetylene being very careful toheat even and not to overheat. Then with a punch I was able to drive the bearing out quite easily. Getting new bearing in is going to be a challenge as some folks talk of pressing it in but how do you hold that awkward housing while pressing. And one post mentioned that his bearing was slipping out of the housing. I measured the old and new bearing diameters - both measured right at 40mm on the nose so at least they are dimensionally the same. I then put the bearing in the freezer overnight. The next day I heated the housing, again careful not to give it too much and then with the bearing cold it dropped right down into the housing and hit bottom. A second later when every thing was at the same temperature it was "locked" in and would not budge."

Thanks to mkvgti forum for this image

Thanks to mkvgti forum for this image

Thanks to mkvgti forum for this image

Hand sketch for the adapter piece in place of the original bearing

Tensioner freewheel for mb w202 (alvadi.ee)

This is my own design and it should become the suitable bearing carrier piece to fit in the place of the "flangeshaf" 046115136 and to adapt the Mercedes-Benz freewheel to the bearing housing. I will post a non-blurred image when fitment is certain.

Sources:

Audifinns: https://www.audiclub.fi/audifinns/forum/tekniikka/moottori-ja-voimansiirto/40213-flektin-laakerointi-c4-a6-r5

Quattroworld: https://forums.quattroworld.com/s4s6/msgs/33332.phtml