Here you may find some helpful pictures to disamble the XERION:
http://www.modelltruckforum.com/inde...threadID=24998
...and here you find a XERION with a kit fom
www.ms-rc.de ...
http://www.modelltruckforum.com/inde...23209&pageNo=1
But: It´s only 2wd...for a 4wd I would take two modified Tamiya seering axles.
http://www.der-getriebedoktor.de/
-> shop -> tamiya truck achse -> Lenkachse...
I hope I could help you with this.
best regards
Frank