1992-1993 Allard J2X

Image copyright and courtesy Martin Spetz
Text copyright Michael J. Fuller

Allard J2XThe packaging at the rear is extremely tight and compact.  Unfortunately this made working on the car rather difficult.
Allard J2XThe gearbox is buried within the rear carbon substructure.  Traditionally the gearbox is bolted to or cast integrally to the bellhousing with the suspension then located off of pickups on the gearbox.  But in that installation method, all the accompanying suspension loads are absorbed by the gearbox.  But the Allard design team decided to eliminate the loads inputted into the gearbox as much as possible in order to improve longevity, an important feature for an endurance prototype.  The drawback was that the gearbox was exceedingly difficult to access, even for relatively common tasks such as ratio changes.  Gordon Friend comments, "First you remove the carbon top of the gearbox monocoque.  Then you undo the input shaft and disconnect the alternator.  Then you remove the bolts from the gearbox bobbins holding the 'box in place in the monocoque.  Then you lift the gearbox out.  But you can only do this at a somewhat awkward angle and it wasn't like it was super light!  Then with the gearbox out of the car, you can change gears relatively easy, though you do need to have a mount to put the 'box in in order to untorque it etc. Turn around time for a gear change, 2 to 4 hours!"
Allard J2XThe spring dampers were located within the rear monocoque.  Gordon Friend indicates that, unlike working on the gearbox, changing springs was actually rather straight forward and could be accomplished in about 20 minutes.

ęCopyright 2008, Michael J. Fuller