Gearbox Cross-member

As I am using the Tremec 5 Speed Manual gearbox, the standard cross-member that was supporting the C6 Auto is completely unsuitable.  It is way too low in the centre, I would have had to seriously pack the centre section up to meet the mounts or chop the cross-member and rework it to line up.  SO in the end I decided to make a new cross-member up from scratch.

The gearbox that I have came with the rear rubber mounts already attached to it, so I decided that I would utilise these, they are the usual V mounted rubber doughnut design.

I decided to make the Cross-member out of rectangular steel box section.  I cut and welded the box section into a U shape that I could weld small angled brackets that the gearbox mounting rubbers attach to.

Here you can see the start of the cross-member. This is the centre section that actually mounts to the gearbox.  I cant complete the job until my engine mounts turn up from the States as I will not know the final height that the mounts should be below the chassis rails until I get the engine in its correct location .


I finished making the cross-member by just hanging the engine and gearbox where they need to be and making the long arms up to meet the chassis rails.  I decided that I wanted to make the cross-member removable.  This means that if I need to, I can drop the gearbox out from under the truck without having to remove the engine.  I will be putting a couple of stiffening plates in the rails and welding on some captive nuts.  So once the rails are completely boxed in it will just be a matter of bolting up from underneath.

Here you can see the finished article. 


Clamped in place ready for the internal plates and captive nuts.