End result

This a DIY version of the Quaife Type 9 top cover that I first saw on Guy Lowe's gearbox.  It makes it much easier to check and top up the gearbox oil level.  It's a simple access hole through the top of the case made with plumbing fittings. The exact parts don't matter, I couldn't get the same parts Guy used so I improvised.

The olive is not used, the nut is simply to hold the coupler in place. It's a good idea to Loctite or lockwire the nut in place. 

Access is still a bit restricted on my car but a plastic knitting needle can bend enough to get into the hole and then drop under the chassis rail. We calibrated it by filling the box with 1.2L and then dipping it. 

You can do this mod without taking the box out though undoing the back bolts of the cover plate is... challenging!

Comments

Nice work.

I've also seen a proprietary version with a 90° spigot. Could you add a photo with it installed in the car to show the access to the hole.

Thanks

Jonathan

PS:
"Challenging" :-) 
I have no idea how i once took off and refitted my top plate, and I'd borrow someone with smaller hands in future.

Access when in my (Duratec) car is severely limited, realistically I need to drain some coolant and remove a couple of hoses - that's still much easier than using the plug on the side of the gearbox.  Access on Guy's Zetec is much more straightforward.
 

The yellow arrow points at the filler, the green one points at the chassis rail over the gearbox at the back of the engine.

 

  Freestyle Caterham #1