hi folks.
my front diffuser underfloor has a giant hole in it which i'm attempting to fix.
is it fairly straightforward? any tips or diagrams to show how to remove/how it's bolted on?
thanks
Yes, it is pretty straightforward but can often require drilling off the heads of the button-head cap screws that go through the bottom to the stays because they will get ground down resulting in no means to loosen the screws.
It is likely different for gen 1&2 diffusers, but for the later models (I am going by memory, so I might miss something): Remove the stays from the chassis. There are two long flat head screws in the middle near the base of the tow ring that need to come out. There are six or eight screws along the rear of the diffuser that go up to the floor of the chassis. These are a pain to remove and install because you need a wrench on the nuts on top while you unscrew on the bottom. An assistant makes it easier. Another way to save effort in the future is to install self locking nut plates (not nutserts) to replace the nuts and washers on top.
Reinstalling the diffuser, fasten the stay ends to the diffuser first, and then fasten the stays to the chassis.
To remove the stays from the chassis, there is a long socket head cap screw, I think M8, and nut and washer on the inside. Not that difficult to reach.
If the stays are bowed, they can be gently reshaped by hand. Adjusting the stays is simple. There is a clevis with jam nut on each side that adjusts the rear height of the diffuser. Remove the screw that holds it in place, and rotate the clevis to adjust, refasten, and then tighten the jam nut. The forward stay adjusts the front height of the diffuser. There is a threaded coupler, one end has right hand threads and the other is left hand threads. Inspect the threads carefully so you know which way to loosen the jam nuts, and then rotate the threaded coupler.
thanks David - i removed and refitted today.
Removal was easy....curiously on my car the removal of the 6 screws along the rear of the diffuser was pretty straightforward because....they had been welded to a metal strip. (although one of them had come loose as the weld had failed), so it was reasonably straightforward to remove/refit as i only had to turn the nuts inside the cockpit.
Refitting was super fiddly.....so i guess my tip for anyone else would be attach the rear to the cockpit first, before fitting the stays.
With the stays i had to use a bit of leverage to align the hole so i could screw the bolts back through. It helped using a trolley jack to pivot and manipulate the diffuser to make it easier to align.
Next job will be to check the heights and follow your other post to adjust if i need to.....
