Last time we did my fan clutch, even our 8mm allen was too large to fit between the radiator and the fan front... I think the final solution involved one of those "Squeeze Wrench" things we had lying around... it's a flattish wrench thing that goes about 1/8 of a turn per click of the handle. Rotary thingie turns at the bottom of it, so you don't have to move the handle. Pretty nifty, if Chinese. Anyway.. the smallest socket we had for the thing was 9mm... so we ended up first using the lathe to cut off a little piece of the 8mm... then crimped that down into a brass bullet casing of some kind (no I don't remember what caliber) and then flatting those edges down around it... wrapped the whole mess with a little electrical tape until the tape plus the brass layer helped it stay put inside a 9mm socket... finally got the thing out.
There are always solutions
