I need to remove the gauge cluster from my 1980 450SL to lube the speedometer cable. I would also like to clean the back side of the clear gauge lenses as the previous owner was a heavy smoker and you can see it when the lights are on at night. The problem is I can't get the 10mm hex nut off to remove the steering wheel! I have tried a torque wrench, a hand impact wrench and even an air operated impact wrench on low power all to no avail. I am petrified that I will round out the hex bolt and never get it off. I have applied some liquid wrench but wonder if there is a trick of the trade that one can use to remove this bolt.
Any assistance would be most appreciated!