Tractor Repair: david brown clutch adjustment, clutch disk, clutch adjustment

Question
I have a late 1960's 990 David brown selectamatic with a two stage clutch the second stage clutch for the pto will not disengage have adjusted linkage but it does not help any longer was told there is an adjustment inside at clutch that can be accessed though inspection plate underneath

Answer
 Hello,

 There are adjustable bolts on the ends of the release fingers on the pressure plate.  You can't see much through the inspection cover except the edge of the flywheel.  They should have put the inspection hole further to the rear of the tractor so it would be more accessible.  You might be able to see the release fingers to see if something is wrong, but I doubt that you can get your hand up in there to actually fix anything.  Usually, the top bell housing cover must be removed which means the fuel tank, control console and steering column must be removed first, and the tractor split apart at least 2 inches to get the cover off.  MAKE SURE YOU ENGAGE THE PTO SPEED SELECTOR LEVER BEFORE SPLITTING THE TRACTOR!!!!!   Otherwise, the engagement coupling can fall down inside the rear end of the tractor resulting in much unhappiness and foul language.   Sometimes the adjustable bolts come loose and fall out, or break, or the heads get ground off because the release bearing is siezed up.  The pto clutch disk is usually in like new condition, and the problem is with the pressure plate or the adjustable bolts


                      Good luck,

                             Arnie