The 9599 tool from Porsche seems to have the same part number stamped on each of the three tools
which raises a flag to me regarding setting proper tension on the pads during timing adjustment.
When you order part 000 721 959 90 from Porsche it says three required (1 tool per bag)
BTW - I wonder if it costs so much as its name starts with Porsche 959_
For instance we know the spring load on the standard tensioners for bank 1 and bank 2 are similar
and the IMS spring tensioner (middle one) has much less tension on the spring.... I'll try to
measure the pressure today if I get a chance. But the manual says to insert the 9599 tool into
each of the tensioner holes and then adjust the pre-tension force (there is a little stem that
appears at the end of the nut when proper tension is achieved) (see pic below)
So if each of the three pre-tensioners are the same, and each is adjusted to the same pre-load
point then the pre-load force must be the same on each; and since we know the springs aren't
the same strength on the stock 3 tensioners, I'm lead to believe that this 9599 tool does nothing
else then keep enough additional pressure on the tensioner pads to minimize slack/movement
during timing adjustment, as otherwise each of the 3 tools would be different!
I suppose I could drop a second spring inside the bigger spring already in the tensioner and use the
bolt to compress the inside spring which would add tension, instead of restricting travel.... but for the
sake of getting the timing right, I think key is to adjust based on little to no slack (which the stock
tensioner limits under pressure and oil flow)
BTW Just out of curiosity I checked the pressure on the 14yr old vs new tensioners
The preload readings I got on stock
OLD tensioners (no oil) - travel limit on each ~22mm
IMS Tensioner top 8.6 lbs to bottom 14.2 lbs
Bank 2 Tensioner top 17.4 lbs to bottom 40.9 lbs
Bank 1 Tensioner top 17.2 lbs to bottom 39.9 lbs
The preload readings I got on the
NEW tensioners (no oil) - travel limit on each ~21mm
IMS Tensioner top 11.2 lbs to bottom 17.8 lbs
Bank 2 Tensioner top 21.1 lbs to bottom 46.0 lbs
Bank 1 Tensioner top 21.0 lbs to bottom 46.0 lbs
