In the case of a D1 (which is in your signature)
OK, I reviewed RAVE and see that you are actually quoting specs for the 'Drive shaft end play', which is just another way of saying how much the end of the drive shaft moves inward or outward. The shims are really thin washers that go on the...
unplug all the connections to the barrel mechanism. remove the ignition switch from the end of the barrel mechanism (two small phillips head screws hold it on). At that point you should be able to move the transmission selector to neutral when you move the ignition switch to position II...
Here is the thread.
work from latest to earliest....it is 13 pages long.
recommended OBD dongle...
Let's get this straight.
If you have a 1997 D1 as it says in your signature, you DO have AEL all four sensors are the same. I use these in my '97....
A pre-AEL truck will use...
They are designed to have the same possible movement. Could be a dead motor. Could be one of the little brass 'wings' inside the switch is too flat. Could be a bb missing or a spring gone rogue. Those switches are way too complicated for what they do.
Another shade tree mechanic here. It takes a bit of time to do it properly, but you should be done with a day's work.
Here is my parts list for both fronts.
I found Trevor at Rovahfarm to have the best pricing for the whole job. He is also super knowledgeable and able to add some expertise.