Wife's newly bought Explorer '93 has no OD, no engine braking on 2nd or 1st. After changing the solenoids, cleaning the valve assy, running the fault code tests, adjusing the OD and intermediate bands etc. - nothing doing. Still no OD or engine braking. So today another day under the car - luckily I have a grease pit to work from. I decided to check the trans modulator, even though it is not listed as one of the possible causes for said maladies in the ATSG manual. To my surprise (and at the same time delight) transmission fluid dripped out of the vacuum tube - a leaking vacuum diaphragm! Finally a plausible cause for the faults! So today being Saturday with no immediate replacement part available I decided to change the diaphragm. I pried open the vacuum chamber and sure enough, the membrane had come to the end of it's useful life. I cut a membrane out of an old points-ignition vacuum adjuster, crimped the vacuum chamber back together, checked that it did not leak and proceeded to put the modulator back onto the trans. I then noticed there was no actuator rod. I'm sure I didn't drop anything taking the modulator out, so what's with the actuator rod? Where did it go? I then took some measurements and made a rod 32 mm long. This is a length I thought would be right or at least safe. I put everything back in place and took the car for a test drive. For a very brief moment I had the pleasure of enjoying 2nd gear engine braking - then I guess my make-shift membrane gave up and smoke started to come out of the exhaust. Well, at least I now know the vacuum line to the transmission is tight. I have already put an order for a adjustable modulator but here's the question, at last: how long is the modulator actuator rod in an A4LD?