shifting AOD

I have an AOD behind my 393 windsor with a B&M hammer shifter. I havent worked up the nerve to shift manually what happens if I shift to 2nd then pull back to hold 2nd and something happens to make me back off does the trans slam down into 1st. I would experiment but I can't find a rental car with a non electronic AOD.  

generally the OEM's design the transmissions now a days to prevent trans going into 1st gear when accidently shifting into 1st above a certain road speed.  The shift valve is prevented to downshift by governor valve pressure.  The governor pressure is set by road speed and thus won't allow trans to downshift until vehical is at slower speed; usually a low speed that won't allow engine to over rev when downshifted.  

I have an AOD in my '90 Mustang daily driver. I use a B&M Street Stick (no longer produced, and is not a ratchet style) and I can tell you that if you bring it into low (1st) and let off the gas it will not down shift unless the road speed is below about 30mph (the AOD does use a governor mounted on the tailshaft).

The one thing you really want to NOT do with a stock AOD is shift UP to second and then shift back down to first to try and hold second gear. You run the risk of the band not fully releasing and burning up parts.

There are a few AOD builders out there that convert the OD to electric and allow full gear selection shifting (1-2-3). Lentech is one of them (what I have in my '90). I can let it auto shift all the way to OD, turn the OD off and auto shift to 3rd (for the track), or manually shift 1-2-3 and hold each gear as long as I like...

They can be spendy, but the trans is bulletproof. Not sure who else does the conversion, possibly Bowler Transmissions...

HTH...
Mark  
Mark Houlahan
Editor
Modified Mustangs & Fords Magazine

1965 FFR Roadster 427W/TKO-600
1966 Mustang 289-4V/C4
1968 Mustang 4.6L Three-Valve/5R55S auto
1990 Mustang 347/AOD
1998 Escort 2.0L SOHC/F4E-111 Auto
2002 Explorer Sport Trac 4.0L V-6/5R55 Auto