For those with OD troubles, it seemed that when your AOD dropped OVERDRIVE out of the blue there was only one hope - rebuilding the tranny. I admit that I rebuilt my own tranny after losing OD...



However, I don't think an overhaul is the first solution we should explore. I lost OD, and had bad shifting problems. When overhauling my AOD I found the internal clutches were burnt - but not fried. I found that my shifting problems were related to the governor on the tail shaft mostly, and partly the VB (valve body). They both were really gummed up with crap to the point that some valves on both wouldn't move. These two HUGE malfunctions can be fixed without dropping the tranny.

As for the OD going out: I found my valve body in  bad shape with crap making all the valves sticky, which lead to shift problems. The OD band was a little burnt, but not so badly it was mandatory to replace. This led me to think the OD servo must be crapped up as well. Sure enough, the OD "B" servo was gunked up and hard to move. If I hadn't replaced the servo I would have had to DIG the shit out of the cap - it was that thick. (I assume this crap accumulates on those 3-day vacation drives in OD!)

Shifting feel: It is my observation that a good cleaning of both the VB and the OD servo would obviously help bring back overdrive. Since the VB takes care of the shifting, if it was cleaned and back in operation it would also (obviously) cure poor shifting characteristics. The VB can be scary if you disassemble it completely, and I found NO reason to dismantle it all the way, just to clean it up. Sticky valves can be fixed and the junk will dissolve with carb cleaner. This route for OD resurrection is damn near FREE when compared to an overhaul!! And it can be done in your own driveway!

Tranny doesn't know when to shift: If your AOD doesn't shift down or shifts erratically, then your governor is suspect. This is what my tranny was doing also telling me to rebuild. The governor is what tells the stock VB when to shift. I found my governor stuck - not moving at all. This would be why the tranny wanted 3rd gear for take off - it was stuck at 50mph. It also conflicted with VB pressures, making it HUNT for gears. The governor is easy to fix, but getting there is another story. It does require you to drop the driveline and exhaust from the primary collectors. Once this is done you are half way there. Six more bolts and pop goes the tail shaft where you will find only the governor and speedo gear - nothing else!!

If your tranny slips in gear (like the clutches are not grabbing or pressure is not high enough to stop the slippage) then the tranny will most likely have to be rebuilt. But if the tranny holds gears fine and seems to have smooth acceleration, I don't think a tranny overhaul needs to be in your fiscal future - not yet at least.

If you explore one or more of these routes to solve your tranny problems there are a few things I suggest -

• If you are cracking the VB out and maybe even cleaning the OD servo you might think about purchasing a new OD servo. Ford sells the best "A" servo for about $75. Or, you could just clean your "B". If you buy a new one it is just one spring-clip-away from a stronger OD so I do suggest this since it is so easy to do.
• Since you have the VB off, put in a shift kit. Baumann sells a simple shift kit that will help your tranny and make you happy with your resurrected tranny.
• Clean up the VB underside of the tranny itself. This could get messy, but the more you clean the better off you are. Trannies love CLEAN!
• Before you put the pan back on, clean it well and place a common household magnet in the bottom to collect metal in the future. Of course use a new filter and good tranny fluid when you are done.

FORD sells AOD valve bodies from $80-$100. After cleaning my old VB I accidentally messed up the 3-4 accumulator valve enough that it wouldn't even go back in the hole. I opted for a new VB - this was a good choice because they come with the BEST Ford updates already installed. The Lincoln-shift-feel requires softer or even absent springs. The new FORD VB's have all the springs and good stuff. Plus you don't have to clean it - just bolt it up!

Maybe some of you guys are tranny experts - I am not. This info is just to help any of you save some green. Like I said, it only takes time and not that much money. You might spend $200 on ALL of the stuff I mentioned before you are done - the good thing is, if it doesn't work (but I'm sure it will) you have:

• A new or at least cleaner VB that will be one less step if you overhaul
• A shift kit that will also go back into your tranny if you overhaul
• A new "A" servo that will also stay in the tranny if fixed
• The only thing you will lose is time and tranny fluid

So you see, these solutions are just steps to new a tranny and I would give it a 90% success rate (10% being if your tranny is still acting up after you do this). As for tranny life, it would be hard to guess how much longer the tranny will last. It might last forever or until you sell the car -  that would be just awesome. A shift kit will help the tranny's life also to eliminate grinding more clutches and bands. Of course, if the clutches and bands are really fried (you can't tell) then the performance options you do may (may) speed up the damage - but I doubt it. I don't recommend any of this on a tranny you have not driven - a.k.a.  a mystery tranny. If your OD just went out yesterday or last month these options are your best bet, so take advantage of them. If your OD went out last year or you have gone long enough to do an oil change or two - you might have some roosted shit in there, so be cautious.  But most of you should have no problems with the methods I have specified.

By request - Things To Watch Out For

1. Be careful with the tail housing gasket when going into the governor assembly. If you mess it up, just use silly-cone (RTV). It would make life easier without tearing it in the first place, though.
2. There are two ways to do the governor: the complete way is to take the whole governor off the tail shaft, including the counterweight. If you do this the governor is held on by a snap ring, before you pull it rotate the tranny so the governor bolts are pointed DOWN.  Unsnap, pull governor back. The governor is held in rotation by a ball bearing. This ball is OPPOSITE of the bolts, on the side with the counterweight, so it is hiding up in a little hole that is now facing up - reach up there and pop it out.  And when you reinstall the governor make sure you line up the 2 feed holes, don't get it backwards. The governor is not "tight" fitting, it has slop - don't worry. If you wish not to mess with the ball bearing and snap ring, just unbolt the governor assembly (2 10mm). If you do this - make sure you know which way it faces when you reinstall - I believe the FORD P/N# goes towards the tranny.
3. DRIVELINE - make sure you install the driveline back to the pinion exactly how you found it. I suggest using a marking TOOL or metal saw to identify how the two line up. It will drive like a marital sex device if you don't. :-)
4. Make sure you bolt up the VB with the linkage in the right place, it isn't hard, but if you get it wrong you will be missing some gears - and some more fluid/time.
5. If you take any of the VB valves out of their bores for super cleaning - DO NOT SCRATCH THEM. The VB in general is a "watch out for" item - there is a LOT of stuff in there. If you take your time and do it all in one setting it isn't tough. For sticky valves - use a plastic screwdriver handle to tap on the VB in all directions till the valve moves freely. What this does is beat the impurities into the aluminum allowing he valve to move again. Make sure to keep track of the component layout/stacking in the VB - this is a MUST!! 
6. After taking out the OD servo, the OD band will spring away from the servo pin. Don't worry - look up in the hole and find the spot the pin pushes on. You can move the band around inside the tranny through holes in the bottom with a screwdriver. Over by the gear selector is a large orifice you can use to push it back over to where you want it - install the servo/spring/cover - let go of screwdriver, if the band stays where it should - put the snap ring in. This may take 2 peoples and some time.
7. Last but not least - open sores do not like carburetor cleaner - and believe me, you will be using a lot of it and your cuts and scrapes will let you know about it.

I am not a tranny pro, nor am I even certified - but experience sometimes counts for more than book learning. Who knows, I might have just flipped the AOD community upside down. . . tranny shops will be run out of business. . . okay, I doubt it, but at least they won't be taking YOUR money so soon!