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66-96 Ford Broncos - Early & Full Size
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AOD Shift Shaft (Linkage) Seal Replacement

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I have found plenty of articles about a leaking shift shaft seal and found often people buying the seals but after 7 years still never fixed it cuz like myself, they were afraid of what to do since there really wasn't any useful info.

I finally did it and it was pretty easy! Below is a PDF from Lokar that explains how to replace the selector arm in great detail. There are also videos out there now as well. The AOD Linkage video from Monster Transmissions is very helpful! These videos and instructions explain everything EXCEPT the seals themselves. I explain the whole process, include the tool sizes you'll need, and then cover the seals which immediately follows the steps outlined in the PDF and video I suggest. I would have pictures, but as you know, or will find out, this job does not permit cameras. Good luck!
Ford AOD, AODE, 4R70W Transmission Linkage 
8mm socket (inside transmission)
3/8 socket (transmission pan bolts)
1/2 socket/wrench (TV linkage outside)
13/16 wrench if you have offset use it! (selector/TV nut inside tranny)
big box end wrench for holding the selector
Lots of towels and soap
-New transmission filter since you might as well. The gasket looks like you can flip it either way but that is NOT true. It goes only one way. The two points where the pan angles in, you'll see an offset of these bolt holes. Don't screw it up. The WIX filter comes with a new rubber gasket and is awesome! It also allows you to thread all bolts into the gasket prior to raising your pan and holds them nicely.
-Recommend new pan. 
---If you go with B&M 3 quart rigid case pan, be ready to drill or cut some new notches into your crossmember otherwise you will never get those rear 2 pan bolts in. I found this out post installation and was not fun but doable. If this is the route you're taking, it may not hurt to cut things now but you'll need to measure first. No measuring needed when the pan is up there since you can see where you need the holes now.
-New seals; TV and linkage seals. I had to call around and finally a couple transmission shops told me about TransStar which is the local warehouse to pick stuff up like that. Point in case, you might need to call around to get what you need.
Undo TV linkage with 1/2in socket. Here's your first seal too, though hard to see. That's the TV seal. This will be the smaller of the two seals you should have picked up. You can replace it now or later when you'll have the part in hand.
Transmission bolts are 3/8 and I found a 1/2 in there for whatever reason. It's a rebuild and the shop sucked.
The rest of the bolts are all 8 mm and if not something went wrong.
You need a 13/16 wrench for the nut that holds the shift shaft inside. I used a wrench on the outside of the tranny on the top side of the selector arm with the round end of the wrench on the shaft bolt itself to brace while I unscrewed the nut about 1/4 turn and that's as far as it wanted to go. That pipe that you're going to hit with the wrench? It's ok, it's actually a pick up tube and pushes up inside and will return automatically so you have a little more room and don't have to worry about breaking it.
I also had to use a pair of needle nosed vice grips with rubber hosing on the tips so I wouldn't scratch anything, but still get enough grip to continue to turn the nut after the wrench would go no more.
Next remove the guide pin they mention in the articles. If you didn't read it, or it's gone, it will be that tiny pin going vertically inside the case. You'll use a pair of wire cutter/dykes to remove this. Just pry gently and it will slide out. It's about 1 1/4in long, and do NOT push it in too far either. This keeps or kept the selector shaft from sliding out.
Now my spring that holds tension for the TV shaft was pressed inside the transmission, not sitting on the V like it should. Still had tension but either way, pay attention for that.
Pay attention to where the rooster tail selector and the valve line up. It's the furthest back valve slot, not the closest. Don't want your truck in drive while it looks in park do you?
So you're going to undo the nut as you slide out the linkage. I used one hand for the nut and another on the linkage since you have to operate both to do it quickly or just go back and forth taking your time. 
Finally the selector will slide out and you have access to the main seal on the outside of the AOD. I used a pair of needle nose pliers to pry it out. Don't grab it, just used one point, grab the handle and pry out. The pick didn't work so well on this one hence the pliers.
You can now replace the TV linkage seal (The small one you could have replaced in the beginning) since the part is in your hand.
Now put the selector arm back in and line stuff up and put the 13/16 nut  a couple turns. 
Align the guide pin and selector arm and get it in there leaving about 5mm out. Tap it in to about 3mm and if it's too far out, the pan will push it the rest of the way.
Finish bolting up the selector arm nut to the selector arm and then tighten it down. It bottoms out quick and probably needs about 15-20lbs of torque though I do not have specs. Firm cuddling not rough sex.
Install your tension spring now and make sure the lil arm that wraps around is on the outboard side of the TV rod arm where you should have seen it in the first place. If now that PDF is a good reference. Next get the long end into the V channel and it should be happy.
The TV rod that drives the valve into the body of the transmission inside will probably not look all that lined up right now. That's ok. Connect the TV linkage on the outside and tight the nut down. Suffocating cuddling, not rough sex. Things should look lined up now.
Install filter, and then the pan. If you bought that big ass upgraded pan, then hopefully you drilled your holes. If you're cutting, then I'd probably bolt the pan on as best you can now, and then carefully cut. You could also be even more intelligent and have cut prior with the old pan on.
Edited by entity-unknown

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entity-unknown messaged me with more info today!

"So yes you do have to remove the linkage and shaft.


Once I get to the point in describing removing the transmission pan, that's what all leads to pulling the linkage. It's not as complicated as the length of detail describes but I tried to be visual and cover everything.


Once I get to this point:

"So you're going to undo the nut as you slide out the linkage. I used one hand for the nut and another on the linkage since you have to operate both to do it quickly or just go back and forth taking your time. "

The shaft is out and ready to have the seal replaced. You can replace just the outside seal but that's not what is leaking, it's the inside one so it will be in vain and you'd still have to buy another o-ring set.


After that it's just putting it all together which goes real quick now that you experienced how it all works together while disassembling it."

Thank you e!


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