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Hopefully some of you AOD experts can answer a question...

I bought a used AOD and I'm in the process of installing a shift kit. The guy I bought the trans from said it was working fine in the '89 F150 it came out of - was a daily driver before it was wrecked. The transmission has not been installed yet.

I had no problems with the valve body upgrades but have a question about how tight the OD band should be. Part of the shift kit upgrade has you remove the OD servo to put a washer under the piston. I made sure that the servo pin was correctly lined up with the detent in the band. When the servo is pushed in, I can see it move the band so I know the pin is touching the band. The shift kit instructions say the band should wiggle about 1/16". On this transmission, the band moves about 1/4". Is this too loose? I'm trying not to have to rebuild the trans.

Thanks!
 

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That does sound a bit on the loose side. There are different length piston and apply pin assemblies used for setting band clearance. Check which one you have and get back to me.

Don
 

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Discussion Starter #3
Don - Thanks for the reply. I know I have the B servo and the Transgo kit adds a washer under the piston. I'm not sure about the pin length. How can I check?
 

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Oops, my mistake. Confusing the OD servo pin with the Low/Reverse. The OD servo is a long travel servo. The washer is placed where it is to cut down the response time of the servo apply. I think if you check the instructions, it says with the washer installed the band should wiggle back and forth 1/16th of an inch, meaning it shouldn't be any tighter than that. You should be okay.

I would, however install the "A" servo from the Super Coupe.

Don
 

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Discussion Starter #6
Don - that makes sense. I need to replace my Low/reverse servo and I knew about the grooves to identify the length. I don't know if the A servo will make a difference - just going to cruise in the vert once it's running. Do you notice much of a difference with the A servo?

88cougarGT - I read your write up and it seems doable. Since I don't know the exact condition of the trans I will probably go ahead and order the new band. I just ordered a couple other parts from Bulkparts. I couldn't open the pics in the other board. Could you attach them here?

Also, is there any way to tell if the pump is good? Since it is probably coming out I could repalce it if needed.

Thanks for all the help!!
 

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Cross Post:
Since no-one responded I thought I would Give an update.

Yes, this worked great.
I also replaced the seals on the OD accumulator piston and the 1-2 shift piston as these were old and hard as rocks. The procedure was actually pretty easy. Just remember, this will only fix the slipping OD gear. Like I said, my 1-2, 2-3 and even the 3-4 shifts were crisp, but the OD Band wouldn't keep stay engaged. I parked the car immediately. If you keep driving it, the excess heat created will eventually fry all your remaining seals and kill the trans.

It looks long, but its not all that hard. Just make sure you work in a CLEAN envoronment and lube all new seals with plenty of fresh Mercron. My total outlay was around $100. Rebuild kit was around $45, the OD band about $12, $10 for a new filter, and about $40 in Mercron. Not bad for a fully functioning trans.

How long will it last? No idea. Like I said, other than the OD band, it worked great, so hopefully a long time. If you ask me, $100 to get you going again for even just another year is probably worth it (I'm super cheap), especially if you don't have the coin to drop on a full rebuild.

Materials:
Basic Rebuild kit (gets you all the gaskets you need and then some) Bought mine from here: Bulk Part – Welcome to Bulkpart Transmission Parts and Transmission Coolers Their prices are great and they ship lightning fast.
OD Band, 1.5" for 1992 and earlier, 2.0" for 1993 and later.
8 qts of Mercron
Huge drip pan.
3 bolts that fit the front pump.
Set of snap-ring pliers (or two small flat blade screwdrivers)

1. Remove the Trans from the car, drain and store the Torque Converter.
2. Get a huge drip pan from wallmart and flip the trans on its back on the pan.
3. Remove the front pump bolts.
4. Go to the parts store and get 3 bolts that thread into the front pump (not the case, they are larger than the case bolts. They are also metric).
5. Rent a slide hammer and 3 jaw puller. I used the one with the retaining ring to make life easier.
6. Remove the pump by threading the 3 bolts into the pump housing. Attach the slide hammer to the 3 bolts (one at time) and slowly tap the pump free with the slide hammer working in a circle.
7. Carefully remove the pump and set aside. KEEP EVERYTHING IN ORDER.
8. Carefully remove the intermediate clutches and steels. KEEP IN ORDER.
9. I Was then able to reach inside and unhook the OD Band and remove it since it was really loose. Should end up looking something like this: (Borrowed from 4R70W Rebuild Diary - Part 12 - Assembly up to Intermediate clutch - Ford Explorer Ranger Enthusiasts "Serious Explorations"® an Excellent Reference).
DSCN7040.JPG

10. Remove the trans pan, and unbolt the valve body and gear selector detent. Put the valve body aside.
11. The big servo in the middle is the reverse. Closer to the front of the trans is the OD piston. Remove the snap ring on the OD Piston and carefully work it out of the bore. Its easier to push it up from inside the trans where the OD band was attached.
12. Clean the OD Piston and bore with brakeclean. I used a scotchbrite to clean bore and give it a dull sheen. Replace the gaskets on the OD piston and bore with ones from your kit.
13. Soak the new OD band in ATF for a couple hours. Then work it into place inside the trans.
14. Push the OD Piston assembly back into the bore and make sure the OD Band is hooked on the guide pins.
15. Re-Install the snapring. This took considerable effort and I had to have a friend help push it down while I installed the snapring.
16. (OPTIONAL) replace the 1-2 piston seals. These come out the same way as the OD piston. But, you must use a thin piece of paper to keep the seals compressed as you re-install the piston.
17. Clean the paper gasket off the front pump, careful not to get any into the pump ports. Replace the big rubber o-ring on the pump.
18. (OPTIONAL) I replaced the torque converter seal at this time because it was easy, and came with the kit.
19. Inspect and re-install the intermediate clutches and steels. Should now look like this: (Again borrowed from 4R70W Rebuild Diary - Part 12 - Assembly up to Intermediate clutch - Ford Explorer Ranger Enthusiasts "Serious Explorations"® )
DSCN7067.JPG

20. Align the pump and carefully slip it into place making sure not to scratch up the seals on the pump. Align it carefully and torque it into place using the pump bolts.
21. Make sure no crud made it into the valvebody. Then Locate the lower valvebody gasket and install it into the trans.
22. Install the valvebody and torque per the attached PDF.
23. Install the Shifter Detent.
24. Install a new O-ring on the fill tube.
25. Check filter screen for debris, clean if necessary. Install fresh filter and gaskets. Re-install pan bolts and torque per attached PDF.
25. (Optional) Flip trans back over and replace the tailshaft seal.
26. Re-install transmission. Fill and check level. Set TV Cable. Test drive. and enjoy having OD again.

Valve Body Bolt length and Torque Pattern: Bolts.pdf

Big thanks to the the Explorer forum for the 4R70w Rebuild diary. This is a great read as the AOD is very similar.
4R70W Transmission Rebuild Diary - Ford Explorer Ranger Enthusiasts "Serious Explorations"®
 

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Thanks for reposting this. Do you also recommend installing the A servo?
If you can source one from the JY cheap (theres an SC at my local lot right now with an AOD). I've heard that at a minimum you should run the B (found in trucks/mustangs). Are you running lots of power through the trans? Do you think the trans will last?

Here is some good info on the servo. Internal Upgrades Specific to AOD Transmissions - Baumann Electronic Controls, LLC

I read somewhere that a good shift kit and a B servo is generally good for a mild 302 with some upgrades in a light vehicle. I wish I could find it again. Also, generally you should avoid full throttle 3-4 shifts and that your TV cable is adjusted properly. That's what ate my band.
 
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