A4LD Valve Body Rebuild Diary | Page 9 | Ford Explorer Forums - Serious Explorations

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A4LD Valve Body Rebuild Diary

Parts arrived, and it looks like I ordered the low boost sonnax kit without o-rings.
So, should I order the low boost kit WITH o-rings, the high boost kit with o-rings or can I add o-rings to the kit I got?
2.3L Mustang that will be seeing higher HP and some boost.

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I would get the right valve Fred, and a T-5 ha ha. You have any pics of the beast?

Build Thread - off site link
Awaiting a reply from Sonnax...

Ok, Sonnax states the 4.0L A4LD Large Boost Kit can be used in the smaller engine transmissions [for] added line pressure - something I want anyway.

Working the swap.

Sounds like you're making great progress, brings me back to my old '87, came with an AOD, did the T-5 swap, had that car 17 years... stangs are a lot of fun. I vote turbo. Enjoy!

Oh, the graphics were terrible!!!

LOL, tell me about it...
Yeah, looking forward to this, lots of things that will help all A4LD owners as well as 4R44E, 4R55E, 5R44E, 5R55E/S/N/W owners. If only I could get the first gear from the 5R55S in there... [3.22:1 vs 2.47:1]

Adding the vacuum modulator to the list of parts...

Don't forget to order the Low/Reverse Servo Cover O-Rings and Cover gasket like I did.
Valve body is done but I can't button it up until the parts arrive - nothing local.
1-2 shift cover WOULD NOT BUDGE but since I was doing the Sonnax o-ringed end caps anyway I decided to drill it. Threaded a screw in threre and gave it a yank. No damage, worked like a champ.

hey guys you guys seem to know a ton about the A4LD so I hope you can answer my question.

I was replacing my modulator on my A4LD 1989 mustang 2.3 when I lost the pin down a hole where the modulator fits below where the pin enters the transmission.

I tried searcing all over with a strong magnet the trans the ground even straining the drained fluid looking for it so I am certain it went into the hole mentioned above.

How do I remove the pin? It went in the area circled in red.

I pulled the pan and I was hoping it would be in there but I couldn't find it.

So you think I should remove the valve body or something I couldnt see it anywhere. I looked all around the valve body and could not see it anywhere I Used a strong magnet to probe around and it doesn appear to be anywhere My next thought is to remove the valvebody but dont want to comlicate things further. Also If I knew where that port went It might make things easier locating it.
Failing that I am just going to make a new pin and put it back together and hope for the best.

I don't know where that passage goes either, but I'd find pictures in a manual to figure it out. Then you can better look for it. The local trans parts shops should all carry the ATSG manuals for any popular trans. Those are smaller manuals than the big OEM shop manuals, but they include almost every important picture and diagram etc.

A4LD valve body REMOVAL from trans 1991 Ranger

I have read most of the threads about A4LD valve body changes. I have the truck on ramps and the pan removed. I have the Transgo kit, gaskets, and reverse servo D-rings ready to go.
I need some very basic information on how to drop the valve body from the transmission: What internally has to be disconnected from the transmission (and how do I do it) after removing the reverse servo and cover plate? I am assuming some linkage and electrical connectors.
I am also aware of the importance of identifying where the bolts go when re-installing.
Thanks again,

Hi Tom. Concentrate on the linkage connections, the parts which attach to the VB and how they let go when the VB comes off. The electrical connectors are usually no issue to remove or remember how to reattach.

I don't think there is anything to have pop off, but let the VB down without tipping it sideways, and carefully look for the tiny valves/springs that on most Fords compress between the VB and the case. There are typically two of those, side by side, and not interchangeable. So you lower the VB, and carefully locate those types of items, noting how they are oriented, make sure they aren't hanging/sticking up in the case and could fall out. Make sure nothing is left hanging or stuck up inside the trans case, that's a regular item to do when dropping any VB.

Those are the basic items to do when dropping the VB. The biggest thing to do is be very careful with removing every part from the VB that the instructions require. Go gently, and constantly look out for the possibility of parts popping out. There are springs behind almost everything in the VB, so get a good grip of every part and tool, don't slip and let something get away. Finding those tiny parts is hard, and figuring out where they go after the fact is super tough. You can save yourself a lot of time by being patient and not having anything get away from you. Regards,

You had best get the right pin as the are a specific length and just any length won't work.

A4LD help

Thanks, Don:

You have given me lots of good advice the past few weeks. And at my age (82) I need all I can get, good advice that is!

Also, BrooklynBay and Glacier. Can't forget them and all the others. THANKS.

So after doing transgo kit. The holes in the plate i had two that were already the recommended size, one of which was the first firm 4th hole which was 0.10 over tansgos firm size? Im about to have one hell of a firm foruth i guess.

My questions on this are, the random spring in the trans, that acts as a filter. Forgot who said it in this thread, sorry. I tookit out and trans is back together, id really hate to open it again... is it needed?
Second, the actual tiny filter in the vb, both my 2wd and 4wd trans didnt have one. I dont even know where to find one.
Third, why does my 4wd trans have a huge spring on the low reverse servo and the 2wd one has no spring at all?
Foruth, the vent line, 2wd doesnt have one, 4wd does. Delete it with the 2wd plug or cut it and rpute a hose as high up as i can(offroading)?

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Thanks for this great post!

What a great tutorial for Trans upgrade.
Wondering if you have run into this problem. I have a '88 Bronco that suddenly started leaking fluid at 78,000 miles. After reading your post and an article on A4LD problems I decided to pull it myself, replace the seal and add a few upgrades. I went with the Superior Kit, Sonnax Boost Valve and oversize servo's. I also read about using a seal from a 5R55E by a forum poster who said it is a better seal and that is all he uses at his shop for the A4Ld. Well I got everything in and took it for a test drive. The upgrades worked great but after 2 miles the new seal was already leaking badly. I have not pulled the tranny out yet to see WTH happened. I've done engine seals and a few Trans seals in my time so I am not a novice.
Thanks for your input.