Fox AOD Throttle Pressure/Transmission Issues

Foxbody1987

New Member
Jul 30, 2022
8
1
1
Good Evening Everyone!

I am pretty new here but have looked around for advice and some ideas for my foxbody. My current setup is an 1988 foxbody vert. When I purchased the car, I had the AOD rebuilt and did not have many major problems for about a few months. I put about 3000 miles on the rebuilt tranny then I ran into a problem with it slipping on the highway. I took it back to the repair shop to much dismay they told me it was shot and since I added a few bolt-on mods they could not rebuild it. Got it to another shop earlier this summer and they found that the transmission was fine but the throttle pressure was not set properly. Now the transmission would not shift well and after they fixed the throttle pressure issue it ran great for the past two months. Today getting off the highway I felt the transmission slip again to basically nothing. The car was idling rough and would level out but barely anything is working again. Same issue but looking for some guidance. I can provide more details as needed and had it towed back to the same shop that fixed my throttle pressure issue. I have an Accufab throttle body as well. They did say that my throttle cable was a little frayed but to come back later this summer to have that taken care of.

Just looking for some suggestions on if this could be the same issue or the transmission itself just going again. Any help is appreciated!

Thanks!
 
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Foxbody1987

New Member
Jul 30, 2022
8
1
1
When this happened as well I was driving in overdrive on the highway. Got to the side of the road and it would limp maybe in first and second. Then it would not engage any gear at all. Finally after shutting the car off for like 20 minutes and starting up again I was safely able to get off the highway and into a business but it was in limp mode and would engage and disengage the gears. Mostly was just trying to rev.
 

junkyardwarrior

Well-Known Member
Jan 10, 2011
397
118
63
what causes slippage? Lack of pressure. The clutch packs and bands need hydraulic pressure to engage them, on AOD's they're really sensitive to this. The TV pressure actually helps get that clutch pack pressure up where it needs to be depending on throttle position (TV stands for throttle valve).

When the clutches and/or bands slip, the slippage causes a lot of heat and wear on the clutches, and it doesn't take long to fry them. I've cooked them in seconds. I believe this is what you have going on.

AOD's aren't terribly hard to rebuild but they do require a little bit of patience and knowledge in how things work inside of them. And attention to detail!

It's cooked I'm sure. But the question is what caused it, and using that knowledge is what can help prevent it from happening again.