I recently swapped a used AOD into my 82 Bronco and until i get to about 3k rpm it won't move forward at all then it very slowly engages but still feels like it's slipping. Reverse engages perfectly and pulled strong uphill to the road. The tv adjustment is fine. It's 8psi @ idle, 36 with the 5/16ths shim and moving one notch tighter or looser goes out of spec. I'm afraid the forward clutch pack is toast but I'm hoping its a stuck valve not letting fluid go to them since i forgot to flush the cooler before i added 12 qts of new fluid - it was shipped dry. I'd rather not drop the pan and valve body without testing first though. If anyone has the pressure specs and procedure (ie 1st at idle with the parking brake on or Od wheels off the ground 2k rpms ect) I'd greatly appreciate the help. I've been unable to find anything about pressures for this tranny other than throttle valve pressure and how to adjust it.

 

I finally found the pressures in an online PDF of the ATSG service manual. its on the last page-96
PDF ONLINE - Ford AOD – ATSG (Automatic Transmission Service Group) (procarmanuals.com)

 

After testing i found the forward clutch pressure is just a tad high at idle (4-6psi) but i idle pretty high. However, at WOT it bounces from 140 to 172ish. chart says 176 to 195 WOT. I'm thinking either a sticking valve, a failing pump, or a blown-out piston seal but internal tranny stuff other than valve body replacements and complete unit swaps has been intentionally outside my wheelhouse for my whole career as a mechanic. Any tranny specialist have some advice? And yes i realize the clutch pack is probably toast but i don't want to fix a symptom and leave the cause to come back and bite me later.

 

Internal transmission surgery is rarely done.

#1. The transmission is very difficult to remove. If you can do a little something by just pulling the pan, then that may be doable. But experimenting and pulling the trans in and out is just not worth the trouble.

#2. Many different smaller failures can spread contaminates throughout the trans. The way the oil circulates throughout the trans, it spreads certain types of problems into other areas causing other problems. Even if you pull the trans for repair, make sure you clean and flush out the trans cooler in the radiator. Contaminates in there can ruin your freshly built trans after you re-install it.

If and when you do pull it, consider doing some upgrades to it while it is out. The AOD is notorious for being a little weak. Add a more powerful engine or larger oversize tires, or a lot of towing duties, and the AOD can give you problems. You might not be able to find a shop to do the rebuild without them installing it also. They may not warranty the trans if they cannot adjust the famous throttle cable themselves. I have run into that with other types of transmissions. There is a well known rebuilder that has videos on youtube, and it has quit doing carry out rebuilds for warranty reasons.