This is not truck related but you guys are the best. I have a 1991 Thunderbird with a 5.0 and AOD with 198,000 miles on it. The tranny has been shifting perfect. Today, I drove the car about 275 miles and when I got close to home and stopped, when I took off, the tranny did not want to shift. It would race up to about 4500RPM before it would change any gears. I pulled over and checked the throttle valve bushing which was ok, it has been replaced with the brass one. Checked the fluid and it is full and red. Got back in the car and the same thing. I drove on home and tried adjusting the throttle valve which seemed to help the problem although it would occasionally hold gears too long. Now, the car has sat for about three hours and now it won't shift out of first at all. I'm scared i'm going to blow the engine if I run it any harder. ANy input would be appreciated!Perhaps sticking governor? If it were an A4LD I would know what was wrong but i've never had any problems with an AOD. And no! The car has not been run with the TV disconnected.

 

It sounds like something is slipping - with almost 200k, it's probably time for an overhaul. No transmission will last forever!

 

Well, I have decided that it is in my best interest to pull the tranny and see what has happened. I have ordered a master kit and converter that will be here this afternoon. This will be my first time to be inside of an AOD but i'm not scared. I have the factory service manuals and have sucessfully rebuilt several A4LD's and C-6's.
I have all the essential tools of the trade so it should be finished by Monday. I don't think it is burnt up though. I am going to do a pressure test on it first to determine the extent of the injury. I think something has went wrong with the valve body, perhaps a stuck valve or loose valve body because the throttle valve feels normal with spring pressure at the tranny and the problem occured suddenly rather than slowly. The tranny has not been slipping... I would have known that... and 200,000 highway miles is not that much for a well taken care of AOD that has had frequent, complete fluid drainings its entire life. I have had the car since I got my license in 1993 and my mom bought the car new in 1991. It has never been rawhided by me although it has seen its share of high speed highway running and jack rabbit starts its entire life. The 5.0HO is a lot of fun to drive even in stock form!

 

the cable could be broke.you could of lost tv pressure and burnt up the trans due to no line pressure increase when the load increases.this happened to my 90 s/c t-bird.

 

If the cable was broke it would seem that it would not have spring pressure when you pull on it with it disconnected from the throttle body. I have not rulled out that something may have come loose in the tranny. I need to look in the service manual to see how it is connected in the tranny to the valve.

Aaron

 

Update!

This morning I decided to get started on my T-Bird bright and early. Left the house at 0700 and made it about one mile with the tranny stuck in first when it decided it wanted to start shifting. Drove it on to the shop, got in my other vehicle and drove to NAPA and got a case of fluid, a bottle of Lubeguard and a filter kit. Went back to the shop and drained the converter which looked good and smelled like near new fluid, dropped the pan and found normal wear deposits in the pan. Actually, this was the first time it has ever been serviced because it still had the plug for the dipstick in the pan. I was amazed at how clean the unit appeared... looked like new. There was a normal amount of black clutch material in the pan with only a few speckles of metallic material. This was also the first AOD I have ever seen that did not have a magnet in the pan.
I put a magnet in the pan, refilled with fluid and put the Lubeguard in. Took it for a spin and it now shifts better then ever with no delay. I beleive that being the pan did not have a magnet in it, some debris had a valve stuck in the valve body causing the stuck in first problem and the delay in shifting. I surely hope that the problem is solved. I will update in the morning when I take it for a spin from a dead cold.

Aaron

 

Well, the tranny was doing fine until I let it set for a week without being ran. I actually put about 700 miles on it after the service with no problem. The stuck in first until it warms up is back. Guess it's time for a rebuild. At least a re-seal and valve body service. I wish Stuart would chime in on this....

Aaron

 

Disconnect the cable at the top and pull it out as far as it will go several times.
Reconnect it and do a test drive.

Some times the inner throttle valve gets stuck.