mongolchuck

91 lx vert 5.0. Supposedly has a rebuilt aod with shift kit. Fluid is new and full. I can start it up pop it in reverse and it will go. Let it warm up some and reverse no longer works. It feels like its in neutral. Forward works fine no matter the temp. I've looked all over and people have similar problems but they never post what fixed it. I have set the TV cable. I've read about the servo but was wondering if there were any people who have had this problem and actually fixed it and what fixed it.

aode08

This is a very old and very common problem,USUALLY THE TRANNY TECH TORQUES THE VALVE BODY BOLTS ONCE.

Drop the pan and check your valve body bolts.
Bet they loosened up, if they did, your going to have to replace the gaskets and re-torque the bolts, 3 TIMES

Personally, the guy that rebuilt it would be getting it back,it totally sucks I know.
The techs are good at re-using parts that look good,especially seals that are not included with a cheap overhaul kit,it how they make money, however, you cannot do this with a AOD.You need the expensive overhaul kit.

mongolchuck

OK dropped the pan. There is a little fine material in the pan and on the magnet. I think its from having to rev it some to back it out of the garage. The fluid is clear. The valve body bolts were tight. I took the valve body off and checked the servos. Pulled the reverse/first servo and it has been replaced. Servos and covers are cheap so I want to replace those. Here's the question: the servo I took out is a single groove and therefore I should replace it with a single groove; but what if the original replacement was the wrong one? What is the difference between the three reverse/first servos? How do I know which one is the correct one?

mongolchuck

The more I think about it I'm doing what I hate; throwing parts at something without knowing the exact problem. I keep thinking maybe the band or clutches are worn. Looks like I'll be pulling it out and tearing it apart. I'll pick up an overhaul manual but anything in particular I need to look for? I've only had experience rebuilding t5s.

mongolchuck

Well after a lot of other stuff getting in the way I finally took apart the aod, replaced the reverse piston seals and got it reinstalled. It has reverse! This was my first time tearing into an aod but it isn't as scary as people say it is. Got the seals in without the seal protectors too. Just have to go SLOW and use lots of lube (that's what she said.) I know this is an old thread but I don't like reading threads were there is no resolution.

88 orangepeel notch

Thanks for the update, glad to hear you've fixed it. Congrats

Now we just have to work on your repair speed lol.

chav84gt

really late response to this thread but i have came across the same issue recently. would a complete rebuild kit take away this problem?. i have seen this master rebuild kit on rockauto for about 150 and have watched youtube videos on disassembly.

Urambo Tauro

If you've already ruled everything else out, like fluid and shift linkage checks, then yes, the problem is going to be inside the transmission and a rebuild kit will have what you need to resolve it (as long as you don't discover any "hard part" failures upon disassembly).

wbrockstar

I know little about aod transmissions,so this is the reason why Im asking the following questions.Were there internal hard part failures or case damage in/to your original aod that caused you to have to buy a rebuilt transmission??Are the parts you replaced yourself,& any you've got the experience to replace,a far less complex job than whats normally done during an aod rebuild??If no,I was just curious why you didn't do a rebuild on your original aod vs buying a rebuilt aod,since you seem to be experienced enough to work on one?? If I knew how to rebuild t5's or aods,that would be a great little side job to have.Any idea what the typical labor charge would be for each trans type,to do a standard rebuild?? Thanks for any insight you can give.

Urambo Tauro

Can't speak for the other fella, but shops in my area want around $1500 to do a AOD/AODE/4R70W rebuild. I decided to do my T-bird's 4R70W myself, which cost me nearly half that, IIRC. Full rebuild kit, torque converter, new direct drum, spiralock ring, OE-style reusable pan gasket, fluid, cooler flush... My actual final cost gets a little muddy from there, because I put some of the money I saved into tools, since I didn't have a clutch spring compressor or a bearing/bushing driver. I also treated myself to a parts washer to make things easier. So I must have spent more than $1000 in the end.