CountryPride

I've got a 1992 f150 with the 5.0 and AOD transmission. I just did a tranny fluid swap to Mobil1 synthetic ATF. Now when I did this I also had a bad TPS. After I got done with my trans fluid, I had the fluid mark spot on with the level on the dipstick. I went to pull out of my friends driveway and the truck would not climb up the incline. It would begin to go up and the slip up into nuetral and roll back down till it was on a level surface and then out itself back in gear. This made me think it didn't have enough fluid. So I put more in and now it sits about an inch above the fill area. Went to pull out of the driveway and had no issues other than the engine miss being caused by my bad TPS. Continued on my 45 minute drive home and the trans shifted great, nice and smooth even when getting on interstate. Now today I decide to change my bad TPS. I get the new sensor in and start up the truck and it sounded great. No more high idle and the motor revs up perfectly and now sounds very healthy. I was very happy with it till I took it for the test drive. Now my tranny doesn't want to shift?? It will hold on to every gear much longer than usual and the RPM's go up higher than normal before every shift. And I now have NO OD gear. If I put it in my OD gear I can accelerate to 35 MPH and then my trans will go into nuetral until it coasts back down to 25 and then it will put itself back in gear. If I put it in regular D without OD then I can go as fast as 3rd gear limits. The trans is not shifting hard at all. Actually shifts very smooth, it just isn't shifting correctly and I have no OD. It was fine with the faulty TPS....Now isn't right with the new one?? What's the deal? I guess my question to y'all is, can having to much transmission fluid be causing my problem? I plan on sucking the excess fluid out tomorrow to see if it solves my issue, but I would still love to here yalls opinion on this matter. It was fine last night, great even. Now with new TPS its not wanting to shift and with no OD. Any help, comments, questions are greatly appreciated! Thanks in advance.

Snaggletooth

I'm not 100% but I've heard having to much fluid can cause the same problems as not having enough.

sdmartin65

I would question if the fluid is not agreeing with the transmission. I'd google search in that direction and see if others have had problems.

What makes me think that is one time we put 15w40 oil in a automatic clutch atv, would not shift right at all. Your aware 15w40 has diesel additives. Switched back to 10w40 and it was fine. Im not famaliar with mobil atf but there has to be more than one type with all the different atf's out there.

CountryPride

Well came home today and syphoned some fluid throught my dipstick hole, got the level perfect on the dipstick. Went for a test drive......problem still there!!! At this point I'm getting very frustrated with this truck, but it may be because tranny fluid tastes absolutely horrible and it has ruined my night. Lol. But, I decided to run the codes from my truck and I came back with code 85, canister purge silenoid circuit failure. I don't know what this is? Then during the second phase of testing I got codes 31-34, all dealing with PFE and EVP. I also don't know what this is about? I need help with my tranny! What should be my next move??

CountryPride

Also while its on my mind, is there anything that I could have messed up while changing my TPS that would affect my trans? I just don't know if this is my bad luck showing or if its just coincidence that directly after new motor part, I get tranny issues.

CountryPride

I've come to the conclusion that the fluid is not the issue. The level is just right and people have no report of messing up an AOD with this fluid. It has to be a sensor or silenoid somewhere. I just don't know what to be checking for this shifting problem?

CountryPride

I believe I may have figured out my problem. After some looking around online, I have found that I have a cable attached to my throttle that is called my TV cable. It is connected with my transmission and I accidently snapped the fitting on it when trying to remove it from the top of my throttle body to replace my TPS. Apparently this can be off by 1/8 of an inch and it will completely throw off your shift patterns. I will attempt to glue this piece back together tomorrow and see if can return it back to its original position. At the time I just zip tied it to my throttle so it would function. But I believe I threw it off and messed it up. Hopefully I can get this fixed. Anyone know anything about a TV cable onan AOD? Or how hard they are to replace?

CountryPride

Well I do believe I will be needing a new transmission. It will not shift at all into 3rd or OD. And I've read when this happens, it means direct clutch packs are gone. When I replaced my TPS I messed up my TV cable and I believe I fried the transmission. So incredible how a small simple cable will completely demolish your trans if not hooked up. And even when it breaks, Ford doesn't make a replacement. How smart and thoughtful of these ford engineers Both Chevy and GM make the replacement for their trucks, but Ford decided it didn't matter. So this will definitely be the last Ford I own just for reasons like these. If anyone can please help me out it would be greatly appreciated. As for now, I think my trans is toast. Anyone have experience with Ford AOD TV cables? Anything I can check to see if my trans is really 100% gone?

fordbuff91

buy a new cable first. Install it and adjust it within spec. If your transmission is ok still then problem solved. If the trans has to be replaced, you would need to get a new tv cable anyways.....

KevFord1993

Do the cable.

Also for the record excess fluid screws with the pressuring just like it would with excess power steering fluid.

It can handle a very tiny bit above normal otherwise it'll try and puke ito ut and if it can't then the pressure will screw things royally.