no overdrive

[daddy_ja]

i did a search and couldnt really find much, so here is my problem. i have a 91 explorer that i just bought a few days ago. it has a 4.0 automatic. the overdrive is not working. when i bought it i was told that the overdrive has been out for awhile. i get no codes or lights, and everything else seems to work fine (other that it takes a few seconds to shift into D and R, any ideas?) can anyone point me in the right direction here? vacume lines? electrical? bad fluid? anything? thanks for any help you can give me. Ja

 

[Eneurb]

So many posibilities... not enough info... when you say the overdrive is out of it, do you mean that it just won't shift past 3rd, or it tries to shift into 4th and more or less goes into neutral?? Fluid condition would not likely be the cause of the problem, but may have led to it... how is the level?? do you have access to a trans pressure guage??

 

[agzaretzka]

When I bought mine (April), I also found the OD not working. Turned out the band and anchor had broken; drum was slightly dented. My tranny had no other symptoms/was working fine, and now even better. (Again much thanks to the members of this board for showing me how to fix it!)

 

[Opera House]

Fluid can be a big clue but generally yoy need to drop the pan to see how much sediment there is. There is a weld that break on the planetary. I've even found needle bearings in the pan and it still operated fine except OD. At least theat section is easy to get to. 3-4 solenoid can also get filled with gunk. Also sounds like you need the low/reverse servo O ring replaced.

 

[daddy_ja]

So many posibilities... not enough info... when you say the overdrive is out of it, do you mean that it just won't shift past 3rd, or it tries to shift into 4th and more or less goes into neutral?? Fluid condition would not likely be the cause of the problem, but may have led to it... how is the level?? do you have access to a trans pressure guage??

it just wont go past 3rd, it doesnt even try. im going to pull that pan today, but need to know what all i should look for. Ja

 

[Blaine122300]

What happened was this:
I was driving it in overdrive at about 55mph and when I went to step on the gas to pass, the tranny slipped into N and revved up alot, let off the gas, tried again and it worked. To make a long story short, by the time I got home I only had 1st gear.
I dropped the pan (and about 7qts of fluid) and cleaned everything up in there. While I had it opened, I put in a valve body shift kit, and a new filter.
It was like mud in there, especially on top of the valve body.
After everything was cleaned up, it ran like a new tranny again, except for overdrive. I'm thinking something with the overdrive shelled out and plugged everything up.

 

[Brain]

One way to verify a broken band is to pull off the valve body and into a cavity on the passenger's side (front) to look/feel if the band anchor is loose. If it is broken, the tranny has to be removed to replace it. You can also check for a broken band using the adjusting stud (see links below).

I had a broken band which then got wedged under the OD drum and fried everything else, so don't think that by driving it around this way there isn't more damage being done.

It could just be a bad/fried 3-4 shift solenoid. That would be the cheapest reason for it to be missing 4th gear (about $20-$30 for an aftermarket solenoid valve).

Here is a three part TSB covering the 'no 4th gear' symptom (yours has two solenoids):

http://www.alldatadiy.com/alldata/A.../34853741/34850750/42063452/42468153/56380246

http://www.alldatadiy.com/alldata/A.../34853741/34850750/42063452/42468153/42468155

http://www.alldatadiy.com/alldata/A.../34853741/34850750/42063452/42468153/42468157

Also check the 'useful thread' list in these forums for the A4LD rebuild diary (Glacier991) and the A4LD/4R55E/5R55E hybrid project (me)....the hybrid project started out as a better-than-new fix when I had a broken OD band and was going to have to replace many parts. Hope that helps.

 

[hermitrl]

My 92 needed the speed sensor replaced to get my OD back. Cheap fix if that is the culprit.

 

[86caprirs]

How did you find out that the speed sensor was bad???My X sat for 2 weeks.Then i drove it and it would not shift to OD.It drove fine before i let it sit for 2 weeks. I will have to take it apart next weekend and see what is wrong.
Will the speed sensor also cause the TCC not to work too????

 

[MrShorty]

'86caprirs: Speed sensor plays a role in both TCC lockup control and 3-4 shift control. If you're missing both 4th gear and TCC lockup, I would certainly 1st suspect something wrong on the electronic control side of things here. Speed sensor would be one possibility. various other EEC-IV sensors could also be at fault. They share a plug and a common power supply, they may have just come unplugged. 1st: pull codes from the computer (see www.troublecodes.net/Ford for a decent set of instructions), then inspect the wiring to the two transmission solenoids.

 

[86caprirs]

I can do that.....should i drive it to see if the TCC works????I drove it on the freeway and had the speed to about 120 KMH.It was in third.When i let off the loud pedal the RPM's just dropped to about 1000 RPM.Then i put my foot to it again and the RPS jumped up to 3000 and stayed in third.I guess i will have to see if there are any codes.I have not driven the X for about 2 months so i may have to give it a good drive again and then check for codes.But i will check the Speed sensor and wiring and the wiring to the solenoids.

 

[Opera House]

One easy test for the speed sensor is to see if the cruise control still works. Of course there could still be electrical connection problems between it and the computer. Another problem could be the TPS. Computer uses this to sense "demand". Even the brake switch will keep the TC from locking up.

Orig post: Was that filter you put in a black plastic and metal one?

 

[86caprirs]

Well I went to work today and snagged the NGS tester. So i will let it warm up,take it for a good run then check any codes that may come up. I have noticed the RABs light on intermitent once in a while.....so who knows.
I know the brake switch works and the TPS does to because i have reset and adjusted the voltage,checked a slow sweep for any bad spots....I hope this will give me some direction.

 

[gavin]

granted you an A4LD, but I had to get my tranny rebuilt, it wasn't shifting past 2nd.. although it started out as only having issues with O/D.
Also, there is a difference between 4th gear and O/D.

 

[Opera House]

ABS error would tend to point to a speed sensor problem.

 

[86caprirs]

Ok. so brain fart....i grabbed the cables for a ODB2 not the EEC4. I will have to wait till monday to bring home the right cables.
Well i thought it was odd that the light was on then off.....but you have to get the code while the light is on and it is hard to pull over on a freeway to find the rabs connector and check codes.....the cops hate that.
Oh well, i will let you know what i find on monday.

 

[86caprirs]

Gavin...i thought 4th gear is OD. After that it is convertor lock-up

 

[gavin]

Gavin...i thought 4th gear is OD. After that it is convertor lock-up

converter lockup = O/D

 

[MrShorty]

converter lockup = O/D

Now we are really into a terminology debate. From all I know overdrive refers to any gear ratio less than 1. For example, in the A4LD, I believe the 4th gear gear ratio is .75, meaning the the output shaft on the transmission is spinning faster than the input shaft to the transmission. Manual transmissions will have an overdrive gear, but they certainly don't have a torque converter with a locking clutch. I have always referred ot 4th gear as overdrive, with TCC lockup being something different.

 

[gavin]

Now we are really into a terminology debate. From all I know overdrive refers to any gear ratio less than 1. For example, in the A4LD, I believe the 4th gear gear ratio is .75, meaning the the output shaft on the transmission is spinning faster than the input shaft to the transmission. Manual transmissions will have an overdrive gear, but they certainly don't have a torque converter with a locking clutch. I have always referred ot 4th gear as overdrive, with TCC lockup being something different.

I guess it could depend on personal perception.
But, for example with my 5.0 Sploder... O/D off = 4th gear. O/D on = TC lockup.
that's the only reason I consider TC to be the same thing as O/D. But I also agree about the manuals... my old B2 had an Overdrive and it was a manual. So maybe it's more or less just personal perception, and no TRUE logic to it?