I have a 92 explorer with a A4LD tranny. If I put it into gear it will only go about a foot. Could this be a shift sensor problem or some thing bigger? Also how hard is it to rebuild it yourself? I have a mechanical back ground but never messed with a automatic tranny.

 

You need to try it in all the gears and post results. D is not the same as OD in first gear for example. How it operates in manual 1&2 and reverse can tell a lot. Getting it out of the vehicle is the hard part. The rest is easy if you pull it apart slowly and label everything. You can even do a partial rebuild. I've written some procedures.

 

My '92 Ranger has the same tranny and had the same problem. It was fixed by simply changing the vacuum modulator. The part is on the outside of the case. It costs about $25. Since mine was due for a trans service (fluid/filter) anyway, I took the truck to a trans shop (DO NOT have the local Jiffy-lube place do this repair!) and they did it all for $125 including the new part. Problem solved. They said it is a common problem on the older transmissions. Hope this helps.

 

I had the same problem with my Trans but when they replaced the diaphragm they forgot to reinstall the little rod that is behind it and due to this I VERY quickly burned out my trans. Now I need a complete rebuild

Make sure that who ever does the swap of the diaphragm is aware of the little rod that connects to the diaphragm and that it will fall out during removal.

How did I know that the rod was not in place? I went back to my mechanic and asked him if he reinstalled it during the process. He looked at me like I had two heads. We then took a look on the lift where he did the replacement and found the rod sitting where it had fallen. Upon removal of the diaphragm the rod was missing.

Unfortunately he is my friend and has et me use his garage for many repairs on weekends and at nights so I can not get to mad. He has offered to remove and install a new Trans for me for free. Now I have to find a Trans or rebuild the one I have.


Dean

 

The vacuum modulator changes the speed the transmission shots at based upon the load of the engine. A high load on the engine results in low vacuum, hoghest vacuum is at idle and when your foot is lightly on the gas. The vacuum modulator will not prevent a vehicle from moving.

 

dsmith1484..... take a look at Jasper. I had a 92 that I had to replace the trans on.... only cost me $2200 for a new trans.... plus it came with a 3 year/50,000 mile warranty. It was pretty much a no-brainer when I was getting rebuild costs of $1600 - $1800.

 

On my '91 I learned the following: (The hard way.)
If it ever back-fires, it can blow the diaphram in the modulator. This allows a good deal of the trany fluid to be sucked out. To check for this pull the vacuum line to the trans. and look for fluid in the line. If not found in time this will allow you to burn-up your overdrive box.
I replaced my modulator and the missing fluid but the damage had been done. OD shifting was gone. If I put it in OD I could not go nowhere.
If I put it into D gear by jumping over the OD position I could drive as if nothing was wrong. Even slipping into OD above 35mph and back out of it at before getting under 35.
Solution was to rebuild or replace. Local shop wanted $1800 to rebuild it and offered a 3 month warranty. Ford has the rebuilt ones for $1300 and a 3 year warranty.
This is what happened to me. I hope yours is easier.