I just recently purchased a 1988 Ford Bronco II. As far as I know it has the A4LD transmission.

The problem I am having is that when the vehicle is cold reverse works fine, but when the vehicle is warm, like at the grocery store the other day, I could engage reverse for one or two seconds and then nothing. I had to push it out of the parking spot.

Could it be the modulator valve or could it be the seals inside?

I am trying to avoid high repair costs as much as possible. Any input would be helpful. Thanks.

 

I would first change out the low/reverse servo piston O ring. There is supposedly an updated "double lip seal " that replaces the old O ring. If this doesnt fix it,then your probably gonna have to go into the trans. Might be the apply piston seal is bad.

 

What is it and where is it?

Thanks for the advice.

 

The servo can be accessed by removing the oil pan.It will be located in the right(passenger side) rear corner, if you are looking straight up .It will have a steel cover over it. The cover is somewhat square, with a round center, and will have four bolts,one in each corner.When you remove the cover there will be a spring and piston under it. The piston will have an O ring or might have a seal type O ring on it.This is what you need to replace.