to rebuild or not to

[ccf1]

I'm trying to get people’s opinions on this A4LD AOD transmission problem-even though I still may rebuild the thing, since it’s on an old Explorer.

This happened almost two years ago, but in the beginning of the breaking down of the transmission, when going in reverse it would have a 3 or 4 second delay before engaging. This went on for a month or so by itself, with no other problems. After that month or so when on the interstate, intermittently, it would only go up to about 45 mph. I guess it wouldn’t go from 3rd to 4th when in overdrive. Sometimes I could put it in drive, and it would snap out of it and reach normal speeds. I drove it minimally and dropped the pan to change the fluid and filter. Upon doing that, I lost all function of the transmission. Recently I’ve been working off and on with prepping it for removal and rebuild. This afternoon I got to the part of loosening the bolt holding the bracket with the metal vacuum line providing pressure from the manifold to the diaphragm, and noticed that the short rubber hose that goes from the end of the metal tubing to the vacuum diaphragm was missing. I found it lying on the side of the transmission, close to the heat shield.

My guess is that when I loosened the heat shield to move it out of the way-in order to remove the pan for the fluid and filter change, I accidentally further removed an already barely hanging-on rubber vacuum hose--leaving the transmission with no pressure at all from the manifold. I also noticed that the inside of the hose was covered in hydraulic fluid, which probably indicates that the vacuum diaphragm was failing, or no good at all. I’m just wondering if maybe the intermittent 45 mph top speed and hesitant reverse was merely due to not enough vacuum pressure, and then finally no pressure at all, leading to the complete loss of forward and reverse. I know it’s an old transmission (’92) and I would like to have the experience of performing a rebuild, but it’s almost tempting to put everything back together and get a new vacuum diaphragm just to see if that’s all that the problem was. But with my luck, it would have only been part of the whole problem.

Any suggestion or opinions from anyone?

 

[35Remmy]

CC...I'd be REAL tempted myself...Honestly, I'd wait for one of the moderators like Glacier to chime in...the guy seems like an A4LD expert. He'd be able to tell you exactly what would happen w/o the hose in place.

 

[ccf1]

Thanks for your response Remmy...anyone else out there have a suggestion?

 

[Glacier991]

the 45 max speed sounds strange. You didn't say what the rpms were. That sounds like something different than you are thinking. Like not shifting past 2nd gear. 3rd will run you at highway speeds - the rpms will just be between 3000 and 3500.

You also didn't say anything about total miles on this tranny, and fluid changes, or current fluid condition.

It is possible your lack of a connection to the modulator has caused your problems, but maybe in conjunction with other things... difficult to tell. Easy enough to replace the line and see... unless you are well along in the removal, in which case, and depending on miles you may want to do a rebuild along the lines of the A4LD Rebuild Diary.