A4LD - Blown? No Rev or D, but 2nd works????

[sumless]

Greetings all,

Went to leave for work yesterday and about 150 feet from my driveway the tranny appears to have died. Drive and Reverse yield no movement, however there is noise of engagement. At first I thought the drive shaft snapped but this is not the case. Oddly when shifted into 2nd gear it will move forward. As well, when I towed it back into my driveway using my F150, even when in Netural, the rear wheels acted as if it were in park. So how bad is this?
Stats
1994 Explorer 4.0, 4X4, A4LD, about 170k miles. Changed the fluid about 8k ago, as well
added an additional cooler. No leaks. Only symptoms previous was a rather loud thunk when shifting from reverse to drive, as if the idle was too high which it was not. But that seemed to have gone away a few weeks previous as I stopped using reverse for a while.

Thoughts?
Thanks in advance,
-Joe

 

[sumless]

Guess the forums are a bit slow today. I've come to the conclusion that the A4LD Tranny is a major pain in the.. After reading tons of post regarding it I'm thinking this was the biggest weakest link in the Explorer series. With all of the other issues I seem to be having with (now three) explorers, this tranny is a common problem. Yeah, I guess I could spend hundreds of hours researching and re-engineering fixes for it, but why? There seems to be tons of fixes/mods to strengthen the odd issues that surround this tranny, but all involve a lot of time and in most cases money. I'm not a fan of spending lots of either.
Now with the Ex up on blocks in my garage, I'm really starting to wonder if its not time to junk the whole freaking thing. I've done enough work on this vehicle to know that this was probably one of the worst designs to hit the streets. Heck I had a 5.0 1989 Mustang that didn't have any problems till around 200k, and that got a ton of workouts including towing a 2500 lbs boat from time to time. Go figure. Well, enough venting for the moment. I guess I'll continue ripping out the tranny, once out perhaps a few rounds into it will relive the frustration.

As mentioned before, in Reverse or Drive a grinding sound, 2nd works find.

 

[BrooklynBay]

You could try to rebuild the valve body before doing an entire rebuild.

 

[sumless]

Thanks for the reply. My concern here is that when it stopped it felt as if there
were a distinct break of some sort. Since I am not super familiar with the
internal workings of this trans, I guess it "could" be related to the VB, but why
would I hear a slight whirring/grinding noise from both OD/D and R? Yet in 2 it actually moves without issue. I tried getting it moving from 2 and than placing
it into D (less than a 2mph) and there was a thunking and noticable stopping, as
if the main drive for (i believe they are the same) Reverse and OD/D was shot/binding up. Since I am very short on cash, I'm wondering/hoping that if it
is something internal it might be that Forward/Reverse Drum maybe?
As for the history the Tranny/driveline, I did have to replace the Autolocking hubs earlier this year, and last year (from the advise here on the forums) I added a super cooler, and temp gauge with a sensor mounted on the pan, while changing the filter. Temps never exceed 190, and more so run at a cool 160-170. Haven't towed anything, and fluid level has always been a little over.

So in short, I know no one can give me a definite answer here, is the path that 2nd takes different from the path that 1st/Reverse takes? I'm coming up empty with looking for schematics that show the internal workings of this tranny.

Thank you very much for any advise/comments.

-Joe

 

[BrooklynBay]

The Ford 3 ring blue binder, and ATSG manuals (rebuild & update) contain a lot of information on the A4LD. Many people sell them on EBay. If you are interested in learning everything about the A4LD, tearing it apart, rebuilding it, and studying its theory, then it's a worthwhile investment.

 

[sumless]

Thanks BrooklynBay.
I guess perhaps I can hit up the local Ford dealer for that info. The links that are posted within the forums seem to be failing, either from age or other. So was hoping to find something online versus spending money that can go towards this rebuild.
I do have an additional question, and perhaps there is a posting I've overlooked?
Just point me in the right direction if so.
When removing the Transfer case, one manual I have suggests (strongly) removing the front drive shaft first, any merit to this?
Also, a VB rebuild seems like it needs to be done with the tranny off the vehicle? Or is that just easier?

As well, in re-reading the write up that Glacier did for the VB rebuild <excellent reading btw>, one of the posts he has the various hydraulic flows, one struck me as perhaps pointing to the culprit, in the portion of:

<OD, Second: The manual Valve (206) directs fluid to the governor, 2-3 backout valve (211) and the low/reverse servo release side. Governor pressure increases with output shaft speeds. Governor pressure is now moving the 1-2 shift valve (204) to allow (secondary) line pressure to move through the D-2 shift valve (204) and the 2-3 backout valve to apply the intermediate band. During the shift, the intermediate servo accumulator valve (216) regulates back pressure on the release side of the intermediate servo. This helps cushion the 1-2 upshift. TCC is off.>

Could it be that the intermediate band is the only thing working, thus causing 2nd to work?

Thanks much

 

[BrooklynBay]

Getting the driveshaft out of the way is a good way to start. You don't have to remove the transmission to repair the valve body. Check the servos too. They get dried out, and start to leak because of the heat from the catalytic converter. The heat shield helps block some of the heat.

 

[sumless]

Thanks again for the reply BrooklynBay.

Ok, perhaps I've mislead or not asked the question correctly, but the trouble seems to be hardware related. I think that since 2nd is working that the intermediate band is engaging based on the fluid circuits while in 2nd directly.
Perhaps an ignorant assumption on my part but was hoping to target this before
pulling the tranny. I know (unfortunately) that I have to pull (the tranny) out to resolve this, based on the sounds its making and the way its acting.
Perhaps the heat from the Cat was causing this imitate failure into the servos, but something doesn't add up here. There should have been more warning if that were the case. Slow engagement, fluid loss, slippage, high temps, none of which were experienced and heat shield (while dirty as heck) intact.
With regard to the front driveshaft first, yes or no, or doesn't matter?
I've marked/indexed both sides front and back so as to replace them in the same position.
Also, called Ford today, the three ring blue binder is not heard of from them, perhaps another name? The spec/shop manual for this is about 150bucks but sounds like its a complete shop manual for an Ex 94. Also called Helm Pub, they want even more than that. Sheez those guyz...
I'll chase down ATSG tomorrow, but again, I'm not after a complete edu-ma-cation (lol) on this tranny, just trying to figure out the failing part.
Money is tight, so a complete rebuild (while attractive) isn't possible.


Thanks for your help.
Regards,
Joe.

 

[BrooklynBay]

Take the driveshaft out to be on the safe side. As for the manuals, type in A4LD into the search bar on EBay, and you'll see a list of parts, and manuals.

 

[sumless]

Thanks for the reply BrooklynBay.

Anyone else?