1994 a4ld failure

[Iaintknowdawg]

Good afternoon guys.

I've got a 1994 Explorer XLT who's transmission failed about a month ago. The backstory is it overheated in August and lost a bunch of fluid but ran fine after a top-off until November. In late November a trans cooling line leaked right before the intercooler. I repaired that, and all was well until mid December when the transmission crapped out. I was leaving work (it ran fine in the AM), and it slipped out of first and started rolling backwards into the lot.

Right now it'll go into gear and move a little bit, but has almost no torque. It's the same with reverse or low.

I'm trying to figure out what on the transmission has failed so I can determine if it's worth repairing or replacing the transmission entirely. I tried searching but my google-fu is weak, and I couldn't find any posts with a similar problem.

Thank you

 

[JK080]

What ever has failed in the transmission will require you to remove it and take it apart to get to it, so I wouldn't worry about trying to figure out what happened at this point\. You should inquire about having it rebuilt or replaced and make the decision on which way you want to go from there.

If you have it rebuilt at a transmission shop you should have a warranty in case problems arise you can take it back to them and let them fix it. If you replace the transmission yourself and have problems you will have to diagnose it and maybe have to pull it back out and send it back to have it fixed. I recommend having a shop fix it for you, it's just less hassle for you in the long run. Good luck and let us know what happens.

 

[BrooklynBay]

Welcome to this forum! How many miles are on it? Did you replace the internal filter (not just the fluid)? Did you connect a 0 - 300 PSI test gauge to the test port to take pressure readings in each gear? It sounds like the hydraulic pressure is low. It might be due to a broken pump gear, leaking O ring seal on the filter, bad valve body gasket, loose valve body bolts, worn cluck packs, clogged or worn valve body, bad boost valve, etc. Did you check the fluid level when it's cold then again after it warms up?

 

[Iaintknowdawg]

Hey ya'll-
The explorer has 642,000 miles on it, the transmission has about 450k since it was rebuilt. As far as I know, the transmission was serviced (whatever that means) around 500k by the last owner, and it's probably overdue for a filter replacement.

I have replaced the fluid, but not the filter. I'll work on getting my hands on a test gauge. The fluid is clean, and there's hardly any metal shavings on the magnet so I don't think any hard parts are busted. I checked all that when I rebuilt the top-end of the engine in June.

Can the valve body and filter stuff be performed without dropping the transmission? I've done a little transmission work on a 700r4, but that was out of the vehicle at the time.

I can do a lot of stuff myself, but seeing as almost all my car maintainance ends up being done on a gravel driveway under a tree, pulling a motor or trans might be a bit out of my capabilities. I'm trying to get it running again myself, moneys really tight right now, but if I can't I'll take it to a pro after tax return season.

Thank you

 

[410Fortune]

642K!! Woweeeeee whomever rebuilt that trans my hat is off to them since it went almost another 200K
Yes the filter and valve body are accessible with the pan dropped
Good place to start
see if anything looks out of the ordinary
Before you drop the pan though take note of these:

Fluid level when warm, in park on level ground?
Does the trans work if you force 1st gear?
How about second?
Do you have reverse?

 

[BrooklynBay]

The filter & valve body are serviceable with the transmission in the vehicle. You will see them when you remove the pan. You have gotten incredible mileage out of that transmission so don't be surprised if it needs to be rebuilt.

 

[Iaintknowdawg]

Awesome- thanks guys. I'll try to drop the pan tonight and take some pictures.

Fluid level when warm, in park on level ground?
-retconning this section due to stupidity
Does the trans work if you force 1st gear?
-yes
How about second?
-yes
Do you have reverse?
-yes
To all over the above-mentioned as long as you don't try to go into drive first. Once you try to shift to drive, it returns to doing nothing in all gears.

I've done a bit of searching and it almost sounds like the torque converter, but I can't find a straight answer on what a torque converter *actually does* and what its failure might mean. Thoughts?

The trans rebuild was done by my uncle in 2004, I've no idea what he did to it exactly because by his own admission he was p*ss drunk and doesn't remember. He put about 500 dollars in parts into it, and says he remembers doing some drilling. I'll see if I can dredge up the parts receipts. He then put about 350k on it before he gave it to me when he lost his license. He worked in oil fields out in Texas and racked up crazy miles on it. Since I had it its life has mostly been as a general use farm vehicle.

 

[410Fortune]

So he probably replaced the hard parts and updated the valve body

Maybe buy him some beer and put the A4LD in front of him again?
I will ask my trans builder about your dilemma here today and see what he thinks

 

[BrooklynBay]

Reverse gear has more hydraulic pressure so that's why it's a little stronger than the other gears. The torque converter fills with transmission fluid, and has internal clutch plates similar to the rest of the transmission. The TCC solenoid will engage & disengage in a similar fashion like a clutch in a manual transmission configuration. The torque converter will disengage while you're parked or at a light. The engine will stall if it's always engaged, and you are not moving.

 

[Iaintknowdawg]

I did some troubleshooting over my lunch break based on your questions.

Fluid was a bit low from what I think is an intercooler leak, so I topped that off. Maybe a quart down.

So it looks like when stone-cold, it'll go into 1, 2, and R fine and I can drive around the parking lot. Plenty of torque, I can spin the tires and everything. It will not go into D or OD, and once I try to go into D or OD it just whines and will not engage any other gears. It stays like that till I set it sit for a few minutes, then I can repeat. Until I try to put it in D or OD. I guess I didn't catch this beforehand because my MO was to go straight into Drive first, then try the others.

Fluid looks good to me. Attached pic is after the top off, warm, in Park on level ground.

I updated my above post to correct my mistakes. I'm sorry about that and I appreciate your patience.

Video
https://ufile.io/ivxlk

 

[Iaintknowdawg]

Update-

So I think I got it fixed-ish. It's shady as hell, but I was able to get it to engage IN DRIVE.

I drained most of the fluid via a bleeder attached to the transmission cooling line, then refilled with synthetic ATF. It would kick into R, 1, and 2 a bit more readily after this.

From you guys posts, I developed a theory- if everything works but D and OD, maybe it's the valve body? I mean, the gears clearly engaged, so it couldn't be the gears themselves, it had to be the thing that TOLD the gears to engage and when.

So, I had a coworker sit in the car with it on, with the rear wheels blocked, and cycle through the gears with the brake on, while I hit the bottom of the pan with a hammer. After some swearing and hammering, the whine stops and THUNK, into first gear. We did some testing around the parking lot, use 4x4 and low range, etc, then took it out on the road with the coworker tailing me. It made it 5 miles to my MILs house.

Based on ya'lls feedback above, I'm going to attempt to rebuild the valve body using Glacier991s valve body rebuild diary.

Thank you so much

 

[BrooklynBay]

Check the hole for the z link in the manual slide valve, and the z link to see if it's bent. They become oblong after a while so the gear settings might be slightly off.

 

[CDW6212R]

With that mileage since built, it will be naturally in need of new frictions and steels. The VB is the control of all functions, and there is just one VB kit for the A4LD. With that kind of mileage, that VB is also nearing it's end of life. The bores and pistons will be well worn and leaking internally a good bit.

That being said, do what you can to get it to work for as long as possible. But I wouldn't invest more big money and time into that trans. I'd replace it with another A4LD, and be sure it gets all of the possible VB updates, solenoids etc.

I still own my spare 93 trans, and engine, both with 112,622 miles on them. If you were closer, I'd make you a good deal for it/them. I'd take $100 for the A4LD, it worked fine when I took the truck apart to build my 99 with the body.

 

[Iaintknowdawg]

The explorer made it 45 miles on 11E last night. It still has trouble engaging D and OD after starting, but if I go into 1 or R first, then into D it works OK. Once I'm moving it just does its thing.

There's a bunch of other work I'd like to do on it before returning it to regular road and farm duty, like the control arms, mounts, and putting some plates on the frame, but IT MOVES.

CDW6212R- Knoxvilles only about an hour and a half from here, I work in Kingsport. Let me see about borrowing my FILs pickup and I might take you up on that. Any idea where I could get a brush guard for an explorer this old?

You mentioned the valve body, is there any other work you'd recommend be done on it before installing it? I'd have to pay somebody to actually put the transmission in, so I wanna make sure it's tip-top before I get to that point.

 

[410Fortune]

synthetic ATF? Be careful here ytour transmission was designed to use Mercon and it should stay that way, using other fluids is asking for trouble

If you are going to pay to have the transmission replaced, do just that. Pay a reputable transmission builder to R&R your current transmission and give you a warranty.
Otherwise remove the unit you have, open it up and plan to do a FULL rebuild, a new /updated/rebuilt/valve body, and a new torque converter

 

[Iaintknowdawg]

I used Valvoline MaxLife Synthetic Transmission Fluid from Oreilleys.

It had Dex/Merc on the bottle, but should I drain it and refill with non synthetic?

 

[CDW6212R]

Ditto on the fluid, that should be a synthetic compatible with the original type. I'm not sure about if the synthetic Mercon is the ideal choice, I need that answer myself for my AOD's(which were Type F fluid) in my Lincolns. I've had the old B&M Trickshift for those for a long time. Just for sure do not use any kind of Mercon V, or any later ATF versions, those are too slick for the older transmsissions.

My 93 A4LD has the VB kit in it and worked great. It's still 26 years old, it should be rebuilt. But the bad about these was the high mileage wear on the hard parts, not the normal wear items(clutches/seals). So mine with a normal rebuild should be good to run another 200k+ depending on usage. Towing with these was a bad idea, I'd bet your truck was always normal driving duty.

I'd double check on new Sonnax VB upgrades, they add things occasionally. My two A4LD's I did the VB work in 1999-2000, both same TransGo kits and new solenoids, plus a longer modulator pin, which improves the 2nd gear shift. It's about 1/8" longer than stock, began as a Chrysler pin.

For a rebuild, you have to plan on the normal seal/clutch kit, new torque converter, new solenoids, VB items, plus unseen internal hard parts damage. That high mileage A4LD I admire and would be grateful to, but I doubt it will go another 100k with a rebuild. Mine is the kind you want to find to rebuild, not high mileage and never burned up.

 

[CDW6212R]

I used Valvoline MaxLife Synthetic Transmission Fluid from Oreilleys.

It had Dex/Merc on the bottle, but should I drain it and refill with non synthetic?

That's the Mercon(1) I'd try, I think Mercon was recommended for all early 90's Fords.

 

[410Fortune]

as long as it is mercon compatible (not Mercon V not mercon LV) you are good in the A4LD, Valvoline is some good stuff

It sounds like your A4LD would be a good candidate for a rebuild since it is still in semi good working order and the fluid is pink with no metal bits

 

[Iaintknowdawg]

From what's going on, I think the valve body was gummed up or my fluid was shot. What do ya'll think?

There's not any metal shavings and no crud in the fluid that I removed and it smelled about like the stuff I put in. The old fluid was noticibly a lot more runny. The cooling line had plenty of pressure when I took it off the intercooler to check, it shot a nice, strong stream of dexmerc directly into my face.

I'd still like to rebuild it so I've got something reliable to work with. Most of its life since I've had it has been hauling feed, taking stuff to the dump, pulling stumps (low-range is strong like bull), and towing around a johnboat. If I can get my hands on a cheap A4LD to put in, I'll have this one swapped and work on rebuilding it. If it's shot, it's shot, but I figure I can learn a lot from gutting it.

If I'm gonna depend on an SUV that's older than my wife, I aught to learn how it works.