Weird a4ld issue need some help

[dezertranger]

Hey everyone. So I’m the new owner of a 1194 explorer limited. It’s all stock and has been a blast to drive but it’s got a weird trans issue
As stated above it’s a A4LD trans.
Shifter in the first D setting “OD”

If I accelerate on to the highway it’ll shift 4 times and drive for about 20 seconds in over drive. After about 20 seconds it’ll feel like it drops a gear. Rpm will jump up to around 3000 (55mph vehicle speed) and it will not shift back up no matter what speed I go.
Now, while cruising like this, if I shift down to the second D it’ll drop a gear (again?) and rpms will increase again from 3000 to 4000

I’m super confused in what’s happening during the first annd second increase in rpm since this trans is a 4 speed?

also, a note to add is my cruise control doesnt work.

I need overdrive to work.
Any help would be appreciated!

See pics below. Note shifter indicator position, speed, and rpm.

 

[Josh P]

I think it's the torque converter unlocking after 20 seconds. 4th gear and the converter are activated with solenoids by the ecm. I'd replace the torque converter solenoid first.

 

[410Fortune]

The a4ld is a 4 speed but also has the ability to lock and unlock the converter, this feels like a 5th shift

If you drive in d instead of od you should not feel that 5th “shift” this is an indication that the od is working

The a4ld has a “self adjusting”’kick down cable that sometimes needs to be re set for proper kick down engagement (drop into 3rd for passing is good example)

 

[BrooklynBay]

Check the vacuum line on the modulator for leaks. Sometimes the shifts could be off if there's a small leak. You could adjust the bands too. Check the fluid level. A low fluid condition could cause intermittent issues while going on an incline since it might draw air into the hydraulic system.

 

[dezertranger]

The a4ld is a 4 speed but also has the ability to lock and unlock the converter, this feels like a 5th shift

If you drive in d instead of od you should not feel that 5th “shift” this is an indication that the od is working

The a4ld has a “self adjusting”’kick down cable that sometimes needs to be re set for proper kick down engagement (drop into 3rd for passing is good example)

Only 3 shifts are felt when in D

I will look into this kick down cable I’ve not heard about it.

 

[dezertranger]

Check the vacuum line on the modulator for leaks. Sometimes the shifts could be off if there's a small leak. You could adjust the bands too. Check the fluid level. A low fluid condition could cause intermittent issues while going on an incline since it might draw air into the hydraulic system.

Thank you. I’ll check the line today and see if it’s ok or not.
I checked the fluid and I know thats good. I’ll look into how to adjust the band. Any advice on that?

 

[BrooklynBay]

Check the link in my list of useful threads for band adjustment.

 

[dezertranger]

So checked Al of the above. No leaks in the vaccum line. I pulled the line off the modulator on the trans and no oil came out so am I safe to assume the modulator is working??

Re adjusted band and kick down cable. Any other ideas?

 

[Josh P]

What size tires do you have and what axle ratio? 4k rpm in 3rd gear at 55 mph seems high.

 

[dezertranger]

I took a video of the issue, couldn’t upload here so I put it on my YouTube channel (link below)

Note how hard it “shifts” down. At the 24 second mark it looks like it shifts down twice? Maybe first is tcc and second is shifting into 3 gear? After that I shifted to second D setting and it shifted down again.

 

[dezertranger]

What size tires do you have and what axle ratio? 4k rpm in 3rd gear at 55 mph seems high.

The explorer is completely stock. Stock size tires, no lift or anything. haven’t checked to see gear ratio.

 

[Josh P]

The explorer is completely stock. Stock size tires, no lift or anything. haven’t checked to see gear ratio.

The door tag inside the drivers door will have the axle code

 

[dezertranger]

D4 axle code. 3.73 gears

 

[Josh P]

Based on the math, 4k rpm is 2nd gear and 3k rpm is overdrive applied to 2nd gear. Forgive my original guess, it appears you lost 3rd gear

 

[dezertranger]

so what do you think may be the reason for the intermittent engagement of the gear? I’m told if I have engine breaking when I let off the throttle at high speed/high rpm in 3rd I won’t have an engine breaking feel from the rpm, it’ll just coast as if it’s clutches. Mine has engine breaking. Is that correct? If so that rules out the od band.

I’m gonna change the vss today cuz it’s easy
Next probably the shift and tcc solenoid. I want to tap the pan for a temp sensor anyways so that gives me an excuse.

 

[Josh P]

I'm not an expert with the A4LD, when they leave me walking, I'll swap in a manual transmission. I'd guess fluid pressure issue since it's intermittent. If something internal was physically broken, it wouldn't engage the gear at all. How old is the fluid, and how often is it changed?

 

[dezertranger]

Based on the math, 4k rpm is 2nd gear and 3k rpm is overdrive applied to 2nd gear. Forgive my original guess, it appears you lost 3rd gear

ok so i read this post incorrectly. it does appear i lost 3rd gear. i was out and about just now and tested this theory. i put the shifter in 2nd gear and mergged on to the highwat 55-60mph was 4,000 rpm. shifted up into D "3RD" no shift no change in rpm. i shifted into OD and it shifted up and rpm dropped to 3000. so this trans can apply overdrive to any gear? im not super familiar with how this works


i checked the fluid it looked and smelled good. not sure when it was changed last i just bought this truck like 2 weeks ago. i will say the trans does look like it was replaced. the case is visually much newer looking than the t case or anything else under the truck.


i really appreciate your help

 

[410Fortune]

With the a4ld the rebuild is often when the nightmare begins
This maybe why the truck was sold to you? Botched trans rebuild

A4ld does not have the best track record
They are good from the factory but anything short of a full remanufacture by somebody who really knows these units they will never be the same again.

If you lost 3rd gear you need a new trans
Or a 5 speed conversion

If you go the new trans route…
Well you need the right Builder who won’t cut corners

 

[Josh P]

ok so i read this post incorrectly. it does appear i lost 3rd gear. i was out and about just now and tested this theory. i put the shifter in 2nd gear and mergged on to the highwat 55-60mph was 4,000 rpm. shifted up into D "3RD" no shift no change in rpm. i shifted into OD and it shifted up and rpm dropped to 3000. so this trans can apply overdrive to any gear? im not super familiar with how this works


i checked the fluid it looked and smelled good. not sure when it was changed last i just bought this truck like 2 weeks ago. i will say the trans does look like it was replaced. the case is visually much newer looking than the t case or anything else under the truck.


i really appreciate your help

Gears 1-3 are hydraulic shifted so the only feedback the ecm uses is the speed sensor, it assumes at 55 mph the transmission is in 3rd gear. The newer 5R55E uses the OD and 1st gear to create a 2nd gear that has a ratio between 1st and 2nd gear.

 

[dezertranger]

copy that guys. i thought it might need one but just wanted to rule out the cheap options first.

i bought the vehicle for dirt cheap (its immaculate other than the trans issue). cheap enough to have room for a trans rebuild before the build of the vehicle begins. soooo i guess im gonna send it off. theres a dude near by in sandiego, CA that has a good track record for building these in some old school desert trucks so ill probably take it to him.