Frustrating transmission problem.

[alajokir]

I have a 1992 ford explorer 4x4 that has been giving me hard times. well only one since i bought it when it needed repairs.

I originally bought it to go camping/fishing while still having a warm space to sleep without needing a tent without the gas tag of hauling a camper.

Its gotten to the point where i piked up a 76 f250 to go fishing but I still want to fix it. So I've taken to anywhere on the net that will listen in hopes of finding an answer. Here is "basically" what I say each time, this being the newest one and to a member here (with a small change).

"Hi, I was looking through google for a solution to a problem I'm having with my explorer and you seem to know quite a bit about the a4ld. I was hoping you could help me.

I have a 1992 ford explorer xlt 4x4 with the v6/a4ld combo and and the transmission will not engage into gear. I bought it off a friend who thought it was the transfer-case but didn't have the time to fix it himself, it was a reasonable price but after changing the transfer-case it didn't rectify the problem.

I then thought that the transmission may have been the problem, but after replacing it with one from a vehicle that drove but had no breaks the problem still was not fixed.

After that I tried changing the transfer-case control modual thinking it may have been in neutral, and after nothing I then changed the main cpu from the passenger side kicker panel and still no results.

Having asked other people about this I will also include the following information:

Torque converter was also from the donor vehicle.
Engine revs to 3000rpms but it doesn't seem like the transmission is getting any power.

Is there anything you could suggest that may be the problem? I'm only used to working on older vehicles that are usually manual so all the electronics and inner workings are unknown to me.

Thank you in advance for anything you may suggest. "

In closing, ANYONE who can help or who thinks they know the problem DO NOT hesitate to answer, I'll try anything up to but not including a seance. If you've had this problem before or know someone who has, PLEASE give ANY advice you have or put me into contact with someone who can.

This vehicle has so much more to give, It'd be a shame if I end up crushing it.

 

[Tbars4]

...If you search on here, there is a lot of tranny info to be found...Good luck with your project...

 

[BrooklynBay]

Welcome to this forum! The sticky threads in the transmission section have a lot of information to help you with your problem.

 

[MrShorty]

Engine revs to 3000rpms but it doesn't seem like the transmission is getting any power.

It really sounds like something is out inside both transmissions you've tried. There are really only three things I can think of outside of the transmission that would explain what you are describing: transfer case in N (which would allow the truck to move even in P, because the wheels aren't connected to the transmission at all), broken differential, or maybe the crankshaft somehow got sheared off so nothing is getting to the transmission. Since none of these scenarios seems very likely, I'm going to say it's something in the transmission.

It's not an electrical problem, because the A4LD isn't dependent on anything electrical for basic engagement like you are describing. The A4LD does use electronics to control a couple of things, but even without, it should shift 1-3 without problem.

I'm not good with diagnosing the internal mechanics of automatic transmissions. It seems that one of the usual first tests in a case like this is to test transmission fluid pressure. It seems that someone here posted some basics of where to test at, but I don't remember.

Be sure to check fluid level. You might disconnect a hose from the transmission cooler and briefly run the engine to see if any fluid is pumping.

 

[BrooklynBay]

# 10 in my list of useful threads has information on testing hydraulic pressure. Check the vacuum line from the modulator to see if it's leaking fluid. Some shifting problems are caused by a bad modulator. I'm going to move this thread to the trahnsmission section for you.

 

[alajokir]

quick question

just a short question before pouring through all the information here, what do all the plugs/connections do?

since I swapped out the transmission from the torque converter to the drive shaft from a vehicle i drove from the front of the house to the rear, I know they all work.

I know that the speedometer cable is the one with the bolt on retainer, but there is the vacuum line, two electrical plugs and the cooler lines.

speedo only says how fast its going. the vacuum lines weren't plugged when i took them off. could the master cylinder have caused it? or a clogged inter cooler?

Could something be broken in the rear diff? I know that when I lift the rear tires the drive shaft will turn, but not with any power. I've stopped it with my hand. so I couldn't see it.

*edit*

Q3. I am lacking the 4th gear shift into OD. (The so called 3-4 shift)

A3. In the A4LD, the shift from 3rd to 4th (or the so called 3-4 shift) is controlled by a solenoid. In the majority of cases wherein there is a 3-4 shift lacking, either the solenoid has problems, the wiring to it has a probem, or a screen on some models may be plugged up. Checking the wiring and for voltage at the main feed wire to the solenoids is a first place to check. Many times lack of 3-4 will also have a lack of Torque convertor lockup too. This can add heat to the trans, and the common lack of 3-4 and TCC lockup usually is a good sign of an electrical issue, as neither solenoid is operating correctly. Often this issue may relate to the wiring harness to the PCM (computer). [Brooklyn Bay adds the following good observation: The PCM takes sensor inputs from various places, such as the Vehicle speed sensor, Brake On/Off switch, and Throttle position sensor
to calculate when to apply a ground signal to the A4LD's solenoids to apply or not, or in the case of the Torque convertor clutch to lock, and unlock. Often, there could be a driveability problem due to one of these solenoids because of a bad input to the PCM from one of these sensors, and it might be mistaken for a solenoid problem when in fact it is not.]

would an electrical problem lead to the torque converter not locking up? if so how would i test it and or rectify the problem?

 

[MrShorty]

would an electrical problem lead to the torque converter not locking up?

Yes, but the computer won't command TCC lockup until 40'ish mph (3-4 shift seems to wait until at least 30 mph). Perhaps I've misunderstood the problem, but my impression from your original post was that your truck wouldn't move at all. There's nothing electrical in getting the truck to move. will it move in any position (R,D,2,1)?

Could something be broken in the rear diff?

Yes, but I expect this would be pretty obvious: Drop it into gear and the rear driveshaft spins (probably even registers on the speedometer), but the wheels don't go.

 

[alajokir]

when i drop it into gear nothing moves, unless I have the rear axel supported, in witch case at idle in any gear but reverse the tires will turn, but very slowly and with no power.

I cant see it being past two things, one being that there is no fluid flow. either the torque converter isn't doing its job or there is a block somewhere. but there wern't any metal shavings in the oil when i dropped the other tranny. or two something electrical. since the eec seems to have an if string in it where (from what I've read in other posts) "if such and such happens before such and such then apply power to somewhere or other"

could the break on off switch do anything? or a broken wire anywhere along the harnesses making it think something is happening thats not supposed to?

I asked about the rear differential because I dont really know if it seased back there if it would limit drive shaft output. because it seems harder to push than i expected it to be, my old standard ranger had to be push started more than once.

I'm trying to limit the areas of possible problems because im still working on the f250 and dont want to have 2 projects in the middle.

 

[MrShorty]

or two something electrical. since the eec seems to have an if string in it where (from what I've read in other posts) "if such and such happens before such and such then apply power to somewhere or other"

could the break on off switch do anything? or a broken wire anywhere along the harnesses making it think something is happening thats not supposed to?

With an A4LD, this is not a possible explanation for "no go" You could take all the electrical out of the vehicle (if you figure out how to get the engine to run without it), and the A4LD would behave like a traditional 3 speed transmission. The only things that are electronically controlled are the 3-4 shift and TCC lockup, both of which only come into play after going.

It's true that there are many all electronic transmissions out there (E4OD, 5R55E, 4R55E, and so on) for which "no go" could be something electronic. The A4LD is NOT one of these transmissions. So, in terms of eliminating possible problems, we can eliminate electrical/computer stuff.

For a "no go" like this, we have to look at something hydraulic or something mechanical. Maybe you didn't get the torque converter seated onto the input shaft right. Or maybe the filter came out so that the pump can't pickup fluid. No fluid flow is definitely a possibility. Maybe the bands aren't adjusted right. The mechanical/hydraulics are not my strong point, so I'm not really sure how best to approach it. There's been talk of checking pressure. It would be easy to check for flow at the cooler.

 

[alajokir]

well, it'll need to wait for a bit to test the pressure, though the torque converter not seating right is a possibility, i seem to remember buying a lot of beer that weekend.

i suppose i could pull it and give it another shot.

any suggestions for improving the odds of a good sync?

 

[BrooklynBay]

Keep rotating it while it keeps jumping another notch closer into the bell housing. A torque converter that isn't fully seated will most likely leak, and grind away as soon as the motor starts to turn.

 

[ALARMIST]

Since you drove the doner vehicle, the trans was 'known good' but now shows the same problem as the old one.
Make a list, don't check the item off untill you are sure, then put that one out of your mind, then move to the next.

1st - when you moved the trans/ converter, from the donor to your vehicle.
Did they separate or move? If so did the pump drive slots on the converter get lined up and seated in the pump?

I'm hoping you had the converter in the trans during install, if it was bolted to the flex plate on the engine, I don't think you could feel the engagement of the pump correctly and could have sheered the pump drive
while bolting it all together. Did it slide right together or was it difficult the last 1/2" or so with a sudden snap into place as you tightened the bolts?

2nd- ask the seller if you got it in the same condition as it was last driven.
could the flex plate be wrong? could there be the wrong spacing so that the converter no longer engages the pump?
Do the flex plates look the same? old / donor
Did you put the bolts in the torque converter? (sorry, have to check each link)

3rd- the shift linkage? don't assume anything (work safe here) the trans worked, now it does'nt - disconnect the shift mechanism, shift the trans
directly - you should be able to feel PARK REV NEUTRAL DRIVE ETC.
You could have a some piece not shifting correctly or out of adj. turned around or broken.

4th - if all is good so far, then engine- converter- pump are spinning and
gears can be selected manually.

How much fluid did you remove/ spill? How many qts did you put in?
should hold roughly 10-14. once you are sure its full, remove the cooler lines
from the cooler, run in gear, should pump some fluid into a pail.
If not then it's internal.
If it does pump, then it's moving fluid, make sure it flows thru cooler, reconnect lines.

5th- you mentioned changing the t-case, is that all correct? When in PARK
is the rear drive shaft locked from spinning.

Good luck

 

[Jack Flash]

I know this is probably not the problem...but I have run into 2 transmissions where someone else installed them &...

...the input shaft was left out. I don't know if the person pulling the tranny dropped it, accidently left it out, or who knows what...

people, me included, make mistakes when we are tired & frustrated.


.
.

J...happy hunting