Hey guys, been a while since I've been around here.

I've been working on a 4.0 swap and I finally got the engine in and running (it's at my uncles, so it took forever for me to keep going over there and work on it) and I've now got a problem with the tranny not wanting to shift to 3rd gear when in drive.

Reverse seems to be working fine, and when in drive it starts in first and shifts to second but doesn't ever shift into third, I was wondering if there might be an electrical connection that got over looked, or if it just might be a tranny problem?

The tranny did get drained and I replaced the tranny filter, but when the fluid got drained it looked rather black and pretty thick, not to mention only about.. a quart (if that) even drained out.

What can I do to troubleshoot this? Or is there anything?


Edit: After doing some more research I found that after '88 the A4LD has a dual solenoid setup, before it was a single solenoid setup. In mid '88 the switch happened and the single solenoid controlled only the TC lockup function. Later models had the 3-4 shift inhibit solenoid. Would this solenoid going out have anything to do with it not shifting to anything else? If yes, how would I swap this out and where could I get another?

 

3-4 shift solenoid only effects the 3-4 shift; not the 2-3 shift. Beyond that, I'm not sure what it would be (band out of adjustment or vacuum modulator problem or governor, or valve body or ??)

 

Well that just sounds lovely, haha. I really don't want to spend any more money than I have to.

 

Could be time for a heavy-duty overhaul as well. I think if it were the modulator, you wouldn't have any shifting from 1st to 2nd, either. Not sure if the TC lockup solenoid would have anything to do with this, but might be worth looking into if for nothing more than to ensure that it's working properly. Could be that the valve body is gunked up from friction material that was in the fluid, could be a band adjustment, etc. as mentioned. I had a C4 transmission (can't remember if it was case or pan fill, but I want to say pan fill...) that would not stay in 3rd and it ended up that the clutch disks inside had eaten themselves due to low fluid level and overheating. Best bet after you narrow the problem down and fix it is to add a secondary fluid cooler for more fluid capacity and extra cooling to keep 'er nice 'n' cool.

 

Have you tried shifting it manually through the gears?

 

I haven't tried shifting manually through the gears yet, I was pretty happy just to have the thing running and by the time I was out at the house last night it was already dark (and I forgot to buy headlights.. d'oh!). I'm pretty sure that the tranny needs a complete overhaul, as far as I know, it hasn't had one and it's sitting at 192k now. I just overhauled the 4.0L that went in it so I might as well do the tranny and figure that I'll get another complete life out of this thing.

What can I expect to pay for something like this? I've read about some upgrade kits to make them stronger as well (4.0L specs), anybody have any info on this?

Thanks for all the help so far, it's much appreciated.

 

I'm not sure of the cost, but you *want* the HD rebuild with the heavy-duty parts and the extra fluid cooler. This will save you a lot of headache down the road. I would expect if it's like any of my previous experiences with a C4 auto and otherwise, expect to be paying around $1000 at the very most - then again, mechanics might be charging 'recession rates' just to keep their business afloat. I would check out all the reputable transmission shops in your area.

 

Just thought I'd check in here and give an update. I called around several places and everyone was wanting around $1200 for the HD rebuild as long as no hard parts were needed. Did a little more research and found a guy that has been rebuilding transmissions for over 30 years that works as the head mechanic at this huge Cadillac dealership here, and they give him access to the shop on the weekends for his personal projects, so I decided to go with him. He's been working on it on some nights after work and on weekends too for the past 3 and a half weeks and I should be getting my truck this weekend, and he's only charging $600.

Since it's not a DD or anything (will be once it's running again), I figured I could wait, so I saved a good chunk of change!

 

Glad to hear you're going to be back in business! Kind of figured 'recession rates' would be in effect. I had a HD rebuild done on my C4 for $750 back in the day (89-90). Hopefully, there were no computer to installed transmission mis-match issues that caused part of the problem to begin with. Let us know how she runs when you get her back!

 

If there were some of these problems, would you happen to know where I could troubleshoot that?

 

Well, as I understand things, if you have the one model A4LD with the TCC lockup solenoid and 3-4 shift solenoid, you need the right computer and wiring harness for that setup; if you have the model with just the TCC lockup solenoid, then you need the right computer and harness for that setup. My question is, are the engine, transmission, wiring harness, and computer from the same donor vehicle or same / similarly equipped year-model donor vehicle(s)? If you used your existing transmission and your BII is pre-88, then there might be a problem. Not sure how vaccum is handled for the modulator on the A4LD on pre-88 or 88 and up (if the 88 and up ones even have the modulator?), so... that might be part of it as well. The only workaround on that I can think of is figure out how to connect the modulator as it was on the 2.9 and let the computer be confused and throw codes - as long as drivability and functionality isn't affected, it shouldn't matter, IMO. Hope this is kind of the info you were asking for and that it helps.

 

The 88 and up A4ld does have the vacuum modulator(till 95 I recall) It functions just like the single solenoid valvebody. The TCC and 3-4(twin solenoid) valvebody operates just like the non(single solenoid) valvebody, the 3-4 solenoid is a override for the hyrologic shifting of the 3-4 shift point(from ECU). Just before my B2 tranny blew up the 1st time I had some LED's hooked to the wiring to watch what was going on. With no grounding to solenoid from the ECU the valve will bypass(vent) for the 3-4 will not shift up or will downshift back to 3rd gear if its in ODm same with the TCC, off is unlocked, grounded by ECU is locked.

I don't see any real problem with using a single solenoid A4ld with a duel solenoid ECU. I would get a relay(hooked just to the coils only) inplace of the missing solenoid so the ECU will still "see a functional electrical ckt". Other than that the A4ld is all hydrolic shifting points.

I have a 87 A4ld tranny(TCC only) I am probly going to stuff back in my 89 Bii just to get it back on the road while I figure out what happened to the "replacement" I installed. I learned from the Chrysler goups about the bypassing missing solenoids by using a relay's coil. The inductive kickback from the solenoid(relay coil is a solenoid!) when turned off is what the ECU looks for to verify the electronic circut. I am not sure about Ford's way of checking for open/shorted solenoids, but more likely the same as Chrysler does

 

Well I got the wiring harness, computer, and engine from a 92-93 Explorer that had an automatic in it, and my BII is a 90 and I'm using the BII's tranny that's been rebuilt.

So I read all what you guys said, but I'm confused as to if that pertains to me. Seems to be pre-88. But I'm not sure...

 

Okay, forgot yours was a '90, you hadn't mentioned that. Shouldn't be an issue with wiring or transmission configurations. As long as your solenoids are good and the wiring is good and the computer is good, you shouldn't have anything to worry about if your transmission has been rebuilt and everything is in order.

 

Ah, using a 91 to 93 explorer harness into a 90 Bii, it sould be a direct swap up to the firewall connector, may have to change a few wires around as the Explorer had a few more options than the Bronco2. Best to get a REALLY good wiring diagram of both vehicles to verify wiring of the bulkhead connector. I too though you was putting in a older A4ld into a newer vehicle.

As a side note, I have swapped a 92 explorer A4ld into my 2.9L Bronco2. It was a direct swap and for the week it did work, I seen no diffrences in the shifting or any other details that would cause problems. Then on my Wife, it failed the same as the old one did!! NO gears at all, just a whine from the oilpump area. That's after all clutch packs/Torque converter and OD input basket and one way clutch sprag were replaced!!!

If all possable get the 92-93(93 for sure) A4ld repaired as it has most of the HD parts in it allready(torrington bearings inplace of thrust washers, some of the early design flaws were repaired)