Help Swapping a A4ld for Blow C3, 84 Ranger

[pa84-Ranger]

Hello, first post. I've been reading all I can but haven't found the answer yet to my problem.

Here's the details
84 Ranger, 2.8L engine
blow C3 Trany

I'm swapping in a rebuilt 86 A4LD I got for cheap.

I'm planning on swapping in some longer shift linkages and a OD shifter using some junk yard donors. I'm not sure if this is the way to go yet but I also plan to swap the gas pedal to use the cable style kick down off of the gas pedal.

But here is the question? How do I control the Torque Converter Lock-out. Will my existing EEC-IV computer do the job (the C3 doesn't have OD) or do I need a later year model. Can I use one from a donor with a 2.9L or 3.0L engine. I could use a relay to the two prong switch on the Trany if I knew the pin out from the EEC ( I think It pin 52-53 but not positive). I'm worried the EEC from these other engines won't control the 2.8L engine correctly.

I'm not thrilled with the pressure switch or the vacuum control methods I found, I'm worried about the tranny hunting between 3 and OD. Any help or advice would be great

Thanks

 

[pcollins]

IF your putting an A4LD in there, make sure its rebuilt to just about new condition, and then take GOOD care of it. Those trannies are notorious for failing if not maintained.

 

[piotrsko]

for the torque converter, why not use a lockup kit that does the external user lockup> Summit has one, i think, just a 2 wire connector on the side of the tranny and a switch and a power source.

I'd also think that the computer from a 89 probably will work as I used one from an 84 on my 2.9

 

[pa84-Ranger]

pcollins

Thanks for the advice about the a4ld. There are lots of horror stories in the forum about these. The c3 I'm taking out, I know is shot and needs a total rebuild, the a4 is in working order and appears to have been rebuilt in the not to distant past. I like the idea of having the Overdrive. so I'm going to use the A4LD as long as it works. I only paid $20 for it from an owner who did a V8 conversion on his truck. He's a Mechanic by trade so I'm hopeful the trany will last awhile. It's still cheaper then trying to rebuild the C3.

 

[pcollins]

pcollins

Thanks for the advice about the a4ld. There are lots of horror stories in the forum about these. The c3 I'm taking out, I know is shot and needs a total rebuild, the a4 is in working order and appears to have been rebuilt in the not to distant past. I like the idea of having the Overdrive. so I'm going to use the A4LD as long as it works. I only paid $20 for it from an owner who did a V8 conversion on his truck. He's a Mechanic by trade so I'm hopeful the trany will last awhile. It's still cheaper then trying to rebuild the C3.

thats a good deal. My stepdad had a late 80s ranger with the A4LD, we got over 100k out of it, so as long as you change the fluid every 2 years and never beat on it (i.e-offroading) it should last you a long healthy life!

 

[pa84-Ranger]

piostrsko
I'm hopeful a latter year EEC-IV computer will work. I grabbed the unit from the donor truck with a 2.9L (mine is 2.8) where I got the longer linkages. I also nabbed the wire harness with the male plug end I need to make up the connection to the TCC plug on the trany. I believe the pin out for the trany lock control is pin 53 so if the Computer runs my engine ok I'll try wiring the control to the TCC thru a relay.

As for the lockup kit. I read about this in the Duraspark thread. My understanding is that it taps into and monitors the trany governor pressure. It uses this signal to energize/de-energize the torque converter lockup override, normally done using the computer. Seems simple enough, but the transmission already uses this pressure to lock the torque converter up internally using a hydraulic circuit. So this seems to me to be redundant and I'm having a hard time understanding how or why this provides any real difference in control. That is why I'm leaning toward doing the computer control method with a computer designed to supplement this control.

The vacuum control method also seems to be a redundant control circuit sort of. I'm not sure how the vacuum modulator interacts with the lock up. My concern is hunting between 3rd and Overdrive.

If anyone has some feedback on how the pressure switch works and or how the vacuum switch works for their truck or if they can shed some light on the matter I'd be interested in hearing it.

Thanks

 

[piotrsko]

people smarter than me will probably make me see the error of my understanding, but: A4LD are basically a c-3 with an overdrive stuck onto the front. C3's were basically internally pressure controlled for upshifts and etc, so hence the modulating with a vacuum source on the a4ld. the computer on an early (83 to 88) a4ld is just along for the lock up, it has no real control over what is going on internally. The 89 and later has proper control over the trans including shift points and lockup. OTOH, properly set up and adjusted A4ld's don't hunt up and down, because they are too simple and you don't have this huge V8 band of torque. BTW ford provides pressure via the valve body and a solenoid on the a4ld is what diverts pressure into the TC to lock up. without the solenoid energized, you have no lock up.

I used the 84 computer in the 89 because someone said it would not run on the manual trans. Looking at the wire harnesses, the 84 seems to be pretty much the same as an 89 except for some color changes and stuff like the EGR that was deleted in 89. I can't see why a 89 wouldn't work in an 84 or an 86. you will have to add a wire out of the trans harness connector for the lock up option, but if you have the harness from the donor vehicle, you'll be good to go since I think it is there in an 84 or was in my 84 parts car.

finally worse case is that it might run rich until the O2 sensor comes online, but I found that the injectors were pretty much the same on 2.8 and 2.9