PINTO CAR CLUB of AMERICA

Welcome to FordPinto.com, The home of the PCCA => General Help- Ask the Experts... => Topic started by: waldo786 on April 20, 2014, 02:04:31 PM

Title: computer controlled trans?
Post by: waldo786 on April 20, 2014, 02:04:31 PM
I am looking at putting an a4ld overdrive trans into my car, and understand that I will need to have a switch to turn on the overdrive.  I was wondering if there would be a way to use an ecm just for the trans?  It looks like I am going to be keeping my engine carbed so I would only need the computer to work the trans.  Anyone with ecm knowledge know if that would work?
Title: Re: computer controlled trans?
Post by: RSM on April 20, 2014, 06:21:26 PM
If memory serves me correctly, all the ecm did was work the lockup on the converter. I had a 1988 Mustang LX with that transmission in it. I bought the car as a basket case. The PO said he was having tranny issues and pulled the original and replaced it with a salvage yard unit. His issues didn't go away. He started to pull it back out and stopped, leaving it as is. I bought it from him that way and put the car back together. His problems came to light very fast. The car would actually stall as soon as I accelerated. Took me a while to figure it out but the ecm was causing the converter to lock up right away, killing the engine. I unplugged the wire from the transmission and my wife drove it like that for a year. The lockup is good for around 300 rpm or so on the highway. Didn't make much difference without it. About a year later the transmission started slipping and I swapped it for a T5. Once i pulled the A4LD I found out that the locknut on the high gear band had come loose. That cause the adjustment on the band to loosen up and caused high gear to slip. The transmission was still good and I sold it. Long story short, while 300 rpm would be nice it doesn't make a massive difference for fuel mileage, if that's what your after. If you do a ton of freeway driving, you could always install a toggle switch to work the lockup. Just remember to turn it off when slowing down lol. This is just my opinion for what it's worth. I'm sure someone else will chime in.

Title: Re: computer controlled trans?
Post by: amc49 on April 20, 2014, 09:42:18 PM
A simple brake pedal switch would turn it off. An rpm or limit switch of some type could turn it on.

If you use a PCM, the unused things may well fail into a limp mode and mess up the whole thing. You'd have to use the PCM on everything to have it not signal a problem.
Title: Re: computer controlled trans?
Post by: jeremysdad on April 20, 2014, 09:52:05 PM
A simple brake pedal switch would turn it off. An rpm or limit switch of some type could turn it on.

If you use a PCM, the unused things may well fail into a limp mode and mess up the whole thing. You'd have to use the PCM on everything to have it not signal a problem.

Brake lights on, lock-up off. That's preicsely what I was going to say earlier, but didn't. "Toggle" is way overated when you can switch on/off with the brakes. Toggle is for city driving. lol
Title: Re: computer controlled trans?
Post by: 74 PintoWagon on April 21, 2014, 10:26:06 AM
"Toggle" is way overated when you can switch on/off with the brakes. Toggle is for city driving. lol
A toggle switch is not just for city driving it works great on the freeways too, it's almost like another gear. Friend of mine has a 700R(built for power) in his pickup that he tows his race boat with and on small hills he'll kick the lock-out off and the r's come up a bit taking some of the load off the motor instead of dropping a gear and have the rpm's go way up and have to slow down, I'm getting ready to build mine and I'll be doing the same thing, lock-up will be strictly on a toggle switch.
Title: Re: computer controlled trans?
Post by: waldo786 on April 21, 2014, 10:32:54 AM
Didn't even think of that but those ideas are great!  Sounds like I don't need to worry about the lock up if it only affects about 300 rpm.    I am curious though, is that bad for the transmission if it doesn't go into lockup?
Title: Re: computer controlled trans?
Post by: 74 PintoWagon on April 21, 2014, 10:39:33 AM
Under lock-up the fluid will be cooler, has no effect on the tranny itself, most trannys out there don't even have/made for a lock-up converter.
Title: Re: computer controlled trans?
Post by: amc49 on April 21, 2014, 08:02:20 PM
Most of the trans fluid heat comes from the converter SLIP.
Title: Re: computer controlled trans?
Post by: 74 PintoWagon on April 21, 2014, 10:10:51 PM
Torque converter is a fluid coupler, anything under the stall speed causes more heat, when it's locked up it don't use fluid to make the connection..
Title: Re: computer controlled trans?
Post by: amc49 on April 28, 2014, 08:52:52 PM
Amen, brother.
Title: Re: computer controlled trans?
Post by: rramjet on April 29, 2014, 12:56:18 AM
Have a 200 4R in the wife's 50 Chevy. Guy who did the work is old school and just put a toggle switch in it. I added a vacuum controlled switch that takes converter out of lockup on acceleration. I've never needed the brake switch. I don't run the lockup around town just for freeway driving.
Title: Re: computer controlled trans?
Post by: 65ShelbyClone on April 29, 2014, 10:45:40 AM
If you need something that can control all the converter and shift solenoids in a fully electronic trans, there's the MegaShift transmission controller based on the MegaSquirt GPIO hardware.

http://www.msgpio.com/manuals/mshift/4L60e.html