Moparts

control A999 converter lockup

Posted By: BcudaChris

control A999 converter lockup - 10/10/17 08:52 PM

I'm switching to a built A999 w/lockup in my 73 Barracuda. does anyone know of a way to automate the lockup engagement/disengagement? I'd like to NOT have to manually operate the feature with a toggle switch.
Posted By: Supercuda

Re: control A999 converter lockup - 10/10/17 10:36 PM

Lock up is not electrically controlled.

There are versions with an electric unlock solenoid that was used in certain HD applications to prematurely unlock the TC, but if you do not use it then it will function like a normal LU A999. Have you tried just driving it?

I would wire in a WOT switch and let that toggle the unlock if you want to keep it functional.
Posted By: John_Kunkel

Re: control A999 converter lockup - 10/11/17 12:38 AM


Lock and unlock are controlled on A999's with the electric input. A pressure switch connected to the governor test port will lock the converter when a certain road speed is achieved (10 psi governor pressure is about 10 mph). An adjustable vacuum switch in series with the lockup switch will unlock it at heavy throttle.
Posted By: BcudaChris

Re: control A999 converter lockup - 10/11/17 03:17 PM

Brilliant! The vac switch/oil pressure switch setup is how 700R4's work, is it not?

THanks
Posted By: Magnumguy

Re: control A999 converter lockup - 10/11/17 05:52 PM

I thought on A999's that the lockup was actuated by line pressure/etc. You can buy a spring (at one time anyway) to control the speed of lockup.
\
Posted By: 135sohc

Re: control A999 converter lockup - 10/11/17 06:30 PM

Originally Posted By Magnumguy
I thought on A999's that the lockup was actuated by line pressure/etc. You can buy a spring (at one time anyway) to control the speed of lockup.


Around 86 or 87 the lockup function gained electronic control. I have an 85 A999 and it is non electronic.
Posted By: 383man

Re: control A999 converter lockup - 10/12/17 01:46 AM

As far as I remember all the A999 tranny's were electronic lock-up. The first lock-ups were hydraulic but I dont remember any of the hydraulic lock-ups called the A999. From what I remember all A999's used a solenoid controlled by the PCM to control the lock-up converter on factory tranny's. Ron
Posted By: astjp2

Re: control A999 converter lockup - 10/12/17 05:47 AM

Not the 999's out of my 94 and 86 jeeps, all manual lockup.
Posted By: John_Kunkel

Re: control A999 converter lockup - 10/12/17 11:03 PM


A999 was introduced in '74, lockup in '78 and electric lockup in the mid-eighties.
Posted By: 5thAve

Re: control A999 converter lockup - 10/15/17 02:34 PM

Depending on application. The ones in M bodies were non-electronic right up to the end of them.
© 2024 Moparts Forums