What is the interchange on speed sensors for 440-T4, 4T60E, 4T65E

Looking at replacing the 440-T4 in my 85 DeVille with either a 4T60E or 4T65E. I need to retain the VSS signal from the speed sensor in the governor housing. Are they compatible? If not, are they interchangeable? I may change gearing, or factory tire sizes may be different, etc., but I need to keep the signal.

On my Jeep its a simple job of moving the sender assembly from your old transfer case to the new transfer case. From pics I've seen it looks like its mostly the same with the transaxles but I want to know more

Thanks

I think your existing transmission is shaft driven speedometer vs the 4T60-E, 65-E electronic speed sensor which is not shaft driven but electronic.

thats what i would guess, i know for sure they didnt use electronic speedo and vss in Fbodies till 87. take a look at your trans should fairly easy to see if its wires or a cable.

seems to me if you want to keep the engine it has, a 700r4 with a mechanical speedo would be a better easier swap. they are essentially the same exact trans. its just operated by a throttle cable and vacuum modulator instead of a computer.

nevermind was thinking this was rwd, not so easy i guess. why you want to change the trans?

The 440-T4 speed sensor is a gear-driven thing with a 2-wire connector in the governor assembly--if you change tire size or something then you replace the little gear with a different tooth count to change the number of pulses. The signal is used by the ECM for TCC lockup, and also fed into an analog circuit that feeds the speedometer needle gauge.

On 4T60E and 4T65E (I think) the signal is generated by a reluctor gear and a magnetic pickup.

I am trying to figure out if the pulses are signal compatible (same number of pulses, same voltage peak, etc), or failing that are they interchangeable so I can move the speedo and/or governor assembly from the 440-T4 to a 4T6XE. After thinking about it last night, I doubt they are interchangeable because the 440-T4 requires some kind of mechanical input on the little plastic speedo gear, which is probably missing from the 4T6XE. Or maybe its possible to move the speedo drive from the 440-T4 over to the 4T6XE and interface that way.

Is the reluctor doing vehicle speed from the axle speed (after the differential), or from output speed (before the differential)?

I need to figure out where the 440-T4 signal originates as well. I am pretty sure it is vehicle speed since the FSM only talks about amplifying not modifying the pulses.

I know somebody I can ask, thought you guys might know

My 440-T4 has to be removed for repair. I'm under no obligation to put another 440-T4 back in the hole. I am looking very closely at putting a 4T60E or 4T65E with an independent TCU and only have a few integration issues to overcome for it to be a green light (speed sensor output being the main one at the moment).

I will share more information soon, as of right now I'm just researching to see what'* possible.

Per this post, the OSS from 4T65E is signal compatible with 440-T4 VSS

That'* a great thread btw, my inspiration, but I'm definitely not doing HD swap

Transmission swap about to start - 440T4 > 4T65E [Archive] - A-Body.net - 1982-1996 GM A-Body Forum

seems like a whole lot of work, for not much gain.

could be said about performance work to most GM cars from mid-80s and later

am I in the wrong place?

just my personal opinion, i am all for modifying things. all my cars have some level of modification, but it was for some benefit that was worth the trouble. please correct me if i am wrong but seems like you are trading one 4spd with OD to another 4spd with OD. with alot of added hassle. if there is some other benefit let me know as i dont really know that much about FWDs in the first place