What model Trans swap from 722.3 to 722.6
 

Hey,

so im really tired of my 1994 sl500 having to go about 2.5k rpm to go 75mph, and i would really like to swap a 722.6 (as far as im concerned my car shifts by vacuum and has no electrical control unit) from a 1996 or newer. My question is, right now im looking at either an e class or s class from a local junkyard, would those work?? The oldest one i could find was 1997 from an e320, and there are some s420's that are 2000, and an e420 from 1998. Basically would any e or s class tranmission control and wiring harness of any engine size work with my sl500? Unfortunately there are no sl320-600 in the junkyard so the next best thing would be the e and s . I would obviously take all the necessary electrical components but before i go up there is it possible?? Since my car does not have a transmission control unit i feel like there would be no way to wire power to that unit, and maybe im in way over my head. Can anyone give insight??

p.s. yes i know a 320 420 or 500 s or e class has different shift points and transmission calibration than a 96 or newer sl, im not worried about that and please dont mention that as im aware.

Can anyone give insight, yes stop telling us what you know and start telling us what you don't know like an understanding of the non vacuum 722.6 and its TCM and its relationship to the engine control module(ECU)------wada you learn???

The 722.6 is supported by data it sends and receives over the controller communication network. I suppose none of your cars existing modules will communicate with new transmission.

Perhaps you should sell your car and try to find a '99 or newer car to replace it.

yah..thats what i am asking about.. can the 722.6 hookup... ive already re done alot of my sl500 so i guess i should have also mentioned that getting a new car is not an option and i do this as a hobby and i am able to do 98% or more of the labor myself. Yes i understand the tcm and ecu and how they link.. again..thats why i am asking whether or not a 722.6 could possibly be theoretically fit in a car with a 722.3.. Ive had half the people tell me the 722.3 has no tcm and only uses vaccuum to shift and a few others tell me there is some kind of a tcm under the passenger footwell..idk maybe its not possible and would require too much work. Sounds like im answering my own questions.. plus i know the car switches from obd1 to 2 in 96 which is also the same year of the 722.6 so if my car does not have a tcm then it would require a whole re wire of the entire car and obviously im not going to do that as that is a waste...

lol welp..my questions have been answered