I am currently running a 617.951 with a 720.1 g-wagen autobox and 4.9:1 diff gears. The problem with the current configuration is the 4 speed auto's 4th gear is 1:1 thus I turn great amount of RPMS at highway speeds and returning terrible fuel economy (13.6MPG, not to mention I cannot hold speeds about 50mph climbing slight grades, forget about a dead stop!). I have been tossing around the idea of a OM603 swap for more power but would still be in the same boat if I used the 4speed that came bolted to those engines. My question is would a 722.508 5-speed autobox from a W126 300SE bolt to the OM603 and if so, how is that transmission operated? Does it use a transmission control module or does it use vacuum hoses and cable? Thanks for your help.

All the 5-speeds are computerized 1996+ models. Supposedly there is a standalone controller available for around $700, but I haven't looked into it.

Thanks for the reply. So then a 5speed auto from a 89 300se would be manually controlled. But does it bolt up to a 603 block?

Also you can get a GPIO controller that runs MegaShift with Megasquirt. A fully configurable transmission controller for not much money.

(02-24-2010 07:04 AM)bmw4aaron Wrote:  Also you can get a GPIO controller that runs MegaShift with Megasquirt. A fully configurable transmission controller for not much money.

I'd like to read more about the megashift controller but info appears to be hard to find. (I couldn't find any info on the GPIO sites and having the same name as some christian movement doesn't help.)
(Edit: Ah, finallly found it: http://www.msgpio.com/manuals/mshift/index.html )

It looks like it is designed so it could run on it's own (without megasquirt) and would use the rack position sensor, MAP (boost?) and speed as inputs (all easy to get)
But it looks like it only works with 4 speed transmissions so back to square one.

more info - looks like like 722.6 and megashift is possible but would require a little legwork to get it going.
http://www.msgpio.com/forums/viewtopic.php?f=4&t=88

Seems there's enough interest on this forum of people wanting 5 speed transmissions to make something like this happen.

-Christian

If anyone can give me a description of how to operate these solenoids to make the transmission shift properly, I'd be very interested in working on a controller for it.

http://www.startekinfo.com/manual/volume..._3/p21.pdf
http://www.startekinfo.com/manual/volume..._3/p23.pdf


Sensors/power/ground are pretty obvious. I'm guessing the modulating pressure valve operates similarly to the vacuum modulator in the older transmissions, and that the torque converter PWM valve is used to control how tightly the torque converter is locked. Do the shift valves cause up or down shifts, or both? And how do you control which direction it shifts? (Maybe shift pressure valve??)

Any transmission experts out there? Someone donate me a 722.6 to develop on I have yet to find a single one of them in the yards...