The full powershift Magnum was a further refinement of the 5x88 series three range 18 speed. Syncro tri six I think they called it. The early Magnums even had IH cast into the cases.

Then the sales team at Ford wanted to be the first to produce they type of tranny, so they pressured everyone into building them asap, despite the engineering department insisting they weren't ready to go on the market yet. Harold Brock insisted they were going to be a disaster, jumped ship (most folks say he was forced out for refusing to approve the SOS design for production). He then got hired by Deere and was one of the chief engineers to work on Deere's powershift, and later the head engineer for Deere's entire tractor line.

That's the story as it's always told, anyway. I'm sure there are other facts, and the sales team at Ford would tell a much different side of the story.

I have read of lots of failures in the originals, then they came out with a series 2 made in Mexico, then they just went away.

Joe was the tranny engineer and struggled with getting the power shift unit into production. The only ran it in 2 - 7030-50's for testing beside the test stand. Besides loose bolts and flyball drillings and tolerances for seals and a few other issues corrected by 1978 (1976 was the first offering - called the small filter unit) the units were as dependable as one could expect. Joe struggled with gear ratios and went around the country in 1977 with E.W. (Swede) Muehlhauser getting feedback . He wanted to offer different ratios for different areas but the bean counters nixed the idea. He was not satisfied with the 1-2 shift spacing and mentioned closing up the ratios with a 3 speed rear shift but there just wasn't enough room w/o a housing change.  The size of the clutches were a hold over from the power director housings - in some cases 10 times larger than competition.  Just ramblin...    

Lars, that was Case-o-matic.

 Doc, had a fellow in the neighborhood that had 2 6000 Commanders Select-O-Speeds.   he did lot of custom work with them, from plowing to chopping. and everything between. He loved those tractors. Dad hired him to chop one year because it was so wet that we couldn't get out in the field with our heavy Papec chopper with the WD45 hooked onto the D17. Just get off the headland and we were stuck.  Ol' Beckmark said he would be right over at 2 and he came into the yard and out to the field and turned off the head land and the front end went sliding, he toed the brake to bring it around and that tractor just grunted and started blowing black smoke... OOps he had left the brakes latched together for road travel and when he took his foot off the brakes, the wheels started spinning faster and was now sliding faster down the hill sideways and the snoot  of the chopper hit the the sidewall of the Firestone tire and about 50 gallons of chloride went fly everywhere. What a sight, over the chopper, in the chopper box and even over the tractor and even ol Bill got wet. He never stopped, he pointed that tractor right up the hill and back to the headland. We got the wheel off and Bill took off and got a new 18.4 Good Year .  We get it on and looking... and he got mad, cuzz that GY was smaller in width and height. But he wasn't taking it back.  Fired up that 6000 and went to chopping right out there in the standing water in places, where we couldn't move. He had a little cylinder cut Ford chopper rated for 2-3 plow tractor and he would stuff that chopper full and be running down the rows cutting the stalks off at angle cuts with about a foot of stalk left behind bent over. I took a box out with the D17 and was running near him

on the hayfield in 4th low and he came to a low spot in the field and tyhe corn got shorter and that Commander had 3 grunts of smoke come out of her and I couldn't catch up to Bill with the throttle wide open on the 17. Splish splash, mud and water squirting out from under them tire flying everywhere, wish I had a movie camera back then. Another time, He had turned the pump up on them and was doing some custom plowing and the DNR spotter radioed to one of his buds and told him to tell Bill to turn those pumps down some because it looked like there was a fire where ever he went.  He didn't like the DNR and when that agent left, he shifted up another gear, and then the smoke really rolled. Reason he did that was the EPA/DNR had the county take their injectors of the old graders and send them in to be recalibrated and when the pumps came back, they were cracking head and Bill didn't want his grader's head cracked so he cracked the seal and gave them some fuel to cool on.   

 Seems to me there was a fellow that I had talked to many a years ago that worked on the Ford select-o-speeds, Think it was a Palmer Fossum. We had talked about a 921(?) Diesel Ford select-o-speed I bought and he said he would help me with getting it going. He could make those transmissions work almost better than new, but the fellow passed away before I got around to fixing it. Maybe will never get it fixed now.

  Oh yea, 25-30 years ago some guy bought Bill's Commanders and a few years ago I was to an auction and looking at a gray/blue 6000 Commander and it looked like Bill's but it was not sitting on 18.4 tires, but a smaller size like 15.5 or 16.9 and I started talking to a fellow about Bills old tractor and he said This was his tractor but it needed tires and he didn't like the cost of the 18.4 so he went smaller.. LOL

Wonder what Joe Heopfl could have accomplished with his idea of a larger sized (transmission? rear end?)housing for his 3 speed rear shift request?? So by 3 speed rear shift, would it have converted the 12 speed PS to an 18 speed(6x3) or 36 speed(12x3) in 1978?  Interesting that prior to the 7000 series, AC heavily invested into the CNC machining, but later struggled to consider / allow a better/redesigned trans housing? Wouldn't that have dovetailed with CNC opportunities?

I've had (and still have one) Case-O-Matics. Like the Allis power director, it was one of the few really robust/reliable of the early tranny variations (unlike Ford's selct-o-speed, IH's TA, etc.). They were excellent for pulling - put it in torque converter mode and just increase the throttle until in started to pull. Even back in the day before pulls got crazy they were banned from many tractor pulls because they'd wipe the board.

I think the main reason the Case-O-Matic didn't catch on big their strong-suits becoming obsolete: Their benefit was for heavy pulling/lugging - they'd maintain a constant pull by varying the ground speed and RPM to suit when in torque converter mode. They excelled at this, but they came right at the time when keeping constant RPM and steady ground speed was becoming more important than lugging capacity. You wouldn't want to run any PTO equipment in torque-converter mode, because your RPM and ground speed would be all over the place. Not that this was a problem - you'd just put the converter in locked mode and it would operate like a normal tractor, but it meant the torque converter aspect was just an extra complication that wasn't really doing anything for you.