Hello everyone, I'm new here but this seems to be a solid place to pose a real question.  I have a 1970ish AC653 dozer.  I'll give you a little back story.  I bought this crawler from a construction company I used to work for about 10 years ago for 3K I thought it was a steal.  I'm no professional mechanic but I have a few tricks up my sleeves.  I ran it at home/farm for a few weeks after initially getting it and the left steering was just always engaged.  Right before I bought it, it was used to grade a lot and both clutches functioned properly it even loaded correctly.  It was like a curse as soon as I unloaded it and put it to work the left side would not disengage.   I ran it any ways and did a lot of work mainly aiming it with the functioning right side and sending it in a straight line.  I ran it for about 10 hours before I broke the left final drive-drive shaft.  Got a neighbor to tow it closer to my garage and found a shaft online, split the track and replaced the shaft.  Put it back together and ran it again.  Another 10 hours or so in and the thing starting puking diesel contaminated oil everywhere.  The crankcase was overfilled to the brim with diesel in the oil.  Did some research figured it was the umbrella seal in the injector pump so I had the pump rebuilt and reinstalled the seal.  *fixed*.  Well its been a while and I would really like to put the machine back to work again, but I don't want to break another final drive shaft.  So I'm digging into the stuck left steering clutch.  I have the cover off and I'm probing and prying and trying to understand why it will not disengage. 

-Both brakes work, both will hold the machine from rolling on a hill in neutral, and the left (stuck) attempts to bog the crawler.

-The hydraulic assist steering "works" the cylinder/rod engages and extends and can be manually pushed back. 

-The release fork and throw out bearing does not seem to have enough travel to reach the fingers on the clutch pack

-The release fork and hydraulic assist pedal do not return to any neutral/released position without me prying on something manually. (all the springs are in place)

-The throw out bearing does spin freely and doesn't appear damaged.

I attempted to "adjust the stilt pin linkage" with the large bolt on the outside of the crawler behind the sprocket, but it only seems to slightly move the rod that the stilt pin linkage rotates on and doesn't seem like the correct thing to do.  

It seems like the throw on the the release fork is not enough to push the throw out bearing into the fingers.  I feel like I'm missing something really simple.  Should I seal the clutch case and try a solvent and assume the clutch pack is frozen closed, before I go full on a pull the pack?  Or am I missing something?  

I also brought the adjustment screw on all three fingers nearly all the way out to see if the pressure plate would move closer to the throw out bearing and it changed nothing.  I did this with the clutch inside the machine trying to see if it's an adjustment issue or stuck.  I can take pictures and videos.  I just really need a second opinion before I take even more things apart.  

Thank you for pondering my conundrum!

-Nick