It is so embarassing I contemplated not coming forth, but having this unique ability to laugh at my own idiocy sometimes and to help others with this mod, I have to tell on myself....
When I took it back apart and after I had verified that there were no cracks or warpage of the trans, I slowly and carefully put it back together and found, with help from these pages from the TSRM, the spring problem.
With my handy-dandy dial vernier caliper I found that I had somehow gotten the springs mixed up (a hazard of doing the job with the tranny in the car I guess) maybe a C-2 or B-2 in the C-0 position. I don't know if it was finding reverse or first, I'm not sure which one, when shifting to OD at about 50-60 mph. All I know is it left two nice black skid marks on the pavement before I had time to push the button again. Of course when I saw that spring was about 200 thousanths too short I knew immediately.
This time I went back together with about 5/8" shim which is violent to say the least but not at all uncomfortable except at slow speeds. I also think that I would benefit from a single driveshaft, it seems to be rough on the carrier.
I know that I initially did some damage to this tranny after the rebuild and I'm not happy with the place that rebuilt it. I know I roasted it at least once, I was running 1.1 bar or so, and I can smell the burtness in the trans, I've since turned it down. Had I known of this mod that may not have happened although I do think it's too much for the 340 to handle. We'll see how long it lasts with this mod, so far it is a huge differance. If it doesn't survive I will do the build myself once before giving up and going GM.
Many thanks to Jared and company for this mod I think my last tranny may have survived had I known this. I do think just about anybody (except for me it appears :lol: ) could do this mod with the tranny in the car with the help of that green dissolving grease or two people holding the pieces in the right spot, although certainly the right answer is to take the tranny out. Good luck folks and here are the TSRM pages.
http://www.cygnusx1.net/supra/library/TSRM/at/AT_136.html
http://www.cygnusx1.net/supra/library/TSRM/at/AT_137.html
If I think of anything else I'll edit and I'll keep you updated.
Mark