How to Reset Transmission Control Module?

[Mudsport96]

Tow/Haul mode causes quicker firmer shifts. The last thing you want is to be giving moderate throttle and the shift to be loose and sloppy while towing. That causes extra heat, clutch wear and will burn up the 2-4 band during 1-2 and 3-4 shifts.
It really sounds like your 1-2 spring had the piston all wedged up in the bore. Do you remember pulling the 2 spring pieces? Did they come right out or were they all tangled up together?

I'd bet that what was happening was that the piston was not in contact with the spring. Then when the shift was initiated, it would quickly move to contact the spring. Causing what felt like a shift or at least like it left 1st gear. Then the spring would slow everything for a second then collapse quickly because of the odd spring rate of a broken spring causing the harsh shift.

Then again harsh is relative. Some of my older hotrods just had cutoff deepwell sockets in place of the springs
That's the whole reason my nova has traction bars, not because of launch traction, but the 1-2 made it lose traction lol.

 

[NickTransmissions]

About a third of it broke off. It a came right out but the broken-off bit was tangled into the remaining spring. Miraculously, there wasn't any significant scoring on the cylinder wall

Excessive band clearance causes harsher/firmer/neck snapping shifts all things equal...too much WOT 1-2 with excessive band clearance = broken band...seen quite a few come in with the band snapped cleanly in half.

That's why I made it a point to ask you about band clearance.

As an aside, the size of the second gear servo also directly affects shift feel/firmness. For example, let's say your spacer plate has a .076 1-2 feed hole drilled, stock converter stall rpm and proper band clearance/servo travel has been achived...A 553 servo will feel soft-ish, an 093 servo will feel crisp, a Sonnax billet super hold servo will feel firm and a Superior Tech billet servo will real firm-to-uncomfortable.

 

[Mudsport96]

and a Superior Tech billet servo will real firm-to-uncomfortable.

Ha I "crushed" a drum with one of those.

 

[NickTransmissions]

Ha I "crushed" a drum with one of those.

Yup! I do like them but stall has to be 2800+ before Id consider using one and ill reach for the Sonnax first if its available.

 

[Mudsport96]

Yup! I do like them but stall has to be 2800+ before Id consider using one and ill reach for the Sonnax first if its available.

Part of the problem was the ecm was tuned for faster and firmer shifts and all torque management was removed before the first 60e died. Not being something i was thinking about when rebuilding, it wasn't corrected. Then after the valvebody work/ accumulator and servo work.... well let's say that the internals did not like the computer commanding full line pressure.
Heavy vehicle combined with everything trying to make the 1-2 shift happen yesterday....

Engine wanted to stay in the torque peak, Trans wanted to shift and pull the engine down... flywheel said I'm out.
All while the trans wanted to shift and speed up the output shaft, but the tires said "We have too much traction we won't slip". And the suv was wanting to wheelie, it sure freaking tried. My copilot and I thought everything was coming through the floor to get us.
Needless to say with the new shaft and flexplate 80 percent of the torque management was put back.
60es need the nanny haha

 

[rockola1971]

Part of the problem was the ecm was tuned for faster and firmer shifts and all torque management was removed before the first 60e died. Not being something i was thinking about when rebuilding, it wasn't corrected. Then after the valvebody work/ accumulator and servo work.... well let's say that the internals did not like the computer commanding full line pressure.
Heavy vehicle combined with everything trying to make the 1-2 shift happen yesterday....
View attachment 416116
Engine wanted to stay in the torque peak, Trans wanted to shift and pull the engine down... flywheel said I'm out.
All while the trans wanted to shift and speed up the output shaft, but the tires said "We have too much traction we won't slip". And the suv was wanting to wheelie, it sure freaking tried. My copilot and I thought everything was coming through the floor to get us.
Needless to say with the new shaft and flexplate 80 percent of the torque management was put back.
60es need the nanny haha

Impressive to shatter a hardened shaft like that. Reminds me of the Made in Mexico connecting rods of Briggs & Stratton.

 

[ShookieJay]

Part of the problem was the ecm was tuned for faster and firmer shifts and all torque management was removed before the first 60e died. Not being something i was thinking about when rebuilding, it wasn't corrected. Then after the valvebody work/ accumulator and servo work.... well let's say that the internals did not like the computer commanding full line pressure.
Heavy vehicle combined with everything trying to make the 1-2 shift happen yesterday....
View attachment 416116
Engine wanted to stay in the torque peak, Trans wanted to shift and pull the engine down... flywheel said I'm out.
All while the trans wanted to shift and speed up the output shaft, but the tires said "We have too much traction we won't slip". And the suv was wanting to wheelie, it sure freaking tried. My copilot and I thought everything was coming through the floor to get us.
Needless to say with the new shaft and flexplate 80 percent of the torque management was put back.
60es need the nanny haha

So what you're saying is tq mgmt is a good thing? Lol

 

[ShookieJay]

Impressive to shatter a hardened shaft like that. Reminds me of the Made in Mexico connecting rods of Briggs & Stratton.

I'm no expert in drivetranes, but in my experience with metals as a machinist, it's not shocking to me that a hardened shaft would break. I had a taper pin shear on an old (1980s) Zocca surface grinder at work. (this machine is the size of an NYC apartment and has a very large ball screw that moves the grinding head up and down) Needless to say, on a machine that old I couldn't just call up Zocca and order a replacement pin, so I had to make one. I opted to use a tool-grade carbon steel to make the pin. It's hard, but not as hard (and brittle) as hardened steel. Had I used hardened steel, it would have snapped like a toothpick. Sometimes it's good to have a little give.

 

[Mudsport96]

So what you're saying is tq mgmt is a good thing? Lol

For the 4L60E yes. In a truck/suv application when traction is good, it is a must.

 

[Mudsport96]

Impressive to shatter a hardened shaft like that. Reminds me of the Made in Mexico connecting rods of Briggs & Stratton.

Had I used hardened steel, it would have snapped like a toothpick. Sometimes it's good to have a little give.

I put these together because my reply has a commonality.
After this happened I did some research.

And what I came up with was that the problem lay within the type of shaft.
The 4x4 shafts are roughly 5.25 inches shorter than the 2wd shafts. So when they get shockloaded they have less length to disperse the load. So it went bang. I had more pictures but unlike old prints, digital pictures are susceptible to file corruption.