Gen4 5.3 6L80E 4x4 swap problem

[theshop_steven]

The transfer case that came behind my 6l80 was electronically controlled but i cant use it, i have to use a manually shifted transfer so i dont have a TCCM on the CanBus. I need a way to either change settings in the tune or change the OS to a truck that came with a manually shifted transfer case. Anyone know how or what to do to accomplish this. Thanks

[ntilley52]

what are you trying to accomplish? I swapped a manual shift pass drop 241 behind my 6l80e. it works fine.

[theshop_steven]

I want the shift points to be correct when in low range.

[ntilley52]

it doesnt use the vss in the tcase to shift(tcase vss is just for speedo mine works without it hooked up just fine), it looks at the transmission output shaft rpm. If you want it to shift a specific MPH, instead of RPM, you could use a different position on the transmission,(a different D position) then program the shift points on that spot to match up with the low range gearing. so in operation you would move the trans shifter to one spot for high range(normal) driving and a different spot for low range. then put the tcase in low...Could something like that work?

[theshop_steven]

well knowing that it works for you without the sensor in the transfer case is a big help. i was going to flash my ecm and tcm to a VIN that i know came with a manually shifted transfer case and sent the 4WD Low signal to Pin2 on the ecm. that was the only way i could see to do it and use the 4WD Low shift table.

[LOWnEASY]

What did you have to do to make the transmission work? (Ecm wise)

[ntilley52]

TCM is built into trans. I had my harnesses and standalone tune done by mail. Only sent them the ecm never sent in the TCM. Came back and it worked. I just bought hp tuner to get my TUTD shift to work, and to adjust my tach and speedo outputs. And later on more upgrades

[CP_CUSTOMS]

hey tilley you ever get the speed and gear calc figured out cause if not get ahold of me and well figure the thing out got some spreadsheets ill shoot you also make it little less frustrating how that hood doing you

[ntilley52]

Not exactly, but close enough. The tire/gear wizard will only accept up to a 40" tire. I have 42s. That's only 2 mph difference, so that's close enough. Found out the tach issue I had was because they had 15/15 in the high low resolution, which generates a 2pulse(4cyl) signal. And the dip switches on my tach are bad so it was stuck in 4pulse(8cyl) mode. So I used values 7/7 and it is now working..

[It Will Run.Maybe]

here is where i changed my low gear transfer case ratio in the pcm to match my np208 low gear.transfer case ratio change.PNG

[ntilley52]

here is where i changed my low gear transfer case ratio in the pcm to match my np208 low gear.transfer case ratio change.PNG

its different on a 4l60e, like you are running, the 6l80e has a output shaft speed sensor built in, so it doesnt matter if your in low or high, the transmission is gonna shift at the correct RPM. the 4l60e is looking at the speed sensor in the tcase, so it needs to know when you are in low since the shaft speed will be 2+ times slower.


also Cory, hptuners tech support sent me a beta program that now excepts my 42s as a tire size, and scales properly, so its all good now

[dlc_racing]

well knowing that it works for you without the sensor in the transfer case is a big help. i was going to flash my ecm and tcm to a VIN that i know came with a manually shifted transfer case and sent the 4WD Low signal to Pin2 on the ecm. that was the only way i could see to do it and use the 4WD Low shift table.

did you get this working properly? cause im on the same trouble here its 2008 jk jeep swaped 2013 5.3 6l80 from a electronic TC silverado and it wont recognize the pin2 ground for the 4x4 LOW signal ...i cant make this cars shift right im on a T43 OS 24265260

[theshop_steven]

I am back in Iraq and I did not have time while home to completely finish the swap so I have not tried this yet.