Can someone help me with these questions I have?

[MrOverCast]

There are input and output speed sensors for all 4l80e. Eventually on 4x4 applications gm started using the sensor on transfer case for output. On a 91 4x4 truck, there are three sensors: trans input, trans output, tcase output. The shifter shaft location on a 4l80e also does not line up exactly in the same spot as 700r4. Not sure if will be an issue or not, as the shift linkage is frame mounted on squares. I don't remember from my 91 factory 4l80e square if linkage was slightly different or not.

So is there a way to get the shift linkage to work? and what do i do about the second speed sensor. like i said i dont have a transfer case so i feel like by leaving the second sensor disconnected it will throw codes.

 

[MrOverCast]

Your 2wd transmission will have both sensors and just connect to the harness. 411 ecu has pins for it.
Was just noting the difference on a 4x4 setup.
For the shift linkage, have to see how it lines up when installed. Difference is small, just need to install the short shift shaft. If things don't work, universal shift cable setup will.

The short shift set up is the shifter coming out of the floor right? cause I would like to keep the truck stock and original and not have 2 shifters haha ahd alright I see. so what you where saying was on a 4x4 setup the second sensor is for the transfer case while on a 2x2 setup both go to the transmission?

 

[yevgenievich]

The short shift set up is the shifter coming out of the floor right? cause I would like to keep the truck stock and original and not have 2 shifters haha ahd alright I see. so what you where saying was on a 4x4 setup the second sensor is for the transfer case while on a 2x2 setup both go to the transmission?

There are different length shifter rods that are on a side of the transmission. Short one should work with the factory bracket and linkage from 80's truck to work. Because of slight differences, it might not. If it does not work, factory parts from 91 3/4 crew cab or suburban will. Or mating universal cable to existing steering column mounted shifter.

 

[MrOverCast]

There are different length shifter rods that are on a side of the transmission. Short one should work with the factory bracket and linkage from 80's truck to work. Because of slight differences, it might not. If it does not work, factory parts from 91 3/4 crew cab or suburban will. Or mating universal cable to existing steering column mounted shifter.

that would make sense sweet thank you for the information. are all neutral safety switches on the steering column or are they in the transmission.

 

[yevgenievich]

that would make sense sweet thank you for the information. are all neutral safety switches on the steering column or are they in the transmission.

NSS switch is on the column by the firewall inside the cab on the square.

 

[stutaeng]

I created a post on that transmission I mentioned. Most stuff doesn't pertain to OP, but you may still find useful information. In post #20 you can see the difference in shift shafts and #14 shows a link to a video on how to change it. https://www.gmt400.com/threads/4l80e-early-design-comparability.49999/page-2

@yevgenievich why does OP need a 91-93 valve body to work? Is that specific to the 0411? I believe those 91-93 units are pretty rare, since they only made them in the inception. I do believe the ATSG manual does have 2 diagrams, one for the early and one for the later valvebody hydraulic circuits. Can OP just use a black box ECM instead and run a '94+ trannie?

 

[yevgenievich]

I created a post on that transmission I mentioned. Most stuff doesn't pertain to OP, but you may still find useful information. In post #20 you can see the difference in shift shafts and #14 shows a link to a video on how to change it. https://www.gmt400.com/threads/4l80e-early-design-comparability.49999/page-2

@yevgenievich why does OP need a 91-93 valve body to work? Is that specific to the 0411? I believe those 91-93 units are pretty rare, since they only made them in the inception. I do believe the ATSG manual does have 2 diagrams, one for the early and one for the later valvebody hydraulic circuits. Can OP just use a black box ECM instead and run a '94+ trannie?

91-93 valve body will not work correctly with 411 because of the cleaning cycle used on 91-93. Different force motor and slightly different circuit. Technically it will run, but not designed for it

 

[MrOverCast]

91-93 valve body will not work correctly with 411 because of the cleaning cycle used on 91-93. Different force motor and slightly different circuit. Technically it will run, but not designed for it

Thank you for all the useful information, another issue ive come a crossed is that the wiring harness thats on the engine has two o2 sensor pigtails. i assume one is for before the catalytic converter and the other is after the cat. I do not have a cat nor do i want to get one. Is there a way to get around this?

 

[yevgenievich]

Thank you for all the useful information, another issue ive come a crossed is that the wiring harness thats on the engine has two o2 sensor pigtails. i assume one is for before the catalytic converter and the other is after the cat. I do not have a cat nor do i want to get one. Is there a way to get around this?

If second set is for after the cat and not set up for two sides, then not needed. Simple to turn off in the 411 ecu

 

[MrOverCast]

If second set is for after the cat and not set up for two sides, then not needed. Simple to turn off in the 411 ecu

the issue i have with turning off the after cat o2 sensor is the engine will throw a check engine light and make the engine not run right. as what ive herd