trans questions

[Tylerz281500]

if this is the wrong section or improper for the site in general please remove.

my 4l60e is living by pure miracle right now, it functions properly but is in no way healthy. question is i can pick up an 80e and tcase fairly cheap(its a crapshoot if its any good i now) but its something ive always looked into swapping to in general so i have some qestions ive yet to find answers to.

1) Im terrible with wiring, are their differences between years of 4l80E's like their are certain years of 4l60es? this would be going in a 94 so im not to sure what wiring in eed to change or add, i know once wirings done i can add the 4l80e specs into my tune instead of the 60e trans specs.

2) Im told that theres a minimal 1mpg loss from going to the 80e? any truth behind that? my truck is tuned well but shes gotten really tired over the last year, my goal was to use the motor i just rebuilt and swap it in, find another 60e and use the spare case i have since that was redone and low mileage in general as well, but finding a 93-94 60e in any decent shape is hard im finding.

3) Overall dimension difference, how much longer will the 80e setup be? Its a 93 2 door yukon, 6" lift, not at all cranked 3" block in rear(for now) i built a proper driveshaft for it awhile back when i worked at CCI Driveline so too much longer and ill be bottoming out at ride height. That can be solved by a bit of crank and a 4" block which once again would be temporary, until i feel like dropping tank for drop hangers and my d44 up front

4) 80es share the same spline output as a NV35/4500 correct? so one of those should mate up if i cant find an manual shift case behind the 80e already?

[fastacton]

On the wiring issue, the 80E wiring is different than the 60E, but remains the same through the years. I believe you can re-pin at the ECM to get the trans connector wiring correct, but I may be wrong. You'll also have to add a second VSS connector & wiring for the Input speed sensor (ISS), it uses the same connector as the coolant temp sensor. Also, stay away from the '93 and earlier 80E used with the '7060 ECM. It has a different force motor in it that's not compatible with the '94 ECM.

[Tylerz281500]

ive seen the adding of a vss sensor and not sure how that goes yet, seems like the majority of wiring is literally swapping the blue and white wire, seems simple enough. ive seen adapters online also that the secondary vss is tapped into a few of the wires as well. so anything 94+ should work correctly in my truck 80e wise?

i know the transfer cases are all the same length but the trans itself is a touch longer. are slip yolks the same then? also talking to someone they said i dont need to tun emy computer for the 80e i can keep the 60e tune and itll work fine? changing tunes isnt a big deal just wondering what truth there was to that.

[Tylerz281500]

another question do i use my stock plug mines a 93 or do i literally have to use the 80e plug

[fastacton]

You should be able to use your stock plug, just make sure the proper wires have been swapped.

[Tylerz281500]

yea add a vss sensor and swap the brown and white wire and use an 80e tune

[Fast355]

yea add a vss sensor and swap the brown and white wire and use an 80e tune

On my 97 Express the factory 13-pin 4L60E harness was not long enough to reach the 4L80Es connector. I cut the factory 4L60E connector off the harness and extended the harness with a 4L80E connector cut off approximately 2" from the end. I was able to wire the input speed sensor to the two un-used 4L60E wires and repin on the PCM end accordingly.

[Tylerz281500]

i guess thatd work too, from what i recall the 93-94 4l60e has 12 pins i believe and the 80e has 11. ill have one unused wire, and were does the vss tap into? thats rather unclear still.