Does anyone know if a 1999 7.4 Vortec will work with a 2006 4l80e tranny and transfer

[blazindorito]

Does anyone know if a 1999 7.4 vortec engine will work with a 2006 4l80e and the transfer case it came with, with the engines wiring harness?

Or are they 2 different harnesses?

I googled it but could not find anything.

Thanks for your pre and post help.

Ernie

 

[warwgn]

what tranny do you have now? the 4l80e internal harness is the same for 93 and up, so if that is what you got now you should be able to just plug right in.

 

[warwgn]

if not here is what I am doing to put a 4l80e in mine.

http://coloradok5.com/forums/showthread.php?t=268551&page=9

 

[blazindorito]

I have a th400 and np205.

Thinking if the computer/wiring harness from the 1999 7.4 will work with a 2006 4l80e?
Not sure if the computer was the same for both.

 

[warwgn]

nope, th400 has no computer at all just a single wire for the kick down. You will need to get a stand alone computer for it.

http://cgi.ebay.com/ebaymotors/TCI-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

prolly the cheapet you will find. if you decide to do it let me know if you got questions. you can do some reall cool sh!t with this computer.

 

[blazindorito]

That computer is worth more than the tranny combo!

 

[Greg Ducato]

The 1999 computer system, if it was originally equipped with a 4L80E, will work with the 4L80E from the 2006 model. If the 1999 was 2wd then you may need to alter the harness becuase the 4x4 4L80E does not have an output spped sensor, it is located in the transfer case. It may be a good idea to invest in an aftermarket harness to use with the computer you have to bring this all together in a neat and simple bundle. Painless Performance should be able to help with this one.

 

[warwgn]

not true about the speed sensor, I just put a 4l80e in mine and it has two VSS, in the pic below the small connector in the front is the input speed sensor and the output speed sensor is just above the main harness connector. Everything I looked up and found shows both sensors in the same locations regardless of 2 wheel or 4X4, it's all befor the output shaft.

 

[Greg Ducato]

Speed sensor signal in an original GM 4x4 application is picked up at the transfer case. If you use the output speed sensor at the rear of the trans the computer will not be able to see the difference in ratio when you are in a lower range. As long as you are in two wheel high it will be smooth sailing.

 

[warwgn]

yep I will believe that, I see what your saying now. The tranny does have both but to you need the one in the T-case when in 4X4 or your shift points will be off.

Hmm good thing the TCI unit i got has a manual shift mode, just have to push the button to shift up and down, that should be fine since I only got to do it in 4 Low anyway. Got to look into a little upgrade to the T-case in the future then.

 

[Greg Ducato]

The manual mode is a nice feature to have at your fingetips! I am planning to use the 4L80E behind a TBI 454 in my 89 K5. Since I have a 241TC from a 4L80E with the speed sensor set up, I plan to use it with a factory computer and aftermarket harness to run the whole mess. My dream transfer case is a 203/205 splitter so I am going to have to rig a speed sensor into that equation when the time comes...

 

[warwgn]

looking into that now, seems there are "in-line" sensors that screw on to the T-case speedo cable out put then the cable screws into that. I just havent found one yet.

 

[warwgn]

wonder if this will work for it?

http://www.summitracing.com/parts/ATM-5291/

 

[Greg Ducato]

I need to do some research on the ppm output of the stock speed sensor on these units. I will post the info on this thread when I figure it out.

 

[blazindorito]

I spoke to Dr4x4, last night and he said that there is a shop in North Hollywood called SPEEDO and they have vss sensors that can just be placed at the rear of the tcase and the tranny that would work with the wiring harness.

The wiring might work but is the bellhousing on the pre 99 and post 99 the same?
Will it even bolt up?

 

[Greg Ducato]

I spoke to Dr4x4, last night and he said that there is a shop in North Hollywood called SPEEDO and they have vss sensors that can just be placed at the rear of the tcase and the tranny that would work with the wiring harness.

The wiring might work but is the bellhousing on the pre 99 and post 99 the same?
Will it even bolt up?

That is good info to have, thanks! The bellhousings only differ in that the post 99 will have an extra hole at the very top of the housing. This was used to bolt to the LS series engines which do not have one of the attaching bolt holes in the block on the passenger side that the earlier engines have.