Transmission Swap 5.0 to 4.0

[Navin Johnson]

Can I replace my 98 4.0 transmission with one from a V-8? I have the 5R55E in it. If so, is the wiring harness the same as well?

 

[XLT99]

Most likely not. The 5.0 trans is a 4R70W, while the 4.0 trans is a 5R55E, and id imagine they have different bellhousing bolt patterns. Plus even if they did bolt up you then might run into issues with the ecm to trans compatibility. One might be longer than the other, which means modifying the driveshafts. The 4.0 and 5.0 use different transfer cases also
Any reason your planning on swapping the trans?

 

[Navin Johnson]

Transmission Swap

Yes, I need a 1998 with an output shaft speed sensor only and not an input shaft speed sensor as well. I replaced the transmisison with a 99 from the junk yard and because of the two sensors it confuses the computer. Well if I can't make this swap can I just not use the front sensor and go back to the 1998 wiring harness on the 1999 transmission that I now have in it?

 

[rabbit91]

Best bet is to stick with the transmission made for the 4.0. 99% sure you can use the 4r70w