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So next week I’m taking on putting a zf6 in my truck because my 4r100 just can’t take the heat anymore and all the looking around for what to do with the wiring has me lost. I have the whole parts truck kinda weird though cause the date is early 99 but didn’t have the early 99 turbo or pcm but the wiring harness that went to the transmission also went to the fuel pump and the electric transfer case witch I’m not going to be using, idk if I can use the harness out of the parts truck or if I need to mess with my old automatic harness to make it all work as it should. Any help on this will greatly be appreciated.
I really like my ZF6 truck and looked for about a year for the right truck. I then found one 600 miles away and told the guy I would be there the next day with cash in hand. In my opinion, the ZF6 is a very capable transmission that allows me to have 100% control of the gearing be that going up or down a grade.
As for your questions, I don't know if I have the answers, but I might have some advice that will allow you to find the answers you seek.
@ESwift is a very reputable FTE'r and has done at least one ZF6 swap in the past year. @SkySkiJason is another reputable FTE'r that is a bit of an expert on the 7.3L and ZF6 trucks. He helped me out with my truck many years ago and we have become family friends over the years. Maybe one of those fellas can offer some first hand advice for you.
Many of us have the Ford Service Manual on hand and access to all of the wiring diagrams, connector pinouts and schematics that may be useful to you if you are in need.
I know there were some changes in the wiring harness between the earlier and later years, but going from a 1999 to a 2000 may work for you if that is in fact the years of vehicles involved. If you have the harness, PCM and other essential parts on hand, I would use everything I could from the parts truck I could in an effort to sell and recoup some funds from the parts you removed. That is if that is in your plan.
Regarding the ZF6 swap and those that have gone before you, there are a couple of threads in the 7.3L PSD Tech Folder that you may find useful, they are linked below.
The pilot bearing is a topic of conversation at times here on the FTE. If you are looking for a better and long term solution, then check out the bearing that FTE'r @ArmyLifer has been milling for use hand shakers. Below is a link to his post and profile and a spreadsheet snip that I built in case you want to consider the other options.
Lastly, there was a YouTube creator that has some decent information on the swap. The video linked below is part 1 of a 4 part series that you may find useful.
If I read this correctly, you're going from an electronic shift transfer case (NVG273) to a manual shift transfer case (NVG271) at the same time.
in your 1999, to maintain functionality of the 4x4 and 4x4 Low indicators in the cluster, there will be some wiring changes that have to be made, basically bypassing the GEM's ground control of the lights and using some existing encoder sensor wires to now become ground-supplying wires to the lights. In longer terms, the electronic shift system uses the GEM to control both the shift motor relays AND the indicator lights in the cluster by way of monitoring a return voltage from the motor position sensor (encoder). If the shift doesn't take place (either mechanically or an incorrect voltage return from the encoder), the GEM will not supply a ground to the indicator lights in the cluster and the entire system will give you the middle finger.
With the manual shift transfer case, there is a switch mounted on top of the LH side of the case with a plunger on it. It has two sets of contacts in it that are determined by how far the plunger is pressed. These two contacts are a path to ground for the indicator lights. There is no electronic control of the lights in the cluster....either one set of contacts is pressed mechanically or both are pressed mechanically. To maintain the function of your indicator lights, two of the existing encoder sensor wires will have to be used for the purpose of getting the ground signal to the GEM connector and then those wires will have to be cut and spliced to the ones that run the indicator lights. Keep in mind too that there is a 4x4 low signal to the PCM; it's not too important for a manual transmission vehicle but if you were to be keeping an automatic the transmission would have a hard time upshifting in low range because the PCM HAS TO KNOW to divide the perceived vehicle speed by 2.71. It'll shift.....at redline.
04-01-2023, 10:37 PM
