'78 F100, 2WD, SWB, transplanted 351W and C6 Transmission out of an '85 E150 Club Wagon XL. Hope that explains the set up we are looking at. Both Engine and Transmission are newly rebuilt. Drove the van 20+ miles home, pulled engine and transmission to swap. - the explanation is lengthy so I will post question first, you can read the explanation for any clarifications:
1. Does the Neutral Safety Switch on the Transmission have to be hooked up in order for the transmission to engage the gears? Truck side doesn't have a hook up, so I would need to know where it hooks up.
2. Placed transmission in Neutral to push forward - felt as if the brakes were locked up?
3. Can't get the drive shaft to turn (jacked the back tires off the ramps, placed stands under to allow wheels to turn, drive shaft doesn't budge even in gear (answer may be above, just throwing out questions)
4. Transmission Kickdown Linkage - does it have to be hooked up for the transmission to function, or just for "passing gears to operate correctly"

Explanation below, sorry for the length, just trying to be as informative as possible.

The truck originally did not have a Neutral Safety Switch nor did it have a Transmission Kick Down Lever. The transplanted engine and transmission which the truck has in it now, were dropped in together, they were pulled from the van in one piece and dropped in the truck in one piece, the only thing that was removed was the starter, and I covered the starter hole up with cardboard and ducktape, to ensure no contaminants entered the case. Install went easy, have been working through some issue with vacuum lines, etc. Finally got those issues resolved moved to the next issue, transmission would not shift from inside the truck (another point, Van was a column shift, truck is a floor shift) [there is a thread on this in the Transmission Forum]...was informed I would need to drop the pan on the transmission in order to swap the linkage around to work with the floor shifter. That was on my schedule to accomplish today. Went out to pull the truck into the garage to work in the shade, and it wouldn't start, so spent all day tracking down this issue, replaced the solenoid, battery cables (needed new ones anyway), checked the distributor, wires, changed the ignition coil, checked all the wiring, ended up replacing the "electrical box" not sure on the correct name...I pulled the one out of the van along with the wiring harness. Truck started right up, went to pull it into the garage, would not engage into gear? Currently there are ramps under the rear tires, so I could work on the linkage with a little room (pushed it up on the ramps before I hooked the drive shaft back up). I can manually shift the gears on the transmission by hand, however not with the shifter in the truck (more info in the other thread C6 Linkage Issues). I was as safe as possible, had the emergency brake set, truck off, would go underneath, shift into gear, start the truck (yes it does start in gear, doesn't have neutral safety switch on the truck end; however the van transmission does have the wires, just no where to hook them into, and I have both wiring harness and neither have a location, so that is question one where is it supposed to hook to, and could this cause it not to engage into any gear?) Second thing, I placed it into neutral and took the emergency brake off and attempted to push it, felt as though the brakes were locked up? Third, while in gear, the drive shaft doesn't move (thus it isn't engaging the gears?) Fourth would the kickdown linkage need to be hooked up for the transmission to engage into gear?

Thanks for any advise and/or recommendations...I can post pics of what wiring I have in the morning. If needed.

 

The neutral safety switch is just an electrical switch - all it does is cut power to the starter solenoid if the gear selector is in gear. It doesn't affect the transmission actually engaging into gear.

The transmission kickdown linkage is a convenience, but not necessary for the transmission to function. All the kickdown linkage does is push a lever where the gear selector connects to the transmission that automatically downshifts for you when the throttle moves past a certain point, instead of you having to do it yourself. If you leave it disconnected, the transmission isn't going to know the difference.

 

Any idea why it will not engage when in gear?

 

Went out this morning to give it another try...started it up, it "jumped" a little then I couldn't get it to do it again...is it possible there is air in the transmission lines? Would that cause it to not engage into gear? If so is there anyway to bleed the lines?

 

Wooo Hooo, I was able to actually get her moving today! She is Moving!

 

what was the problem?

 

My guess is air in the lines??? Not really sure, After driving it down off the ramps, I let her idle in Neutral (still had to shut it off, set the park brake, shift it with my hand under the truck into Neutral, re-start it). and checked the fluid, it was a little low, but registered just under the "safe" mark on the stick...it registered a little full while on the ramps, so I did add some tranny fluid to it...I still have to swap the linkage around, so I will check it all when I drop the pan (hopefully this week).