I have just swapped out my c-6 for an NP 435 in the past few weeks i finished up and was ready to start it up and go. It started up and when i put the transmission in gear and started letting out the clutch it wouldnt move and started to die, i then realized my transfer case was in neutral thinking this was the problem i put it into 2 high and it did the same thing as soon as i let the clutch out with the truck in gear it dies...out of gear it runs. I then thought back that when i was attatching the driveshaft between the transfer case and transmission the yoke on the transmission wouldnt move while it was in neutral. I havent been able to work on it since and i have been racking my head trying to figure out what i got wrong...i was hoping to get it narrowed down before i went back to work on it on tuesday. By the way the truck is a 77 highboy with a 400 any help is greatly appreciated.

 

You have a problem in your transmission for sure. Did the input turn freely in all gears, and move the output shaft? One thing I had happen to me was the bolts I used on the flywheel had too tall of a profile. The clutch would not disengage, the bolts were grabbing on the springs of the clutch. So what you are saying is you push in the clutch while the truck is running, put the truck into gear, let the clutch out, then the truck dies? What happens if you try to start the truck while it is in gear. If you lift the rear end, spin the driveshaft with the tcase in gear, trans in N, will the shaft between the trans and tcase spin? I would venture a guess that you need to drop your transmission again, to see WTF is going on inside there. (or at least pop the PTO cover, and top.

Something that just crossed my mind. I bet a dollar the transmission is in two gears at once. You need to take the shifter out again. Look down in there, you will see three "thingies" (detents in the shift rails). You need to make sure that they all line up together. If one is up, second one in the middle, third is up, your transmission is in two gears at once. (think transbrake.) Use a big honkin screwdriver to move them back and forth to get a feel where the middle is, get them all to the middle, and see if it is still locked up.

 

Im sure your right about being in 2 gears at once that was my thought but i really didnt know what i would do about it anyway and i had the top cover off while i was cleaning the transmission so im sure i screwed something up...plus i failed to mention that it will not go into 4th gear just sitting there whether running or not. Im going to look at it tonight, i guess im not quite sure you mean by middle with the three "thingies" if i remember correctly the one longer one is always towards the back of the transmission. The other 2 could be put to the middle no problem but just making sure thats what you mean or am i way off base.

 

The shift forks have plastic inserts on them...did you notice if they were still there when you looked inside the trans? No inserts = the truck won't go anywhere.

When these little buggers break, the pieces float around inside the transmission...sometimes that can jam up the works.

2-D2TZ-7C430-B .. Insert = Ford list price $2.05 each

2-C2TZ-7C430-B .. Insert = Ford list price: $2.69 each

1-D5TZ-7153-A .. Gasket Set = Ford list price: $22.51

The pressure plate bolts are special on 400's, different than 351M's, and other engines used.

6-357235-S .. Pressure Plate Bolt ~ 5/16" -18 X 7/8"

 

i dont remember any inserts on the shift forks or floating around for that matter i guess at that price i can go buy them and replace them regardless. The pressure plate seemed to bolt up fine and the clutch seems to be working just cant get the truck to move.

 

I was just wondering where i would find these insersts for my Transmission when i took the cover off there was one that was in bad shape the rest looked good but i have been unable to locate a place to buy them do you know anyone that carries them?

 

435's can be a pain to get all 3 forks lined up. pull the top off again. it def sounds like its in 2 gears at once.

 

Try here see if this what you need

http://broncograveyard.com/bronco/i-...erhaul_kit.htm