Need help ! I have 77F-150, 351M, C-6 4x4. Was pulling up mountain in 4 low and everything doing fine. Got to flat road and switched to 4 high and when I put it in D, have no gears at all. Nothing. No 2w, no 4w high or low. It grinds when put into park. All linkages are ok and move normal.
It acts as if the TC is in nutral, but it does not have that option. It is an NP203 married with part time conversion, manual locking hubs only 4 low, 4 high and 2wd. Fluid is ok and when this happened, there was no noise, no clunk or pop.
Left it on the mountain and need to go back and fix it 'cause it is 120 miles from home.One mechanic says symptoms of TC since shaft in trans is turning(grinding going into park). Another says trans since shifting 4w lever to 2w position lets front shaft move and in 4wd locks the shaft in front diff.
I need some probable causes before I go back because trans is too heavy to drop on dirt ground. Could get TC out but would rather leave it on if it is trans because if trans, I will have to tow it 120 miles over mountains.
I really need some input on this because the cost is going to be outragious. Hoping it is TC as that would cheaper than a c6 and tow bill.

Sorry I'm so windy on this. I really appreciate any thoughts on this. It could not have happened at a worse time. Thanks.Rod

 

I agree that the problem is in the TC, the grinding noise tells you the park gear is turning and that's on the output shaft of the trans. I would crawl under the truck and make sure the linkage for the TC is moving, and or move it by hand.

 

jk080, thanks for reply. The linkages are moving as should. I think I will drop the TC where she sits and have it looked at if there is nothing obvious.I can handle it as it is about 80 lbs but trans is a no on dirt. Thanks, your reply coincides with another trans mechanic and better news could not come about! You can't imagine the situation I am in: 2 1/2 miles from hard service on a mountain with roads that look like dry rocky creek beds. No chanch of a tow truck getting to my truck where it sits, can't get a vehicle past mine to tow it forward without making a road, cutting trees out of the way. Can't push it over rocks & brush or turn it around by hand: in a terrible spot! When I go back I'll have to find a spot to turn around and back up to my truck because can't back out once I'm to my truck. Might have to pull it backwards down mountain a ways before pulling TC. When I get out of this, I'll pick my off road spots more carefully! Thanks. I sure hope it is the TC. Rod

 

Before you pull it out you might want to remove the PTO cover if it has one and see if you can access any of the shift forks and or shift collars. Have someone in the truck move the shifter and see if you can tell what happened. You might be able select a range with a big screw driver by moving the shift collar into place if the fork is broken. It has been a long time since I was into one but looking on the internet I found some good pictures and I think it might be possible. You just might drive it out if your lucky. Hope it works out for ya.

Here is a picture that may help, with the screwdriver try to move the shift collar that is on the top shaft.

 

Thanks. If it works out that I drive it out, I'll be the luckiest red neck in town! I'm so dumb on trans. & TC's! I've done about everything on vehicles execpt auto trans, & TC's.I'm going back there next weekend to try & get it out. Thanks for the tip-I would not have thought to do anything but pull it.
BTW, when I pull the PTO, will I lose oil from the TC? Rod.

 

Yes, take oil with you!

-Enjoy
fh : )_~

 

Festus, thanks. I'm so dumb on trans. & TC's . But, I do know the NP203 takes 30wt. oil! I planned to take some with me anyway, but one reason I asked the question was to know whether I was going to get a face full of oil! Thanks, I'll be ready to catch it with a can or open mouth!! LOL. Thanks, Rod

 

I learned at about 6 years old to keep your mouth shut when working with oil under a vehicle... I got a face full of ATF!

Pull the drain plug and drain it into a bucket or something so you don't spill oil all over the ground that you will be crawling around on!

-Enjoy
fh : )_~

 

JKO80, Thanks to your input, I solved the problem and drove my truck out of the woods! When the problem happened, I had shifted from 4wlow to 4whi.I pulled the shifter all the way back hard, and then had no gears! Looked under truck & had son move shifter and all linkages moved normal. What I didn't know was that linkages were packed with red mud and caused lock nut to move just enough to not let the tc linkage travel far enough to lock into gear. I took linkages loose, worked them & dug out mud & got it into 2wdrive! Drove it out. This weekend I will hose off the underside, lube all & reconnect linkages & adjust them. Lesson learned: Pay attention when experience speaks! Thanks again as this saved me more headace and expense than I can describe.
Festus, thanks, I took oil with me along with a pan but didn't need either. I am one lucky redneck who has learned to be more cautious than cocky when choosing 4wheel paths.
Thanks, Rod.

 

Awesome!

-Enjoy
fh : )_~

 

Nice job!!