Hey guys, need some quick help, I have a 99 7.3 superduty auto....I was pulling in 4x4 low....and something broke. When its in low range the truck will not move, it sounds like something is just free wheeling in the tranny. 4x4 high works, the truck runs and shift fine in 2wd....its just the four low, no movement and the free wheeling sound.....whats wrong? what broke? how much?
thanks in advance

 

I assume that you do not have shift-on-the-fly, but rather a manual shift transfer case (NV 271). From the sounds of it, it would appear that the planet/sun gear or slide gear assemblies on the low shift fork have gone south

I'd drain the transfer case and look for debris (use a magnet rod to fish debris out)...you can always refill (ATF) to drive to a shop for repairs. I'd bet money it is not a transmission problem, but rather a transfer case problem. If it was the transmission, you would have the problem irregardless of the range (high or low) and drive (2 or 4 wheel) you were in.

I've never done this job on a Ford, but have done it on a IH Scout...I remember replacing both fork assemblies while I had the unit apart. This is, IMO, a job a person can do themself if they have the time/patience. Good luck on it and let me know if you need any schematics, etc.

 

Same thing happened to me, and I was on the top of Mt. Raineer, WA. on a little vacation. Had to get towed home to the tune of $500.00.
https://www.ford-trucks.com/forums/s...d.php?t=393461

 

its me again
i have a shift on the fly 4x4 it has the **** on the dash to turn it to high or low, it doesn't have the manual lever on floorboard
maybe this will help
thanks to all that have replied so far, anymore info would be greatly appreciated

 

I see, my fault on the assumption...I still believe it is the planetary gear assembly or the range fork assembly. The symptoms are EXACTLY what I had on the Scout I mentioned.

EDIT: I've done some more reading on the ESOF transfer case...everything looks pretty much the same as the manual shift transfer case. I suppose that there could be a problem in the communication with the GEM. I found that the GEM can throw a DTC C1729 "Transfer case unable to transition between 4H and 4L". So, it could be an electronic problem that is beyond this guys knowledge...way beyond in fact !

 

Here is a link to some info I put together on ther esof transfer case...look particularly at part no's. 29 and 77...also the info on the electronics.

http://home.ripway.com/2005-4/294125...ansfercase.pdf

 

[QUOTE=nlemerise]Here is a link to some info I put together on ther esof transfer case...look particularly at part no's. 29 and 77...also the info on the electronics.

http://home.ripway.com/2005-4/294125/Ford/esoftransfercase.pdf[/QUOTE]

Try this one if I am over my download limit on the above link:

http://www.streamload.com/nlemerise/...nsfer_case.pdf