4x4hi does not engage, but 4x4lo works fine. Any ideas? Relays are good.

 

What year , model and engine in your truck ?

 

2000 f250 super duty, 5.4 triton. Sorry. New to this. Very low tech.

 

well, i posted well over a month ago. I was told this was a very good, informative forum, with lots of knowledgable people. The only answer i got was asking what year, model, and motor i had. Because i am very low tech, and wss a first time user, i left out that info. After answering with the appropriate info, there has not been any kind of activity on this problem. I was scolded by a member for answering a thread that apparently had been a few years old. If they are that old, they should be deleted. I called the guy an *** because apparently he thinks everyone on the planet knows how to use all this techy stuff. Havent heard a word about my problem, although hundreds of threads have been addressed since. I would thank you all for your help or even an attempt to help, but that doesnt seem to apply here. I am leaving this forum tomorrow. I just would like to see some of the answers to this first. I really dont care what people have to say about this, but i need a good laugh. You all have a wonderful new year.

 

So you say 4lo works and not 4hi
.....
Now I'd be remiss if I didn't ask - you're positive the front end is engaging?

This is important because you'll absolutely notice the gear reduction of 4lo, but that in itself does not mean 4wd, it just means your "gear splitter" is splitting your gears, like the front chainrings on a bike.

So, we've established your RANGES work. Now, first, are we POSITIVE the front end is NOT pulling in 4hi but IS pulling in 4lo?

Finally, do you have a pushbutton or manual shift (lever) t-case? Front hubs are manual? And in LOCK?

 

I am sure it is engaging in 4lo. I hear the front end clunk a bit. 4hi has no noise whatsoever. Used to feel it engage and hear it when switched. Absolutely certain it does not pull in 4hi, and does pull in 4lo. Have dashbboard switch on the fly. Have one auto hub (original to truck) and one replacement hub that can be used in auto or manual. And thank you so much for the assistance, it is greatly appreciated.

 

I've asked questions of forums, gotten lots of views, but no answers. It is how it is. I would rather have no answers, than stabs in the dark from people who just want to say something.
Stick around, and be more understanding. This IS a good forum, the best on the internet for Fords. Try posting your question again, change the title to draw more attention, or post it in a different category that may get more attention from people who have a good answer. Sometimes, you have to keep fishing to get your answer. Going away mad won't get you want you need.

 

Ok, regardless I'd start with the basics. Elevate front end. In 2hi front d/s should spin free by hand (best to have front hubs unlocked). In 4hi front d/s should not be able to be spun by hand. Repeat with 4lo

With the electric shift it may be difficult to get 4lo sitting still, so you can also leave the hubs unlocked, leave all 4 on the ground and just crawl under and spin the front d/s - again, it should be free in 2hi, locked in 4hi, and you may need to shift to 4lo and roll forward a few feet to get that engaged. This test tells you nothing of hub function AND I don't know how your one Auto hub will perform here.

If that checks out,move to a front wheel. With hub on that side locked, it should click in and spin that u-joint at the knuckle (just behind the wheel). For good measure unlock it and it should release within a couple rotations of the wheel (might help to spin back and forth). Repeat on other side.

Note that for any hint of 4wd in ACTUAL driving use, BOTH hubs must lock. Just one hub locking properly will NOT make that one wheel pull because you have an open diff (watch My Cousin Vinny). If you should have a factory LSD (limited grip, er I mean slip differential), it doesn't count 'cause they sucked.

NOW, here's the thing: if your initial description is correct, you likely have either a t-case shift motor problem OR internal t-case problems. The former seems a bit unlikely because they're usually all or nothing, AND shifting to 4lo is a LOT more work for the motor than just going to 4hi (it has to shove the range fork AND front output fork around and the planetaries usually put up a fight, for 4lo).

The latter also seems unlikely but if high mileage, maybe.

Thus I'd start w the basics and K.I.S.S. before undertaking a t-case rebuild or throwing a shift motor at it

 

Thank you for your input. I'm not mad, just a bit disappointed. Not expecting miracles, but after this long, someone could at least try pointing me in the right direction. Wwr answered today with a few more questions about it. Would like to see problem solved because I'm in michigan and snow is starting to fall. I would like to thank him again for his input if he can come up with something. I would take it to dealer, but due to a surgery i had, I'm a bit low on funds.

 

Do you turn a **** in the cab or do you move a lever to engage 4 wheel drive?

You say 4L works, but 4H does not? Are you coming to this conclusion because you don't hear a clunk when you engage 4H?

 

Have had the front end off tbe ground, and all four off tbe ground. Front ds turns in all but 4lo. Hubs engaged or not. Unsure what you mean by k.i.s.s.?

 

Ok then I'd say 1 of 3 things:
1) your dash switch is faulty
2) your t-case shift motor is faulty
3) the t-case has worn hard parts internally

You can check for 1 and 2....I'd probably first pull the motor and have someone shift 2hi to 4hi and see if the motor tries to do ANYTHING. If not, I'd probe wires and see if anything changes when the dash switch is moved, ie is the motor being commanded to do anything?

Keep It Simple Stupid

 

If you have a multimeter you’re can test the switch, wiring and the motor.

 

Did ya get the good laugh you were after? Happy New Years! I hope you get it figured out soon.

Spend some time learning to use the search tool and you can usually find the answer to most questions like this. Not trying to be a wise *** here Im just sayin there is a good reason those old threads are kept around. I'm glad they aren't archived off somewhere that is paid only. It's why I joined initially and will become a paying member.

 

Does the 4x4 light on the dash come on when you shift into 4x4 high? If so then your transfer case is shifting, and the problem is in one of the hubs.