What's wrong with my 4 Wheel Drive?

[Jspafford]

It is the same principle as an open differential. If one is stopped the other is spinning twice as fast. So if the axle on one side is locked to the hub the opposite side will be spinning quite a bit faster because of how an open differential works.

Ford had a problem with their Expeditions and the "Auto4WD" system making a big ass CLUNK when it shifted because the front driveline was spinning at two different speeds.

Maybe I am not 100% right, but you can bet I wouldn't want to be running my 4wd around with one hub locked and shift into 4wd.

 

[MAKG]

Guys, I might believe that in 2WD, but the VEHICLE IS MOVING because the rear end is moving it. This will turn both front wheels at the same rate when moving forward without turning. The gearset is forced to move at EXACTLY the same rate as the rear gearset because the transfer case locks them together. So, how do you get "twice as fast" out of this? The only solution that respects both of these is for the free axleshaft to spin at the same rate as the locked axleshaft -- i.e., no differential motion. It's not a stuck front wheel drive vehicle. NO tires are stopped.

 

[Jspafford]

No, I am saying if he were to have it in 2WD the one axleshaft is locked to the wheel spinning at roadspeed. The other is just free wheeling at whatever speed it wants to, wither it be the roadspeed or not moving at all.

Hit the 4WD switch and it could be nasty.

 

[Bent Bolt]

+1

 

[nobbyv]

I have this same issue but on a '95 Ranger (meaning no vacuum hub locks according to the article from the Tech Library): indicator lights in cluster illuminate fine, gearing drops in the rear in 4WD-LO, but no front engagement in LO or HI. Any ideas for me? I've been searching the forums for hours now, and nothing sounds exactly like my problem. The shift motor failure seems to have different indications( no indicator lights, or blinking lights). Mine has steady, solid lighting but no 4WD (I jacked up both ends and verified).

 

[TireIron]

do you have manual or automatic hubs on the front?

 

[nobbyv]

Auto hubs.

 

[Jspafford]

If you have positive engagement of 4-LO and the dash lights work, chances are strong that your auto hubs are shot. You can either replace them, or put on a set of manual hubs.

Most people go the manual route.

 

[roadhawg]

I got my front hubs working fine now. I did the mod and removed the metal clips from inside the hub and it works. Well, I'm excited anyway. Thanks for the input.

 

[jck_p]

PVH Modification to Manual

One question on the article about "Getting Around the Vacuum Hubs" on the '98-'00 Rangers: The mod makes the hubs permanently locked - Great! But, can you still use the dash electronic switch to 4High "on the fly"? I know NOT for 4Lo but what about 4Hi? Are there synchro's or something that allow the locked hubs and spinning front axles to engage with the T-case on the fly?

 

[ashleyroachclip]

I have a 94 Ranger STX supercab .....
I did the manual hub swap as soon as I got the truck ...4 years ago .
I run with the hubs locked most of the time .
I am always driving into some situation , where I need to be in 4 wheel .
It becomes a pain , so I am lazy .
In 2 hi , I can push the button , and it shifts to 4 hi ..
I stop /clutch to the floor , and then it will shift into 4 low, but not until I put it into 4 hi.
Just like stock .