4WD Diagnosis?

[Ron Vroom]

I've got a 92' F-150 4x4 Xlt auto hubs. Sometimes when I am in 4 WD, it seems to slip out of gear, engine is running but seems like it is in neutral, with no wheels driving. When and if that happens, when I push the button to take it out of 4wd, there is one helluva bang, but it comes out of 4wd and I am back in rear wheel drive. If I take it in and out of 4wd, before the slipping starts, it is OK. But once it has slipped, the big bang is inevitable. Needless to say, I avoid putting it into 4wd as much as I can.

[Valv]

The big Bang is the transfer case getting in and out of 4wd, not good for it.

Have you checked/replaced the fluid ? If your wheels are not straight and truck is a curve it will not "grab" right away.

I don't like pushbutton 4wd, all my trucks have the solid lever on the floor so I know what is what going on, and if it doesn't engage righr away, you might have to abckup a little then forward again.

I was hauling hay last night with 20,000lbs loads, I had to backup a couple of times to get out of 4wd.

Don't let it bang no more.....

[BobT]

I have a 2001 F-150 with the pushbutton 4wd. I too would rather have the lever. I emailed Ford shortly after getting my truck because when you select 4wd the system engages and turns on the indicator light, however the front drive shaft may not necessarily be engaged yet! I told them they should not illuminate the indicator until the truck is in fact fully engaged. Makes a heck of bang if you apply pressure about the time it does engage. The computer watches the front and rear drive shafts to be sure they are turning at the same speed before it attempts to engage the front, so I was told by my dealer.

I've never had trouble with the transmission going in and out of gear though.

Bob

[Jim Hudson]

Do not know if that year has the vacuum locking hubs. If so, check to see if you have a leak. Could be the culprit.

Also, I would change out to manual lock outs. Lot less problems for ya.

[PierBridge]

Deleted.

[Powerstroke]

The auto hubs on your F150 are vacuum acuated and you could have a leak. If you don't get a good answer here check out fordtruckworld dot youknowwhat. They are a great resource. Its a site very similar to this as far as content and quality members. Me and another guy started the MN chapter 5 yrs ago.

Anyway, theres lot of technical info there more specific to your vehicle.

[SoManyFish-SoLittleTime]

Is this happening when you are in 4WD low or 4WD high???

[Ron Vroom]

4wd Hi