Auto Hub Problem?

[sonik]

On my '94 with auto hubs I'll push the 4x4 button and about half the time they will lock in (well, atleast the light on the dash stays on) the others times it just clicks a few times. When trying to engage Low, most of the time it just clicks, doesn't work, and then Hi turns off. On the 4x4 module I disconnected the two left connectors, turned the key on, pushed the white button and the red light flashed four times, so I believe that indicates the problem isn't with that module. Since I can hear stuff clicking wouldn't that indicate the shift motor and any related relays are working? I know I should probably switch over to manual hubs, but I will probably be selling the truck soon, and I don't want to put too much more money into it.

 

[MrShorty]

The indicator lights on the dash don't have anything (directly) to do with the hubs. If the indicator lights aren't staying on (that's my impression from your description), then the problem is more likely a shift motor issue.

 

[sonik]

It's not that the lights aren't staying on, they just don't come on all the time. I guess there's a difference. I read a post on here saying that if you can spin a wheel by hand after jacking up the front end while 4wd is engaged, then that's bad (hubs?). Maybe I read it wrong. Well, I tried it a few ways (both wheels up, one wheel, truck running, truck ignition just ON) and the wheels spin. But, I also jacked up the rear end so all tires were off the ground and the 4wd system seemed to perform perfect. There were no problems engaging/disengaging. I "drove" in 4wd Hi and Lo and the front wheels were powered. The rear driver side wheel didn't spin much (as much as the other three) but that's because of the open diff, right? Should both front wheels spin at the same speed? They did and I guess that would explain why its bad to drive in 4wd on dry roads.

So, the 4wd system works well when all four wheels are off the ground, but after I set her down I tried it again and the same thing happened... it doesn't engage all of the time and even when it doesn't work I can hear the shift motor working.

 

[TPLYNCH]

If the lights aren't coming on, then the 4x4 shift motor is not working properly. Your description of being in 4Hi and pushing Low and the lights going off is what happens if the motor is unable to shift properly. Clean the shift motor. See Brains thread on how to do.

 

[sonik]

Just to update... I banged on the shift motor some when I had it jacked up and I've been engaging/disengaging it the last few days and it's working well. Next time I'm under there I'll take off the motor and clean it up. Thanks for the help you two.

 

[simmons1]

IF you do not use 4x4 for a while the shift motor tends to "bind up" (poor wording). To keep the shift motor from binding up, I make a point to run the X in all of the 4x4 ranges every time I change the oil. This keeps the motor it good working condition.

 

[nascar_intimid]

I engage all ranges for 5 seconds on straight dry road and then disconnect and un lock the auto hubs and that keeps everything juiced...recently I can hear a loud thud or a hard hit if my hubs are unlocked and I engage at about 20 mph or so anyone ever hear a thud kinda louder than the normal "thuclick" and it's coming from the auto hubs it just started a week ago everything still works fine except for the loud thud from the front left sometimes right wheel...it doesn't sound good

 

[MazdaGreg]

The bang is the front drive shafts coming up to speed in a big hurry. Ford states that you should be able to engage your 4x4 at highway speeds, but i know that i wouldnt suggest it. If at all possible slow down to 5 or less when engaging your hubs. These things are fragile from the factory, and anytime you have the option, either stop, or roll really slow when engaging 4x4. It will give those auto lockers a few extra years. Mine have 205,000 on them, and they still work like a champ.

 

[nascar_intimid]

point taken....will engage at a crawl from now on