Repairing a 4 wheel drive that's not engaging

ford
f150

#1

I have a 4 wheel drive truck, with the 4 wheel drive not engaging.



Is it better to have a auto repair garage diagonis the issue or take it to a transmission shop?


#2

I would try a good independent mechanic in this case. There are many small problems that can keep the 4 wheel drive system from engaging. My 2001 S-10 had this problem from time to time and it turned out to be an inexpensive switch on the dash.


#3

When you engage 4wd on this truck is it a simple push button or do you have levers on the floor of the truck? If it is push button…try this. Turn your ignition key all the way on without starting the truck and push your 4wd button…listen for your xfer case to shift into 4wd…you should have no trouble hearing it. Try pushing it multiple times for it to go from 4wd and back again… If it is engaging you will hear it whirring and maybe a little click or clunk…lol…if you hear nothing then the issue is with the shift motor on your xfer case, the relay that controls it or the button/switch itself. It is quite possibly a fused item so look for a 4wd fuse or relay…if you have a relay…switch it with another relay that is in your fuse box as many are identical

If you DO hear it then I need to know if on a normal basis when you engage 4wd do you need to exit the truck and lock your front hubs? OR are they Auto lock hubs? If they are auto hubs then they commonly fail but when they do you will still get the 4wd light to light on your dash and just the front wheels will not be locked up…I am guessing that your light on the dash isnt lighting…which is why you wrote this…need to know this info

How do you know its not engaging? by the light on the dash?

Complete failures of those xfer case shift motors is not entirely uncommon, but they are pretty reliable…when they fail it is usually due to the xfer case motors switch contacts…they tell the motor what position the shaft and motor actually are location wise…on the xfer case in relation to 2wd and 4wd.

DO the test I outlined and let us know what you get…


#4

Hi Honda Blackbird

  1. Engaging is via a lever on the Floor.
  2. The 4wd light is lighting up on the dash.
  3. Since we live in snow country, I can tell it’s not engaging, based on how the truck acts on ice and snow.

#5

And 4. Auto lock hub’s.


#6

OK GOOD…I like it simple. This is pointing to your front hubs then…are they supposedly “AUTO-Locking Hubs” If so your issue resides there. THey can be taken off of the front wheels and cleaned and re-greased. A lot of times the grease gets old and thick…and in the cold it is even thicker…like glue. NOT GOOD. The grease needs to be very thin…in fact I fix many auto hubs after degreasing them by pouring ATF fluid in them and let them sit overnight…then I apply a nice thin clean grease…this allows them to rotate and properly engage the front wheels on 4wd.

Look this up on the net…MANY people have the same issue and someone will have posted how to get the auto hubs working again…it will be very similar to what I suggested

Once they are cleaned and degreased and new grease applied they will have a fair shot at actually locking up again. Your issue is in the front hubs.

Many of us with Fords switch over to Manual locking hubs…they rarely if EVER Fail…the only issue is that once you pull your 4wd lever you need to exit the truck and actually switch the hubs into lock position…Dead rock solid reliable…We hate Auto Hubs in the FOrd world…why? You already know…


#7

Hello Honda Blackbird.
My Tahoe has a button shifter for 4wd. I tried the first method and it will try to engage but only in 4hi not auto 4 or 4lo. It doesn’t have front lock hubs. It has the electric system with the switch. Only my back tires spin when there’s ice the front two won’t engage.


#8

It is best to start your own thread with a good description of your problem and you will get better answers. Hondablackbird has not been here for some time.