Manual four wheel drive not engaging

Hi,

So the transfer case shifts to low, but the front differential isn't engaged, correct? First, there are a few different differentials that were used. Are there any vacuum hoses running to the front axle?

As far as the transfer case, when in the 4 x 4 mode of operation, torque is transferred from the main input shaft through a high load capacity chain-link belt to the transfer case front output shaft. The front output drive shaft then transfers this torque to the front differential. So, either there is an issue with the linkage or an internal failure.

Is there any noise when you engage the 4wd or anything that may help me diagnose? If the linkage is good and the front axle isn't getting power, then we may need to take the transfer case apart to inspect the chain-link belt. So, let's make sure it isn't an adjustment issue. You may want to disconnect the linkage at the transfer case and try shifting manually to see if you can get it to work. Just make sure the truck is secure before getting under it.

I attached a pic and circled the chain I'm referring to.

Let me know.

Joe

The problem sounds internal in the transfer case. When you shift, it should engage. If it is a manual axle (lock out hub) the locking is done at the hub manually. If there is no power to the front differential, it has to be linkage or the transfer case. Whether the hubs are engaged or not, the driveshaft should turn.

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There are two different possible shift set ups. I'm going to provide adjustment directions for both. Check them. The attached pics correlate with the directions.

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2000 Ford Truck F 250 4WD Super Duty V10-6.8L VIN S
Gearshift Linkage Adjustment-Cast Magnesium Shifter
Vehicle Transmission and Drivetrain Transfer Case Adjustments Gearshift Linkage Adjustment-Cast Magnesium Shifter
GEAR SHIFT LINKAGE ADJUSTMENT-CAST MAGNESIUM SHIFTER
1. Shift the transfer case into 4x4 High.
2. Raise and support the vehicle.
3. Inspect the transfer case shifter assembly (and repair or install new components as necessary) for:
visible signs of damage.
Corroded or damaged pivot bushings.
4. Inspect the shift control rod (and repair or install a new control rod as necessary) for:
visible damage.
Bent or damaged rod.
Correct control for engine application.

Pic 1

5. Loosen the shifter thru-bolt.

Pic 2

6. Adjust the gear shifter.
1. Move the shifter base to contact the ramp.
2. While maintaining this alignment, tighten the shifter bolt.
7. Lower the vehicle.
8. Test the system for normal operation.

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2000 Ford Truck F 250 4WD Super Duty V10-6.8L VIN S
Gearshift Linkage Adjustment-Stamped-Steel Shifter
Vehicle Transmission and Drivetrain Transfer Case Adjustments Gearshift Linkage Adjustment-Stamped-Steel Shifter
GEAR SHIFT LINKAGE ADJUSTMENT-STAMPED-STEEL SHIFTER
1. Raise and support the vehicle.
2. Inspect the transfer case shifter assembly (and repair or install new components as necessary) for:
visible signs of damage.
Corroded or damaged pivot bushings
3. Inspect the shift control rod (and repair or install new components as necessary) for:
Visible damage.
Bent or damage rod.
Correct control rod for engine application.

Pic 3

4. Shift the transfer case to the 4x4 HIGH position.

Pic 4

5. Loosen the two transfer case shifter-to-transmission adapter mounting bolts.
6. Verify the transfer case shifter is still in the 4x4 HIGH detent position and hold the shifter handle against the 4x4 HIGH stop while tightening the two transfer case shifter-to-transmission adapter mounting bolts.
7. Lower the vehicle.
8. Test the system for normal operation.

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Let me know. I have a feeling something is bent or out of adjustment.

Joe

I have to be honest, if the lever is moving and nothing is happening, I suspect it is internal. Did this happen all at once and how was it first noticed? For example, were you using the 4wd and it stopped working, or is this the first time this year it was needed and failed to work?

Joe

Okay, do you think it was sold to you this way?

Joe

Low range will still work even if the front differential isn't engaged. When selected, you are simply changing the gear ratio.

Let me know how I can help.

Joe