The slip yoke on a Ford F150 is a splined shaft that slides into a splined receiver on the rear of the transmission. The slip yoke allows for geometry changes while driving the F150 along rough terrain or bumpy roads. Just as the shocks absorb the impact of minor bumps and potholes, the slip yoke absorbs the bounces of the rear axle. Due to the sliding action between the inner and outer splined shaft of the slip yoke, grease is applied to reduce friction wear between these moving parts.
Park the truck on a level surface and set the emergency brake. The surface should be dry and allow easy access to the underside of the truck.
Remove the U-joint connection directly behind the transmission on the F150. A 3/8 or 1/2-inch combination wrench fits the two u-bolts retaining the U-joint into position.
Set the drive shaft on the ground and clear of the slip yoke.
Pull the slip yoke shaft out of the receiver by hand. The splined section of the shaft is between six and eight inches long. Remove the shaft from the receiver completely.
Apply a liberal amount of PTFE lubricant to the splined shaft with a rag or gloved hand.
Slide the splined shaft back into the receiver and lift the drive shaft back into place.
Install the two U-bolts into the U-joint and tighten the bolts with the combination wrench.
