Driveshaft: Specifications Ford Explorer IV

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

The driveshaft consist of the following

1. U-joint flanges
2. U-joints
3. Nylon thrust washers, located at each base of the bearing cup, which control end play, position the needle bearings and improve grease movement
4. Lubed-for-life design and require no lubrication
5. Constant velocity (CV) joint flanges
6. CV joints
7. Slip-yoke
8. Slip-joint boots
9. Traditional welded-on balance weights

Vehicles have the following types of driveshaft

1. One-piece rear driveshaft with 2 U-joints and a front slip-yoke
2. One-piece front driveshaft with a front U-joint, a slip-yoke and a rear CV joint
3. Two-piece rear driveshaft with 3 U-joints
4. Two-piece rear driveshaft with 2 CV joints and one U-joint

Scheme 1

Note. Whenever the vehicle is raised on a hoist, inspect the U-joint slip-yoke boot for rips or holes. Install new if required.

Note. All driveshaft are balanced. If undercoating the vehicle, protect the driveshaft and U-joints to prevent application of any undercoating material.

The driveshaft transfers input from the transmission or transfer case to the front or rear drive axles. The driveshaft is composed of the U-joints or CV joints, connecting shafts and attaching yokes. The driveshaft accommodates the change in length in the driveline system by sliding on the transmission output shaft with a slip-yoke or a slip-joint which is integral to the driveshaft. The shafts vary in diameter, length, number of coupling shafts and U-joints or CV joints, depending on vehicle application. The U-joints and CV joints allow the driveshaft to rotate smoothly through the changing angles between the transmission output shaft and the driveshaft, plus the changes between the rear axle pinion angle and the driveshaft. On 2-wheel drive vehicles, power is transmitted through the transmission to the driveshaft and then to the rear axle. On all wheel drive (AWD) vehicles, power is transmitted from the transmission to the front and rear axles through the transfer case.

The engine angle is built into the engine mounts. If the driveshaft angles are out of specification, the engine mounts must be inspected for damage.

Refer to DRIVELINE SYSTEM - GENERAL INFORMATION .

1. Inspect the driveshaft(s) for signs of physical damage, missing balance weight, undercoating, incorrect seating, wear and binding U-joints. Check the index marks (paint spots) on the rear of the driveshaft and axle pinion flange. If these marks are more than 90 degrees apart, disconnect the driveshaft and re-index to align the marks as closely as possible. After any corrections are made, recheck for vibration at the road test speed. If the vibration is gone, reinstall the wheels and road test. If the vibration persists, proceed to Step 2.
2. Raise the vehicle on a hoist and remove the wheels. Rotate the driveshaft by turning the axle and measure the runout at the front, the center and the rear of the driveshaft with the indicator. If the runout exceeds specifications at the center, a new driveshaft must be installed. If the center is within limits, but the front or rear runout is not, mark the rear runout high points and proceed to Step 3. If the runout is within the limits at all points, proceed to Step 5.
3. Scribe alignment marks on the driveshaft and the axle pinion flange. Disconnect the driveshaft, rotate it 1/2 turn and reconnect it. Circular axle pinion flanges can be turned in 1/4 increments to fine tune the runout condition; half-round axle pinion flanges are limited to 2 positions. Recheck the runout. If it is still over specifications, mark the high point and proceed to Step 4. If the runout is no longer excessive, check for vibration at the road test speed. If vibration still persists, proceed to Step 5.
4. Excessive driveshaft runout may originate in the driveshaft itself or in the pinion flanges. To determine which, compare the 2 high points marked in Steps 2 and 3. If the marks are close together, within about 25 mm (1 in), a new shaft must be installed and the vehicle road tested. If the marks are on opposite sides of the driveshaft, the pinion flange is responsible for the vibration. When installing or adjusting a pinion flange, the driveshaft runout must not exceed specifications. When runout is within limits, recheck for vibration at road speed. If vibration persists, balance the driveshaft.
5. To balance the driveshaft, install 1 or 2 hose clamps on the driveshaft, near ends. Position of the hose clamp head(s) can be determined by trial-and-error.
6. Mark the rear of the driveshaft into 4 approximately equal sectors and number the marks 1 through 4. Install a hose clamp on the driveshaft with its head at position No. 1. Check for vibration at road speed. Recheck with the clamp at each of the other positions to find the position that shows minimum vibration. If 2 adjacent positions show equal improvement, position the clamp head between them.
7. If the vibration persists, add a second clamp at the same position and recheck for vibration. If no improvement is noted, rotate the clamps in opposite directions, equal distances from the best position determined in Step 8. Separate the clamp heads about 13 mm (0.50 in) and recheck for vibration at the road speed. Repeat the process with increasing separation until the best combination is found or the vibration is reduced to an acceptable level.
8. Install the wheels and road test (vibration noticeable on the hoist may not be evident during the road test). If the vibration is still not acceptable, install a new driveshaft.

Scheme 2