When replacing the universal joints, cleanliness is of the utmost importance. Any form of debris will contaminate and damage the newly installed universal joints. It is recommended to install the universal joints according to the original manufacturer’s procedures and specifications. It is also advisable to replace all the relevant universal joints on a prop shaft at the same time.
To check whether the universal joints have excessive or abnormal wear, remove the prop shaft and inspect the universal joints for lateral or axial movement. If any movement is evident, this indicates that the roller bearings are worn beyond their maximum limits and cannot operate correctly, and the universal joins need to be replaced. A worn or damaged universal joint will result in severe vibration which will be evident on pull-off and while driving the vehicle at a constant speed.
Remove the prop shaft. Mark all the relevant joints and flanges to ensure that the components are all re-installed in their original positions.
Remove all the relevant circlips from the used universal joint. If the bearings are held in using a lock ring, mount the universal joint in a vice and drive the lock rings out using a blunt punch and hammer.
Place the joint assembly in a brass or copper jawed vice. The trunnions should rest on the edges of the vice. Strike the suspended yoke with a babbit hammer and drive the yoke down until it makes contact with the cross. The upper bearing will now protrude. Turn the assembly over and repeat the process on the remaining side. Follow the above procedure to remove the remaining two cups.
Once the above universal joints have been stripped and cleaned, the new universal joints can be installed. Install the universal joint with the cups removed in the housing. Press the first cup halfway (50%) into the relevant housing. Insert the universal joint into the cup to ensure that the universal joint moves freely. Install the second cup and press the cup into position, while rotating the universal joint 180 degrees to ensure free movement.
Install the universal joint circlip and press the opposite cup home while again rotating the universal joint to ensure free movement. Install the remaining two universal joint cups using the above procedure.
Install the remaining universal joints as above, making sure that the flanges and markings made in STEP 1 all match up. This will ensure that the components are replaced in their original positions. This will ensure the extended life of the universal joints and will allow the relevant components to operate in equilibrium.
Replace the prop shaft and inspect all the relevant bolts and nuts to ensure that they are secure and tightened according to the manufacturer’s specifications.
USEFUL TIP 1:
It is advised that once the universal joints have been replaced, the prop shaft should be re-balanced and the centre carrier bearings should be inspected. This will ensure a longer life for the relevant components, and will allow them to operate in equilibrium.
USEFUL TIP 2:
While removing and re-installing the prop shaft, visually check the surrounding suspension rubbers and seals for possible deformation, fatigue or oil leaks. Replace where necessary.