Universal joints ...

A universal joint, or "U"-joint as it is commonly known, is used to transfer drive power between two shafts that do not necessarily line up. The U-joint is usually used in propellor (prop) shafts connecting the transfer box to the front and rear differentials.
The U-joint consists of a cross-shaped piece, which carries needles roller bearings at the four ends. Bearing cups are then fitted into yokes, and are attached to the input and output shafts in such a way that the drive can be taken through an angle.

As with any other component in the Suzuki SJ series, the universal joints will wear over time. The classic telltale sign of a failing U-joint is a "clunk" in the driveline when you release the clutch.





Another symptom of the U-joint failing is vibrations from the drive shaft, especially noticeable between speeds of 25 to 35 mph.

To test the U-joints for play, raise the vehicle and support it with jack stands. Put the gear lever in neutral, and engage the hand brake. Now grab the driveshaft on either side of the u-joint and twist it backwards and forwards. If there is any play in a U-joint, it is faulty and should be replaced. Rust is another sign that the the U-joint is failing.

Tools and equipment ...

Apart from the U-joints themselves, you will need the following bits and pieces to do the job:

• Hammer
• Grease gun
• Punch
• Vise
• Two Socket spanners
• Rags
• Latex gloves
• Pliers
• Screwdriver
  

Disassembly ...

The first step is to raise the SJ, and support it safely and securely on jack stands.

When removing any of the prop shafts that have faulty Universal joints, mark the two mating ends of the propshaft and diff/transfer box with a scribe, paint, or hammer and chisel. This is to make sure that the driveshaft is re-installed in the same position, thus eliminating any unwanted vibration and noise (the driveshaft will still be in it's original balanced position).

Using snap ring ("circlip") pliers, remove all the circlips holding the U-joints in place in the yokes.



Once the circlips have been removed, use a vise and socket spanners (or U-joint press), to press the faulty U-joint out of the yoke housing. Select a socket spanner with an outside diameter slightly smaller than the U-joint bearings. Select another socket with an inside diameter slightly larger than the U-joint bearings. Place the sockets at opposite bearings in the yoke so that the smaller socket becomes a bearing pusher and the larger socket becomes a bearing receiver when the vise jaws come together. Close vise jaws until both the bearings are free of the yoke, and remove the bearings from the cross or spider.


If bearings will not come all the way out, close the vise until the bearing in receiver socket protrudes from the yoke as much as possible without using excessive force. Then remove from the vise and place that portion of bearing that protrudes from the yoke between the vise jaws. Tighten the vise to hold the bearing, and drive the yoke off with a soft hammer.

To remove the opposite bearing from the yoke, replace in the vise with the pusher socket on the exposed cross journal with the receiver socket over the bearing cup. Then tighten the vise jaws to press the bearing back through the yoke into the receiving socket.

Remove the yoke from the drive shaft and again place the protruding portion of the bearing between the vise jaws. Then tighten the vise to hold the bearing while driving the yoke off the bearing with a soft hammer.

Turn the spider (or cross) ¼ turn, and use the same procedure to press the bearings out of the drive shaft.

Re-assembly ...

Insert the bearing race into the yoke, tapping it with a hammer, until it is flush with the yoke face. When doing this, insert spider into bearing race to prevent rollers in bearing race from coming out.



Insert the other bearing race on the opposite side into the yoke. Tap with a hammer until it is flush with the yoke face. Insert the bearing races on the flange yoke side in the same way.

Place a metal plate on bearing races when tapping them to avoid damaging the yoke. Once they are in place, re-fit the circlips, making sure that each circlip is fitted in the groove securely. After re-assembly, check to ensure that both the shaft and flange yoke move smoothly before fitting the driveshaft back onto the SJ.

If the replacement U-joint is fitted with a grease fitting, be sure that it faces the driveshaft.