When a single universal-, cross- or ball joint is rotated uniformly in an angled position, a non-uniform motion occurs at the output side. (See motion characteristices and torques under 2).

This fluctuation is eliminated when two single joints are connected, forming a driveline. To obtain complete synchronous motion, the following conditions must be met:
a) Equal deflection angles at both joints(ß1 = ß2)
b) The two inner forks must be in one plane
c) In- and output shaft must also lie in one plane

Exeption: If a driveline is angled three-dimensionally, in- and output shafts are not located in one plane. To obtain a uniform output motion, it is necessary in this case to offset the inner forks relative to each other so that they end up in the same plane of deflection created by their joints. Also, the three-dimensional deflection angles must also be equal. (Our Engineering Department will glady assist you in determining the correct angular offset).

Note: Incorrectly assembled universal joints do not equalize fluctuating output motion.They amplify it. This can lead to early joint bearing and spline failure. Therefore,when assembling the two driveline halves, the marker points on the spline shaftand spline sleeve must face each other.

The cross Journals and the needle bearing cups wear simultaneously. It is therefore necessary to replace both the cross and the needle bearings, if they show signs of wear.

Disassembly

1. Eliminate the tension between circlips and cups (see picture 1).
2. Remove circlips (with special pliers).
3. Press out one cup at each yoke(see picture 2).
4. Grip cup extending out of the yoke and pull them out (see picture 3).Use aluminium or plastic hammer.
5. Press out and pull off the opposite cup.
6. Remove cross (see picture 4).

The cross Journals and the needle bearing cups wear simultaneously. It is therefore necessary to replace both the cross and the needle bearings, if they show signs of wear.

Assembly

1. Insert the cross (see picture 4).
2. Press in the bearing cup on one side and secure it with a circlip (see picture 5).
3. Press in and secure the opposite cup(see picture 6).
4. Insert the cross in the second yoke.Then press in the bearing cup and secure.
5. Tensions in the universal joint can be eliminated by lightly hammering against the yokes. The joint will then move more freely.

Instructions for Exchanging the Cross Assemblies in Double Joints for Steering Axles:
The bearing cups of the centre piece are fitted with a detaching thread. These cups can therefore be removed with a puller after removing the screw plugs.
All other steps for assembling and disassembling are the same as described above.

Attention:
Before pressing in the bearing cups, make sure that all needles are in contact with the inside diameter of the cup.
After replacing any worn parts, high-speed shafts must be rebalanced in accordance with rating Q16 of the VDI recommendations 2060. If the shaft is only subject to low speeds, rebalancing is not necessary. The speed limit lies between 500 and 800 rpm depending on size and design of the shaft.
If, for any special reason, high-speed shafts cannot be rebalanced, the individual components of the yoke should be carefully marked before disassembling so that they can be realigned exactiy after-wards. In this way the Unbalance can be limited to a minimum.

Z-Configuration:

In- and output shaft are parallel to each other in one plane.

W-Configuration:

In- and output shaft intersect
in one plane.

Three-dimensional configuration:

(Combined Z and W configuration)
In- and output shaft cross each other offset in space. No common plane exists. Therefore the inner forks must be offset by the angle g (See 1.1 „Exception“).

The resultant three-dimensional deflection angle ßR derived from the vertical and horizontal angular deviation, is calculated as: