Rear beam arm

Rear beam arm – the problem and construction of the unit

The rear beam arm of Peugeot, Citroen, Samand may sometimes be in want of repair. Arm torsion bar suspension of Peugeot, Citroen are worn because of broken needle bearing.

The unit looks the following way: the axle (pin, shaft) is pressed into the beam. The needle bearings are pressed into the arm in the certain matching sites. The needle bearings together with the arm are placed onto the shaft of the rear beam. So the shaft serves as a race for the needle bearings, which are pressed in the certain place of the arm. There two bearings in each arm. With the help of the needle bearings the arm "swings" on the rear beam axle. The tension of the arm is supported with the help of torsions and stabilizer.

If a car had been operated with destroyed needle bearing for a long time, its rollers may spill out, it's outer race – turn over or destroy. In this case the racer will destroy its matching site in the rear beam arm.

In the most cases problems in the rear beam are caused with moisture getting there — lever, pin, rear beam. The surface of the pin (shaft, axle) has nigh hardness of 58 HRC — 63 HRC, but it doesn`t save from corrosion.

If you look at the needle rollers of the bearing, you`ll be surprised at their small size and you`ll understand, that you pay for the compactness and comfort of the torsion suspension. The needle bearing of the rear beam of Citroen, Peugeot, Samand has no inner race. Very thin rollers move on the surface of pin. The rust, appearing on the shaft surface, moves through the bearing rollers and serving as abrasive hastens the attrition and destruction of rollers and pin surface.

needle bearing

Overhaul manual for the rear beam of Peugeot, Citroen, Samand. Repair of the rear beam arms of Peugeot, Citroen, Samand is a complicated process. It requires some experience. It is very likely not to notice the wear of the matching site for the needle bearing. Sometimes the "specialists" find the rear beam wear negligible and don't think that the rear beam restoration is needed, saying that the roughness of the surface is covered with the outer race of the needle bearing. But the problem lies not only in the roughness of surface. It is ellipse or nonroundness of the mounting surface which is hardly noticeable and not easy to discover even with special tools.

Restoration or renewal of the rear beam arms of Peugeot, Citroen, Samand is made in workshops, places with metal–working machinery. For that lathe and boring machine are needed.