Thrust Bearing 8104

Thrust Bearing 8104 for Lifting Mechanism of ZM-60U/90U/120U and ZMB

The thrust ball bearing 8104 (GOST 520-2002) is a compact yet critically important contact element in the kinematics of the screw lifting mechanism for modern grain loaders in the ZM and ZMB series. It is also found in modifications of classic ZM models or was implemented during front travel upgrades directly in the field. In the general scheme of our two-wheel front travel system, this part acts as the main rotation support assembly that absorbs axial loads. The bearing is installed on the lower, smooth (non-threaded) shank of the lifting screw ZP 01.070 and is positioned directly in the contact zone between the shaft and the horizontal flange of the internal fork ZP 01.040.

Technical Specifications of Thrust Bearing 8104

• Standard / Marking: 8104 (according to GOST 520-2002)
• Type: Ball, single-direction thrust
• Application: Front two-wheel travel height adjustment mechanism (ZP 01.020) for ZM-60U, ZM-90U, ZM-120U, ZMB-90U, ZMB-120U units
• Installation location: Lower shank of lifting screw ZP 01.070
• Quantity per unit: 1 pc.
• Related fastening elements: Washers 20 GOST 11371-68 (2 pcs. for compression), cotter pin 5x50 GOST 397-79

By its engineering design, the 8104 bearing is intended exclusively to absorb significant unidirectional axial (vertical) loads. In the lifting mechanism's kinematic scheme, it serves as the primary support point through which the static weight of the massive frame is transferred from the screw ZP 01.070 to the moving internal fork ZP 01.040.

Installation of this part requires following the factory assembly sequence — according to the modernized two-wheel travel scheme, the bearing is installed on the smooth lower screw shank as a "sandwich": it is clamped between two flat steel washers, where the top one rests on the transition shoulder of the shaft, and the bottom one lies directly on the horizontal flange of the internal fork. This arrangement creates perfectly flat contact surfaces for the bearing races, protecting it from misalignment and uneven pressure distribution.

At the bottom, this entire support assembly is secured with a 5x50 cotter pin, but it is important to understand that the pin does not participate in holding the machine's weight — it acts solely as a safety device. Its function is to keep the bearing and washers on the screw shank and prevent the shaft from jumping out of the fork opening if the operator winds the screw drive to its extreme upper position.

The presence of the thrust bearing 8104 fundamentally changes the physics of the mechanism's operation compared to classic grain loaders. Instead of destructive "metal-on-metal" point friction between the shaft, bushing, and fork, the bearing absorbs all resistance onto its balls. This guarantees easy, smooth rotation of the manual drive without binding or slipping, allowing the operator to adjust the feeder working clearance above the threshing floor surface without excessive physical effort.

Related Components of the Lifting Assembly

Since the thrust bearing 8104 works in a rigid kinematic connection with other elements of the height adjustment mechanism, the condition of the following adjacent parts should be checked during its replacement or technical inspection:

• Screw ZP 01.070
• Internal fork ZP 01.040
• Washer 20 GOST 11371-68 (2 pcs.)
• Cotter pin 5x50 GOST 397-79

One of the core ideas in the design of modernized grain loaders by Zavod Moroza is the deliberate avoidance of rare or specific parts where it is not justified by engineering necessity. We design assemblies with a maximum focus on using modern, standardized, and widely available consumable parts.

The thrust bearing 8104 is a clear practical example of this approach. It is an ordinary, mass-produced part, and if the bearing fails during intensive threshing floor operations (e.g., due to systematic lack of lubrication or critical overloading), you will not have to stop grain loading and wait for days for the delivery of a "unique" spare part from the factory. Such a bearing should always be available at the nearest auto parts store, not to mention the mechanic's own repair stocks or the farm's workshop, as it is widely used in both automotive and various agricultural machinery. Such repairability is critical during the peak season. Using standardized consumable components allows the operator to replace a destroyed element literally "on the spot," quickly returning the lifting mechanism to its initial smoothness and avoiding expensive equipment downtime.

Buy Thrust Bearing 8104 as Part of a Repair Kit

Although the thrust bearing 8104 itself is a commonly available part, its failure rarely leaves neighboring elements unaffected. If the bearing disintegrates under load, the steel support washers often deform or bend, and the locking cotter pin may be sheared or lost. Therefore, for a technically sound and quick restoration of the assembly, we recommend not buying just the bearing, but ordering it as a ready-made installation kit, which includes at least two support washers (Washer 20) and a new cotter pin (5x50). Additionally, it is worth carefully inspecting the lower shank of the screw ZP 01.070 and the horizontal flange of the internal fork — if prolonged operation with a destroyed bearing has led to deep metal wear on the shaft itself, a simple bearing replacement will not help, as it will wobble on the "stripped" axle. In such cases, at Zavod Moroza, you can immediately purchase a new power screw, an internal fork, or a fully assembled front travel lifting unit to resolve the repair issue comprehensively.

Contact our sales department to select components — we understand the technical nuances of machines from different years of production and will help you find optimal parts taking into account the structural features of your specific grain loader. Get all necessary spare parts from a single source to restore easy rotation to the lifting mechanism and permanently eliminate jamming issues.