CAT 112-3042 Recoil Spring Retainer

CAT 112-3042 is a Caterpillar original parts buffer spring stop (fixer) used for axial positioning and anti-loosening of the buffer spring assembly in tracked bulldozers. It is compatible with the suspension systems of models such as D7R/D7R II. The following is precise original parts information:

Core Technical Parameters
Item Details
Part Model: CAT 112-3042 (1123042) Buffer Spring Stop, Weight: Approx. 28 kg (61.73 lb), Suitable for tracked bulldozer suspension buffer spring positioning

Core Material: 4140 alloy steel, overall heat treated (hardness HB 280-320), thread surface nitrided for wear resistance and anti-galling, suitable for heavy-duty impact conditions

Key Dimensions: Inner diameter 203.2 mm (8.00 in), Outer diameter 234.7 mm (9.24 in), Length 197.1 mm (7.76 in), Thread size 9-1/4 – 4 ACME, compatible with buffer springs with an inner diameter of 203 mm and an outer diameter of 305 mm.

Structural Features: Cylindrical structure with internal threads, one end with a flange (12 mm thick), thread precision 6H. The flange face fits snugly against the buffer spring end face, and the spring is fixed by the thread preload. It is suitable for axial positioning and anti-loosening, and can withstand the reciprocating impact load of the buffer spring.

Compatible Models: CAT D7R/D7R II/D7R XR/D7R LGP tracked bulldozers, 572R/572R II tracked earthmoving machines (suspension buffer spring assembly)

Accessories: Compatible buffer spring 112-3043, spring seat 112-3044, lock nut 112-3045, thrust washer. 112-3046 Core Functions and Installation Points

Buffer Spring Positioning: Made of tempered alloy steel, the buffer spring is pre-tightened with threads to prevent axial movement of the spring. This ensures the suspension system’s cushioning and shock absorption performance, suitable for absorbing impact loads during the travel and operation of tracked bulldozers.

Thread Anti-Loosening Design: ACME trapezoidal thread with a 29° thread angle provides a large bearing area and strong anti-loosening ability after pre-tightening, suitable for high-frequency vibration conditions, preventing suspension failure caused by spring loosening.

Installation Specifications: Clean the threads and flange surfaces to remove oil and rust. Apply an anti-seize agent (such as CAT 5P-3931) to the threads to prevent seizing after installation.

Tighten with a torque wrench to a torque of 850-950 N・m (626-701 lb-ft), ensuring the flange surface and spring end face are in full contact without gaps. After installation, check the exposed thread length (≥5 mm) to ensure proper pre-tightening.

Equipped with thrust washers and lock nuts, providing secondary anti-loosening protection and ensuring long-term operational reliability.

Maintenance Recommendations: Check thread preload torque and flange sealing every 1000 working hours. If loosening is found, retighten to the specified torque.

If threads are damaged or flange surface is deformed, replace with genuine parts immediately to prevent buffer spring positioning failure.