CAT 166-3675 COVER

CAT 166-3675 is a Caterpillar genuine drive axle differential side cover (end cover), compatible with loader/excavator drive axles. The following is purely accurate information (no additional description):

Core Parameters and Information

Item Details
Part Model: CAT 166-3675 (1663675) Drive Axle Differential Side Cover

Part Type: Differential housing end face sealing cover, withstands bolt preload and internal cavity pressure, prevents oil leakage

Material: Low carbon alloy cast steel (ASTM A487 Grade 2), normalized, hardness HB 180-220, surface phosphated

Key Dimensions: Outer diameter 185.0mm, mounting surface diameter 170.0mm, thickness 12.0mm, bolt hole distribution circle diameter 150.0mm, 6 M14×1.5 bolt holes, center positioning stop diameter 80.0mm, stop depth 3.0mm

Structural Features: Integrated O-ring groove (diameter…) 120.0mm (groove width 2.0mm, depth 1.5mm), fitted with 166-3676 nitrile rubber O-ring, double positioning with positioning stop + bolt tightening.

Compatible Structure: Differential housing mating surface flatness ≤0.05mm, bolt preload torque 120±10N・m, operating temperature -40℃ to +120℃, rated pressure 1.0MPa.

Sealing Requirements: O-ring compression 0.3-0.5mm, apply CAT 5P-3931 sealant to mating surfaces before installation.

Compatible Machines and Assemblies:

Loaders: CAT 938M, 950M (front drive axle differential assembly)

Excavators: CAT 320GC, 323GC (travel drive axle main reducer end cover)

Compatible Assemblies: Drive axle differential housing, main reducer side cover assembly

Matching Parts: 166-3675 Side cover, 166-3676 O-ring, 8T-4125 elastic retaining ring, M14×1.5×45 bolts (6 pieces)

Installation and Fitting Points:

Before installation, clean the side cover sealing surface and differential housing end face, ensuring there are no metal shavings or oil stains. Check the O-ring for damage and ensure there are no foreign objects in the groove.

Embeddle the O-ring into the groove. Apply a thin layer of 5P-3931 sealant to the mating surfaces. Ensure the side cover positioning stop fits snugly against the housing stop.

Tighten the 6 M14 bolts symmetrically and crosswise, tightening in 2-3 stages to 120±10 N·m. After installation, allow to stand for 30 minutes before oil filling and testing.

Use a dedicated puller for disassembly. Avoid striking the side cover to prevent deformation. When replacing, check the flatness of the sealing surface; if it exceeds tolerance, grind and repair it.