John Deere – 1023E, 1025R and 1026R – Inspect Oil Pump: 3TNV76 and 3TNV80

[1] – Remove timing gear cover. (See Remove and Install Timing Gear Cover in this Group.)

[2] – Remove the eight screws (A) from oil pump cover (B) and remove cover.

[3] – Remove inner rotor (C) and outer rotor (D) and check for wear or damage. Check inside
of cover for wear or deep scratches. Replace any worn or damaged parts.

[4] – Inspect inside of oil pump cover for grooves or deep scratches. Replace cover if worn or damaged.

[5] – Remove relief valve cap (E), spring (F), and valve (G). Inspect all parts for wear or damage. Replace any worn or damaged parts.

[6] – Measure clearance between outer rotor (H) and timing cover (I) with a feeler gauge (J).
If clearance exceeds wear limit, replace timing cover and both rotors.

[7] – Measure between high spots of inner and outer rotors with a feeler gage. If clearance exceeds specification replace rotors.

[8] – Place a straight edge (K) across timing gear cover bosses. Measure gap between edge of timing gear cover and the rotors with a feeler gauge (L). If clearance exceeds wear limit replace timing gear cover and rotors.

[9] – Assemble in the reverse order of disassembly.

[10] – Apply medium strength thread locking compound to oil pump cover screws and relief valve cap when installing.