Overview
The ZF 4651.199.026 LOOSE PARTS kit is a critical service component engineered specifically for the WG 100 series transmission family. This OEM genuine assembly contains the necessary loose hardware and fasteners required to secure internal hydraulic circuits and valve body components within the transmission housing. Positioned directly within the main control bore, the 4651.199.026 ensures proper sealing and alignment of the shift valve assembly, preventing cross-leakage between pressure channels. When replacing the TRANSMISSION HOUSING or performing a deep overhaul, this SKU must be installed to maintain OEM-specified clamping forces and fluid routing integrity.
Symptoms of Failure
- Erratic shift timing and delayed engagement — Worn or missing loose parts cause valve body misalignment, leading to inconsistent clutch pack application during acceleration.
- Internal hydraulic pressure loss — Degraded components within the 4651.199.026 kit allow pressurized ATF to bypass seals, resulting in soft shifts and eventual transmission slippage under load.
- Visible oil seepage around the valve body cover — When the loose parts lose their dimensional integrity, the mating surface between the O-RING and the HOUSING becomes compromised, producing external leaks.
- Intermittent neutral conditions — Loose fasteners or spacers that have fatigued can cause the shift rail to dislocate, temporarily interrupting power flow to the output shaft.
Technical Specifications
| Parameter | Specification |
|---|---|
| OEM Part Number | 4651.199.026 |
| Material Composition | Hardened alloy steel with zinc-nickel plating |
| Overall Dimensions | 85 mm x 45 mm x 12 mm (kit assembly) |
| Unit Weight | 0.18 kg (0.40 lbs) |
| Thread Pitch | M6 x 1.0 (primary fasteners) |
| OEM Reference | ZF Friedrichshafen AG |
| Torque Specification | 12 Nm ± 1 Nm (dry) |
Compatibility
This genuine ZF 4651.199.026 LOOSE PARTS kit is designed for the WG 100 series, but its application extends to several ZF powershift transmission models sharing the same valve body architecture. Compatible transmissions include the WG180, WG200, WG120, and WG150 series. It is also suitable for select WG 100 variants used in construction loaders and agricultural tractors. Always verify the HOUSING part number against your transmission serial plate before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4651101007 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4651301029 | HOUSING | Intermediate support housing for clutch pack |
| 0634303928 | O-RING | Static seal for hydraulic passages |
| 4651301024 | HOUSING | Rear housing for output shaft assembly |
| 4651203002 | SCREEN SHEET | Fine mesh filter for valve body inlet |
| 4651303005 | SCREEN SHEET | Secondary filter for lubrication circuit |
| 0636101032 | CAP SCREW | Fastener for housing attachment |
| 0630361028 | SEALING CAP | Port closure for pressure test points |
| 4475280060 | SCREW PLUG | Threaded plug for drain or fill ports |
| 0634303312 | O-RING | Seal for screw plug interface |
