ZF 0730.303.026 SHIM | OEM Genuine Part

Overview

The ZF 0730.303.026 SHIM is a precision-engineered OEM genuine part designed to establish critical axial clearances within heavy-duty ZF powershift transmissions. This thin, hardened steel shim sits between the differential housing and the bearing race, allowing technicians to fine-tune gear lash and preload during assembly or overhaul. By compensating for manufacturing tolerances and wear, the SKU 0730.303.026 ensures that the differential assembly rotates with minimal vibration and optimal load distribution. It is a non-serviceable wear item that must be replaced whenever the transmission is rebuilt to maintain factory-specified end-play tolerances.

Symptoms of Failure

When the ZF 0730.303.026 SHIM becomes crushed, corroded, or incorrectly sized, several distinct failure modes emerge. Excessive differential bearing noise during turns is a primary indicator, often described as a low growl or rumble from the axle housing. Premature wear of the taper roller bearing occurs because improper shim thickness allows axial movement, leading to brinelling of the raceways. Oil contamination from metal particles in the transmission fluid signals that the shim has worn through its surface hardening. Finally, erratic gear engagement in forward/reverse can result from the differential housing shifting position under load, altering the mesh pattern of the bevel gear set.

Technical Specifications

Parameter	Value
Part Number	0730.303.026
Material	Hardened Spring Steel (C67S)
Outer Diameter	68.0 mm
Inner Diameter	42.0 mm
Thickness	0.30 mm (selective fit)
Weight	0.012 kg
Surface Finish	Ground, deburred edges
OEM Reference	ZF 0730.303.026

Compatibility

This shim is a standard component in ZF’s modular powershift transmission family. It is directly compatible with the WG180, WG200, and WG211 series used in construction machinery such as wheel loaders, telehandlers, and graders. It also fits the 4WG-200 and 6WG-200 variants where the differential assembly requires precise axial shimming. Always verify the shim thickness against the service manual’s selective fit chart, as multiple thicknesses (0.20 mm to 0.50 mm) are available for the same bore diameter.

Installation Context

During a differential rebuild, the 0730.303.026 shim is installed directly behind the 0750117075: TAPER ROLLER BEARING on the pinion shaft. It works in conjunction with the 5838300626: DIFFERENTIAL HOUSING to set the correct preload. The shim also affects the alignment of the 5838109012: DIFFERENTIAL and the 2093209023: DIFFERENTIAL assembly. Using an incorrect shim thickness will cause rapid failure of the bearing and differential gears.

Related Components

Part Number	Name	Function
5838109012	DIFFERENTIAL	Distributes torque to axle shafts
0750117075	TAPER ROLLER BEARING	Supports pinion shaft radial/axial loads
2093209023	DIFFERENTIAL	Secondary differential assembly
5838300626	DIFFERENTIAL HOUSING	Encloses differential gear set
0631329088	SPRING PIN	Locks differential pinion shaft
5838300811	THRUST WASHER	Reduces axial friction on side gears
5838300721	AXLE BEVEL GEAR	Transfers power to axle shafts
5838300633	AXLE	Drives wheel hub assembly
5838300753	THRUST WASHER	Spacer for differential pinion gears
5838300818	THRUST WASHER	Axial support for differential cross shaft

Frequently Asked Questions

Q: Can I reuse the 0730.303.026 shim during a rebuild?
A: No. ZF specifies that all selective shims must be replaced with new parts during any differential overhaul. The shim undergoes plastic deformation during initial torqueing and will not provide accurate preload if reused.

Q: How do I select the correct shim thickness?
A: Measure the actual bearing bore depth and pinion gear height using a depth micrometer. Subtract the target preload clearance (typically 0.05-0.10 mm) from the measured gap, then select the shim that matches that calculated thickness. Always use the service manual for your specific WG model.

Q: Does this shim fit ZF 4WG-200 transmissions?
A: Yes. The 0730.303.026 is used in the differential section of 4WG-200, 6WG-200, WG180, and WG211 transmissions. Verify the housing bore diameter is 68 mm before installation.