ISUZU 700P 4HK1 Change Lever Boot 1-79998913-1 OEM Fit

The Change Lever Boot with OEM numbers 1-79998913-1 and 1799989131 is a verified direct-fit replacement for ISUZU 700P / FRR / FTR / FVR / FSR series trucks equipped with 4HK1 / 6HK1 diesel engines. This boot is the critical protective element of the gear-shifting mechanism, installed between the base of the shift lever and the cab floor or transmission control housing. It seals the floor opening through which the shift lever passes, preventing dust, mud, oil, and noise from entering the cab while allowing unrestricted shift lever movement.

The change lever boot is a pleated (bellows-type) rubber cover fitted over the base of the shift lever. The upper end is secured to the lever by a clamp or retaining ring, and the lower end is fixed to the cab floor or control housing base. Its pleated structure allows the lever to swing in multiple directions through large angles during gear selection and shifting while maintaining a continuous seal.

The rubber compound must offer oil resistance, ozone resistance, temperature tolerance, and fatigue resistance to avoid tearing or hardening under frequent shifting and long-term use. The 4HK1 is a 5.2L inline-four diesel, and the 6HK1 is a 7.8L inline-six diesel, both widely used in ISUZU medium-duty trucks and construction machinery.

Replace the boot when any of these symptoms appear:

• Visible cracks, tears, or holes in the boot — rubber aging or mechanical wear breaks the seal, allowing dust and noise into the cab.
• Hardened or non-elastic boot — aged rubber cannot flex with the lever, potentially restricting shift movement or causing further tearing.
• Increased dust or road noise in the cab — a damaged boot leaves the floor opening unsealed, admitting road dust and mechanical noise.
• Oil or muddy water intrusion at the shift lever base — seal failure allows contaminants into the control mechanism area, accelerating wear.
• Boot dislodged from the clamp or retaining ring — loose installation or aged boot lip results in an incomplete seal.

1. Preparation: Remove the shift knob (if required) and the old boot's retaining clamp/trim ring. Clean the lever base and floor opening area.
2. Inspection: Inspect the lever and base for sharp edges, burrs, or corrosion. Check the new boot for shipping damage.
3. Installation: Align the lower end of the new boot with the floor/base opening, ensuring the pleats are naturally extended without twisting. Install and tighten the lower clamp/retaining ring. Slide the upper end over the lever and install the upper clamp/trim ring.
4. Function Check: Cycle through all gears to confirm the boot moves freely with the lever, without over-stretching, pinching, or dislodging.
5. Trim Reinstallation: Reinstall the shift knob and surrounding interior trim.
6. Road Test: Perform a road test to confirm smooth shifting and no abnormal dust or noise in the cab.

• Every 10,000 km or at each service: Inspect the boot for cracks, tears, or dislodgement.
• When increased cab dust or shift-area noise is detected: Inspect the boot immediately.
• When servicing the clutch or transmission-related components: Inspect the boot and replace if necessary.

• Standard Packaging: Sealed bag + moisture barrier + neutral box.
• Custom Packaging: Neutral box, color box, or customer-branded packaging.
• Suitable For: Truck repair shops, ISUZU parts distributors, fleet maintenance centers.
• Supply Capacity: Stable batch supply with batch-level quality reports available.
• MOQ: Small quantities accepted (quantity discounts available).