Tuff Country 55913 Front Differential Drop Kit for 1999-2006 Toyota Tundra 4WD, 3.4L V6 and 4.7L V8

The Tuff Country 55913 is a front differential drop kit built specifically for the 1999-2006 Toyota Tundra 4WD running a 2 to 6 inch lift. When you lift your first-gen Tundra, the front differential stays at stock height while the suspension drops, pulling the CV axles into a steep downward angle that causes vibration, premature joint wear, and drivetrain noise. This kit relocates the differential downward to restore proper CV axle geometry, eliminating axle bind and extending the life of your front drivetrain. Made in the USA and backed by a limited lifetime warranty, this is the correct fix for any lifted 1999-2006 Tundra 4x4.

What's Included

• 2 front differential drop spacers with integrated bushings
• 2 longer replacement mounting bolts
• All necessary nuts, washers, and hardware for installation

Why Your Lifted Tundra Needs a Differential Drop

Lifting your 1999-2006 Tundra 4x4 lowers the suspension relative to the frame, but the front differential stays bolted at its factory mounting position. The result is a steep downward angle on both inner CV joints, well outside the factory design range. At lift heights between 2 and 6 inches, this binding causes:

• Steering vibration and shimmy at highway speeds
• Premature CV axle and inner joint failure
• Accelerated wear on front differential seals
• Clicking or popping sounds during tight turns at low speed

The drop spacers bolt between the differential mount and the crossmember, lowering the entire differential assembly to restore factory CV axle angles. The install is bolt-on, requires no cutting or welding, and takes under an hour with basic hand tools.

Fitment for 1999-2006 Toyota Tundra 4WD

This kit fits the 1999-2006 Toyota Tundra in 4WD configuration only. It is not compatible with 2WD Tundras. Both the 4.7L V8 and 3.4L V6 engines are covered. The differential drop mounts to the front differential crossmember, a location unaffected by engine size. Confirm you have a 4WD model before ordering.

Full Specifications

Warranty and Your Factory Coverage

The Tuff Country 55913 is backed by a limited lifetime warranty against defects in materials and workmanship. As a mechanical suspension hardware kit, it carries no emissions involvement and CARB does not apply.

Under the federal Magnuson-Moss Warranty Act, a dealer or manufacturer cannot void your factory warranty simply because you installed an aftermarket suspension component. They must prove the aftermarket part directly caused the specific failure being claimed.

California residents: This product contains chemicals known to the State of California to cause cancer and reproductive harm. See www.p65warnings.ca.gov.

Compare: Tuff Country Differential Drop and Carrier Bearing Drop Kits for Toyota Trucks

Tuff Country makes differential drop and carrier bearing drop kits for the entire Toyota truck lineup. Make sure you select the correct part for your specific vehicle and generation:

Installation Overview

This is a bolt-on kit that requires no cutting, no welding, and no drilling. A basic socket set and a floor jack or lift are all you need. Most installs take under an hour.

• Safely lift and support the front of the vehicle
• Support the front differential with a jack stand before removing factory bolts
• Remove the factory differential mount bolts
• Install the drop spacers between the differential and the crossmember
• Install the longer provided mounting bolts and torque to spec
• Lower the differential onto the spacers and verify CV axle angles are corrected

About Tuff Country EZ-Ride Suspension

Tuff Country EZ-Ride Suspension has been designing and manufacturing lift kits and suspension components in the USA since 1981. Their components are engineered to work together as a system, and individual hardware components are built to the same standards as their full lift kits. Every Tuff Country product is backed by a limited lifetime warranty.

Frequently Asked Questions

Does the Tuff Country 55913 work with any brand lift kit, or only Tuff Country lifts?
It works with any brand of lift kit in the 2 to 6 inch range. While it is the OEM-equivalent component inside Tuff Country's own Tundra lift kits, the spacer design is purely mechanical and will restore correct CV angles regardless of which brand's lift is installed.

What year range does the 55913 fit exactly?
The 55913 fits the 1999-2006 Toyota Tundra 4WD. The 2007 and newer second-generation Tundra uses a completely different differential mounting setup and requires a separate part. For 2007-2017 Tundras, see Tuff Country part numbers 50303 or 55914.

Does the 55913 fit both the 3.4L V6 and 4.7L V8 first-gen Tundra?
Yes. The differential drop mounts to the front differential crossmember, a structural location that is identical across both engine options on the 1999-2006 Tundra. Engine displacement has no effect on fitment for this kit.

Will the 55913 fit a 2WD Toyota Tundra?
No. This kit is designed for 4WD Tundras only. A 2WD Tundra does not have a front differential or CV axles, so there is nothing to relocate.

How much lift do I need before a differential drop is required?
Most builders recommend a differential drop for any lift of 2 inches or more on the first-gen Tundra. The 55913 is rated for 2 to 6 inch lifts. If you are running more than 6 inches, contact Tuff Country directly to confirm compatibility before ordering.

What happens if I skip the differential drop on my lifted 1999-2006 Tundra 4x4?
Running a lifted 4WD Tundra without correcting CV axle angles puts the inner joints at an angle beyond their design limit. This accelerates wear on the CV axles, inner joints, and differential seals, and causes vibration and clicking during turns. Correcting it now with a differential drop is far less expensive than replacing CV axles or rebuilding a differential later.

Will installing this kit void my Toyota factory warranty?
Under the federal Magnuson-Moss Warranty Act, an aftermarket part cannot void your factory warranty unless the dealer can prove that specific part directly caused the failure being claimed. Installing a differential drop kit does not automatically void any coverage on your Tundra.

What is the correct part for a 2005-2023 Toyota Tacoma 4WD?
The Tacoma equivalent is Tuff Country part number 55912. The 55913 is specific to the first-gen Tundra platform and is not interchangeable with the Tacoma differential mounting.