Yukon Gear Master Overhaul Kit For New Toyota Clamshell Design Front Reverse Rotation Diff

Complete Overhaul Solution for Toyota 8-Inch IFS Clamshell Front Differential

The Yukon Gear Master Overhaul Kit (YK TLC-REV-B) covers every consumable component needed for a full rebuild of the Toyota 8-inch IFS clamshell reverse-rotation front differential found in 4WD Tacoma, 4Runner, and FJ Cruiser models. Yukon engineers this kit around Timken carrier and pinion bearings selected for the load ratings that match Toyota's part-time and full-time 4WD drivetrains. Because every small part is included, installers can complete the job without sourcing individual shims, seals, or hardware separately, reducing downtime and eliminating the risk of mismatched components.

YK TLC-REV-B is engineered for the clamshell IFS reverse-rotation differential only. Confirm your axle uses the SD20B clamshell housing before ordering. This kit is not compatible with Toyota's older conventional-rotation front differentials or solid front axle applications.

What's Included

• Carrier bearings and races (Timken)
• Pinion bearings and races (Timken)
• Pinion seal
• Complete shim kit
• Ring gear bolts
• Pinion nut
• Crush sleeve
• Thread locker
• Marking compound and brush
• Silicone sealant

Specifications

Vehicle Fitment

Why Timken Bearings

Timken is the original equipment supplier for many Toyota differential applications. Their tapered roller bearings are manufactured to tight tolerances and carry an SAE-rated load capacity that exceeds the demands of street and moderate off-road use. Choosing a rebuild kit with Timken components rather than off-brand alternatives reduces the risk of premature failure and eliminates the need to verify bearing compatibility separately.

Differential Identification

The Toyota 8-inch IFS clamshell front differential was introduced in the 2003 4Runner and 2005 Tacoma alongside the new independent front suspension. The clamshell housing is identified by its split carrier casting and reverse-rotation ring gear. If your vehicle has a solid front axle or an older conventional-rotation front differential, this kit does not apply. Check the axle tag or compare your housing casting to confirm the SD20B application before purchase.

Frequently Asked Questions

What vehicles does this differential master overhaul kit fit?
This kit fits 2003 and newer Toyota 4Runner models equipped with 4WD and the 8-inch IFS clamshell front differential, 2005 through 2023 Toyota Tacoma 4WD models with the same axle, and 2007 through 2014 Toyota FJ Cruiser 4WD. The full vehicle-by-vehicle fitment is listed in the table above. Always confirm your axle type before ordering.

What is the difference between the master overhaul kit and a bearing install kit?
The master overhaul kit (YK TLC-REV-B) includes everything in the bearing install kit plus the shim kit, ring gear bolts, pinion nut, crush sleeve, thread locker, and silicone. If you already have your shims dialed in from a prior build and only need bearings and seals, a bearing install kit (BK TLC-REV-B) saves some cost. For a first-time rebuild or any build where the carrier position is being reset, the master kit is the correct choice.

Is this kit compatible with the reverse-rotation differential only?
Yes. The clamshell IFS front differential introduced in 2003 uses a reverse-rotation ring and pinion. This kit is engineered specifically for that application. It will not work with conventional-rotation Toyota front differentials used in earlier trucks and SUVs.

Does this kit include a shim kit?
Yes. A complete shim kit is included along with Timken carrier and pinion bearings and races, pinion seal, ring gear bolts, pinion nut, crush sleeve, thread locker, marking compound, and silicone.

What warranty does this kit carry?
Yukon Gear covers this kit with a lifetime limited warranty. Under the Magnuson-Moss Warranty Act, installing an aftermarket differential rebuild kit does not void your vehicle's drivetrain warranty as long as the part is not proven to have caused a failure.

Can I rebuild my front differential myself, or do I need a shop?
A front differential rebuild requires proper setup tools, a dial indicator, and experience with ring and pinion pattern reading. The job is achievable for an experienced DIY mechanic, but gear contact pattern and bearing preload must be set correctly or premature wear will result. If you have not done this type of build before, having a qualified drivetrain shop perform the rebuild is strongly recommended.

Do I need any special tools beyond what comes with the kit?
Yes. You will need a bearing press, bearing race driver set, dial indicator with magnetic base, pinion depth gauge, and a torque wrench. The marking compound and brush included in the kit are used for reading the gear contact pattern during setup.

How do I know if my front differential needs a rebuild?
Common indicators include whining or growling noise from the front axle under load, excessive differential play, metal particles in the differential fluid, or a differential fluid that has turned dark with a burned smell. Inspect the ring and pinion for scoring or pitting when the axle is open to confirm whether bearings alone or a full rebuild is needed.

Does the kit work with aftermarket ring and pinion gear sets?
Yes. The Timken bearings included in this kit are compatible with both OEM-spec and aftermarket ring and pinion gear sets for the Toyota 8-inch IFS clamshell application, as long as the gear set matches the correct differential rotation and bearing dimensions.

Is the TLC-REV-B the same as the BK TLC-REV-B?
No. YK TLC-REV-B is the full Master Overhaul Kit. BK TLC-REV-B is the Bearing Install Kit, which includes bearings, races, and seal but not the full shim kit, hardware, or thread locker. For a complete rebuild from scratch, the YK master kit is the correct part.

Installation Instructions

Differential rebuild work requires a clean workspace, proper tools, and careful attention to bearing preload and gear contact pattern. The following steps are a general guide. Always consult the factory service manual for your specific vehicle.

1. Drain the differential fluid and remove the front axle shafts and carrier assembly per the factory service manual procedure.
2. Inspect the ring and pinion for wear, pitting, or scoring. If the gear set is being reused, clean and dry all surfaces.
3. Press out all old bearings from the carrier and pinion using a proper bearing puller. Do not hammer bearings off the gear set.
4. Install the new Timken carrier bearing races into the differential housing using a race driver. Seat them fully and evenly.
5. Press new Timken pinion bearings onto the pinion gear. Install the pinion seal and set pinion depth using the included shims and a dial indicator.
6. Install the ring gear with new ring gear bolts from the kit. Torque bolts to the factory specification in a cross pattern.
7. Set carrier bearing preload and check the gear contact pattern using the included marking compound and brush. Adjust shims as needed to achieve the correct pattern.
8. Apply thread locker to the pinion nut per specifications. Torque the pinion nut to achieve the correct pinion bearing preload.
9. Apply silicone sealant to the differential cover mating surfaces. Reinstall the cover and torque the bolts in a cross pattern.
10. Fill with the correct Toyota differential fluid to the proper level. Reinstall axle shafts and perform a test drive to verify no abnormal noise.

WARNING: This product can expose you to chemicals including lead and lead compounds, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.