Proper break-in of your new ring and pinion set is critical to gear longevity. Improper break-in creates excessive heat that reduces gear life or causes failure.

For the first five times driving on your new differential, limit driving to 20 minutes with at least 30 minute breaks in between to allow the differential to cool. 

After these 5 initial "heat cycles", for the first 500 miles, avoid hard acceleration, towing, and heavy loads. Keep driving intervals to 45 minutes with 30-minute cool-downs. At 500 miles, replace the differential break-in oil; you may then use standard or synthetic oil. (Do not use synthetic oil during initial break-in.)

After 500 miles, you can tow or haul, but treat the first 100+ miles of new loading like initial break-in. These loads generate heat that can damage the developing hard facing.

Overheating will be evident on inspection and voids the warranty. Contact us with any questions.

Something to consider before you stab your nice& new, clean& shiny, unbroken diff into your axle is the amount of debris left behind by broken or failing differentials. 

It is 100% necessary to completely clean the interior of the axle housing, including the tubes and the area behind the sheet metal oil baffles (found on either side of the differential on rear axles). Remove all metal fragments from previous breaks, as well as any mud, moisture, dust, or other debris.

Debris embedded in gears or bearings will be evident on inspection. Failure to properly clean and prepare the axle housing for your new differential will lead to premature failure and will void any warranty.

Yotamasters differentials require no core charge, we use brand new components*, so there is no need to send us your old differential, and you won't be charged a core fee.

So feel free to keep your old diff as a spare, loan it to a buddy, sell it on facebook marketplace, or make some sick yard art. 

*some differentials built in the "open" configuration will utilize a fully inspected, previously enjoyed, used carrier where brand new is not an option.

Here are some notes on fitment, please call to confirm what differential your project needs if you are not sure as this is not an exhaustive list.

• 4 Cylinder differentials originally came in 1979-1995 4x4 Pickups and 4Runners with a 22R/22RE
• V6 differentials were equipped in Pickups and 4Runners starting in 1986 with vehicles equipped with a 22R-TE, and then Pickups and 4Runners through 1995 with 3VZE engines.
• All 4Runners 1996-2009, all GX470, and Fj Cruisers from 2007-2009 have a V6 8" rear differential.
• 6 lug Tacomas from 1996-2015 not equipped with a factory e-locker will have the 8.4" differential. 
• 2000-2006 Tundra and 2001-2007 Sequoia will have an 8.4 rear diff
• T100s came with an 8.4 rear diff
• 2016-2023 3rd Gen Tacomas without a factory E-Locker came with V6 8" rear differentials.

4 cylinder and V6 differentials are functionally the same differential. They have interchangeable bolt patterns, essentially the same ring and pinion, and both take 30 spline axle shafts.

The V6 differential differs from the 4Cyl by having far larger bearings and a thicker, stronger 3rd member housing. This means ordering a V6 differential for your project that originally had a 4Cyl diff is a considerable upgrade in strength, and is what we recommend if you are building a crawler.

High pinion differentials use the bigger, stronger V6 components, but also have a reverse cut ring and pinion. This affords greater ground clearance, better driveshaft angle, and more strength in a front axle. High pinion differentials have the same bolt pattern as any other 8" diff, but should never be used in a rear application. The gearset is far weaker running in a rear axle and cannot oil properly. A high pinion diff in a rear axle will fail.

We use and recommend Conventional GL5 80w-90 here. This is typically the most affordable gear oil you can find at your local auto parts store, and does everything gear oil should. 

Synthetic is not to be used during the 500 mile break in procedure. After the break in, synthetic can be used if desired. If you are driving a higher powered rig, or you have a later model Toyota where the differential is undersized from the factory, like 4th Gen 4runners, FJ Cruisers, and GX470s, you might see some benefit and lower differential temps from running synthetic after break in.

Extremely thick gear oil, in the 140 Weight range, is not recommended. We have seen oil starvation in brand new diffs due to the lack of oil flow with high viscosity oil, especially in colder climates.

Differentials are built to order, so 2-3 weeks from when the order is placed is the typical lead time.

We keep a small number of differentials in stock in the more commonly ordered configurations, but please call to confirm and get a more accurate lead time. 

Shipping is a flat $100 per differential to the lower 48 states, using UPS Ground. For shipping outside of the lower 48, please call so we can give you an estimate. 

Customers local to Southern California may feel free to select in store pickup at checkout and save that $100, but please be aware the 2-3 week lead time will still apply if the differential is not in stock.

Due to the custom nature of the product and being built to order, we cannot accept returns on any differentials.

Please call us to confirm whether the configuration you are considering will be the correct fit for your project. 

Let us get you dialed with the right parts the first time around!