I am new to the Toyota world and I need to ask a newbie question. The rig I bought has dual cases with 2.28 in both. I want to upgrade the back case to 4.7 gears. Besides the gear set, is there anything else I need to make this change?
Well, the adapter may be 21 spline. And yes, you could run 21 spline 4.7 gears. But it's recommended when install 4.7 in second case that you upgrade to 23 spline. Depending on brand of adapter. You may be able to purchase just the 23 spline coupler. At that point, you'll just need to grind inside of housing to clear the 4.7 gears. If you didn't want or feel comfortable doing, you could always purchase advance adapters crawl box. As it's already clearanced for the larger gear set.
