Topic: Dual case gear upgrade question

[Zukyota77]

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?

[OVRAROK]

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.

[Zukyota77 [OP]]

My understanding is it is 21 spline. It is a Marlin adapter. So a 23 spline coupler and the gear set should get me fixed up. Anything need to be done to the first case? And I appreciate the response and guidance!

I will do all the clearance and install myself. I just would like to get everything I need the first time. I am trying to figure all this Toyota stuff out!

Here is what I’m looking at…
https://www.marlincrawler.com/product/4-701-xd-gear-kit-23-spline

[OVRAROK]

Should be good to go. 

[Zukyota77 [OP]]

So last question, is the 23 spline coupler you referred to in the kit that I linked or is that something separate I need to buy? I’m not seeing that on the Marlin site. If it is there any chance you could post the link? 

Thanks again for your help!

[OVRAROK]

You need to look at the adapter you have, see if you can find some markings. An example would be: MC07. Then I would call MC, to see if they have a 23 spline coupler for your adapter. Is the adapter anodized red? If so, that's the MC08. Good luck.

[blackdiamond]

The 23-spline coupling with a certainly the way to go, but many of us have successfully run a 21 spline coupler with 4.7:1 gears in the rear case.  I drive smart and easy so maybe that the secret to my success.

[Gnarly4X]

I drive smart and easy so maybe that the secret to my success.

Unlike the new Toyota Tacoma TV ad where they drive STUPID AND RECKLESS! 

Gnarls.