Crawl Box for Different Tire Sizes?

I run 33's on my '12 (4.0 auto), but I've been considering getting a set of the 37x12.50 humvee take offs. My biggest issue is that I want to continue using the 33's for daily use and throw the 37's on for wheelin' trips but my gearing should be different for the two different sizes. The idea that came to me today is using a "crawl box" with a ratio suitable to switching between tires. Have it in 33" mode as it sits now, then engage the crawl box when I put 37's on to end up with a little lower gear ratio and hit the same sort of RPM's. I have been looking around and haven't seen any crawl boxes that have a ratio anywhere close to what I would need. Does anyone have any better ideas, or an idea of where I might find a crawl box suitable for what I want to do?

Yes, 37's are going to be real tough to clear, they're going to be heavy, I'm probably going to break a lot of stuff, and so on. I know. Please keep the comments related to gearing. Thanks!

 

its possible, but I cant think of a product.

they make over-drive splitter things. try these guys

https://www.gearvendors.com/mhfacts.html

 

best your going to do is regear for a tire size of like 35's. Crawlboxes offer substantial changes in gear ratios, the difference between the 33 tire size ratio and 37 isnt nearly that much.

btw good luck fitting 37's

 

All Pro's Brownie build and at least one other guy I can think of off the top of my head run them.

 

These things look interesting, although I don't see anything for Toyotas?

Gearing somewhere in the middle would be the easy way, but I'd really like to find something better. I'd be revving pretty high on the highway most of the time, and be a little sluggish with the 37's.

With a big enough hammer and enough cut off wheels you can accomplish anything. Also, I've seen it done.

 

What are you looking to spend? Could look at a Atlas 4 speed there custom made units it would give a 1:1 for 33's and custom ratio for 37's high range and 2 different lows. Looking at at least 4k for something like that.

I don't know if they can make a ratio between 1:1 and 2:1 as well

I'm geared to 4.56 on 35's, drove for awhile on 33's great and I'd like to get to 37's eventually with the wheeling I'm doing but will prob come with a sas.

Btw if your looking for some local info feel free to check out our BC Toyota 4wd group on Facebook.

 

Sounds like the perfect recipe for you to be the first guy with an 05+ to go dual transmissions.

Never seen anyone use a crawl box to accomplish what you want.
A crawl box either has 2.28:1 or 4.7:1. Normally you're at 1:1 in high range.
2.28:1 would be too low for highway use. You'd top out at 45, if you're lucky.
You'd need something like 1.5:1 crawl box gears.