TTB Questions and Meaurements

AssBurns

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I'm looking for some opinions and some tech info on the Ford Bronco Dana 44 TTB suspension. A quick idea of what I'm looking to do. I have a 3rd gen 4Runner that I am considering doing a TTB swap in. I want to build a dual purpose vehicle that can take the desert at higher speeds while still being able to do some mild crawling/ technical stuff. Not trying to build something to take to the Hammers but something that can still handle some mild crawling. The goal would to keep a semi-low COG while keeping some good up travel (around 8" or so). I know that these front ends are capable of pulling 16' of clean, usable travel so that 16' number is what i'm shooting for. I have a few questions and would like to ask for some measurements from a bronco to get a better idea of things. I have some ideas in my head and I don't have a Bronco to take measurements on right now.

First, what exactly limits a Bronco on the up travel besides fender clearance? I can make room for tires. I'm assuming the frame is the first thing to limit up travel? How much lift on a Bronco is needed to get roughly 8" of up travel?

I see that most of the LT guys like to do a Cut and Turn on the beams instead of Drop Brackets. The cut and turn sounds like it causes more stress on the u-joints. In crawling situations, additional U-joint stress is not good. The drop brackets cause more stress on the frame, but what if I build the crossmember and beam mounts to have about 2" drop from what a stock Bronco has. This should be plenty strong and not much extra stress on the frame. If I need to correct the camber for a higher ride height, I could always do the cut and turn at the LBJ. How much do stock beam mounts hang below the bronco frame rails?

One of the reasons I'm thinking of going for more of a drop bracket style is because I hear that when you have your beam pivots mounted up higher, you get jacking on off camber/ side-hilling situations. I'm sure there are other reasons to go one way or the other, so I'd like to hear your opinions on this. How does the handling and cornering get effected between a drop bracket style and cut n turn style lift?
 

partybarge_pilot

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Frame limits uptravel. 8" of uptravel is pretty easy. Cut and turn does not have any impact on U-joints if done correctly. Drop down brackets, NO.

I might be wrong, but isn't the T-case drop on the wrong side on the 4 runner?
 

partybarge_pilot

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The thing that will hurt you is frame width. The diff will not clear at full bump. Inside of the frame rails is about 32" on a Bronco/F150. A little frame clearancing would go a long way.........
 

AssBurns

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Frame limits uptravel. 8" of uptravel is pretty easy. Cut and turn does not have any impact on U-joints if done correctly. Drop down brackets, NO.

I might be wrong, but isn't the T-case drop on the wrong side on the 4 runner?

The thing that will hurt you is frame width. The diff will not clear at full bump. Inside of the frame rails is about 32" on a Bronco/F150. A little frame clearancing would go a long way.........

The 3rd gen 4runner has a drivers side drop, so I'm good there. Thanks for the info on the frame width. I actually meant to ask that but forgot. My frame width is roughly 31" on the outside of the frame rails and around 27' on the inside. It would definitely require some frame clearancing then. Not a huge issue but that will definitely take some extra work.

As for the drop brackets, I wouldn't actually have drop brackets, just incorporate around 2" lower beam pivots into a custom crossmember and beam mounts. Besides stress on the frame, why not drop the beam pivots down a couple inches then Cut and turn the difference if needed?
 

Moss2

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One reason the drop brackets are not desirable is if you drop it 2" you have 2" or more less ground clearance at bump.
 

AssBurns

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That makes sense then.

What about the differences in handling between the two options? I’d assume side-hilling and cornering would be different between the two. I’d assume that the cut and turn option has less body roll but I could be wrong.


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AssBurns

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Another thing to think about is the steering box. Since the frame rails on the 4Runner are narrower and probably not enough room for a steering box on the inside of the frame rails. I could fit a steering box on the outside of the frame rails then do a double swing for steering.

From a Tacoma SAS pic I found. I'm thinking the same mounting location.
2004-toyota-tacoma-4x4-control-arms.jpg

insightful pic but found a pic off a box mounted on the outside of frame rails with Double Swing Steering.
Steering Box Double Swing.jpg

Thoughts?
 

partybarge_pilot

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With longer than stock radius arms, you can probably get away with inside the frame and single swing. There is a steering box option that will take up a lot less room.
 

partybarge_pilot

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Astro van box mounted with the shaft up just like it is in the van, it will be the D-side swinger.



Then you can either run a couple of U-joints to connect to the steering shaft or use a 90* box like used in Passports/Rodeo's/others......

 

Dirty Harry

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How much of a killjoy am I being if I state the obvious and say that you can buy an entire Bronco for less than this conversion is going to cost?

I have a friend with TTB under his Cherokee and it is super cool for sure, but it doesn't really make economic sense.
 

AssBurns

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Tacoma and 4Runner frames are almost identical up front. Looks like that guy cut the stock frame off and welded on the bronco front end. That might actually be a really good option to consider. Thanks for sharing that with me. I couldn't find anything about doing a TTB swap on a toyota when I searched.
 

AssBurns

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How much of a killjoy am I being if I state the obvious and say that you can buy an entire Bronco for less than this conversion is going to cost?

I have a friend with TTB under his Cherokee and it is super cool for sure, but it doesn't really make economic sense.
Well a bronco would be cool, especially with the V8 but I don't want a heavy, wide body. I like to get myself into some pretty tight situations that full width bodies would either not fit or would just get hammered. I'm looking to have a wider track width while still having the narrow body to help navigate through the tighter sections.
 

partybarge_pilot

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Well a bronco would be cool, especially with the V8 but I don't want a heavy, wide body. I like to get myself into some pretty tight situations that full width bodies would either not fit or would just get hammered. I'm looking to have a wider track width while still having the narrow body to help navigate through the tighter sections.

I'm right there with ya buddy!

If you want to go full retard. ZFG SXS build
 
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