Dual Case Questions

[jkeith.w]

Frame rail height is possible....but you *may* have to cut into the trans tunnel to get a truly flat belly....unless you run something like FROR's plate style Xmember and make some other type of skid. Otherwise, you're looking at something like a 2" drop below the frame rail if you want a crossmember UNDER your tcases.....by that I mean your cases will likely be flush with the rail, but the Xmember will be an additional 1.5-2" thick....if that makes sense.

Yeah; I'll do something like FROR (but I'll have to make it, since I'll be clocked)
- and I'll likely do 2 of them (one for transmission)

- that's the only way I can see to pull it off.

 

[Sean K.]

Just ditch your stock case and do a NW Fab Blackbox to Ford NP205 and then don't worry about it. I'm in it right around $3k with adapter and shifters.

I disagree. The 205 is huge/heavy and 1.96:1 isn't much reduction. There was a company that was making something in the 3:1 range IIRC....but it was expensive enough I'd just do an Atlas if you needed that much strength. If you want ultimate beef and money is no object....get a Hero.

 

[Sean K.]

Yeah; I'll do something like FROR (but I'll have to make it, since I'll be clocked)
- and I'll likely do 2 of them (one for transmission)

- that's the only way I can see to pull it off.

There was a guy on Pirate that had the CNC file to do the old gear driven pattern.....wonder if anyone has it for the chain drive unit in your rig? Might be worth looking. Cost was only like $50 + shipping to have it cut out.

 

[Sean K.]

Question for you Keith.....

This is getting pretty involved in terms of a swap. Are you contemplating a SFA at some point? If so, the crossmember under the cases makes more sense as if you build it correctly, your 3/4 link can/should connect to it.

Just something to keep in mind.

 

[jkeith.w]

Question for you Keith.....

This is getting pretty involved in terms of a swap. Are you contemplating a SFA at some point? If so, the crossmember under the cases makes more sense as if you build it correctly, your 3/4 link can/should connect to it.

Just something to keep in mind.

Nope; just removing the issues I see with the truck as-is; save I've gotten sidetracked into dual cases. If I'm going duals, might as well clean up the undercarriage for the cost of 2 crossmembers, I say.

Would like to stay as low as possible while maximizing clearance between the axles - and I think it can be done with a minimal BL, equal drivetrain lift (I'll draw up the engine mount spacers and crossmembers) and cutting the factory crossmembers off.

I think I have a solution for forward levers with a clocked rear case (napkin math)


I do have a spare frame if I decide to link a solid axle in the future, your suggestion in mind.

 

[Sean K.]

Nope; just removing the issues I see with the truck as-is; save I've gotten sidetracked into dual cases. If I'm going duals, might as well clean up the undercarriage for the cost of 2 crossmembers, I say.

Would like to stay as low as possible while maximizing clearance between the axles - and I think it can be done with a minimal BL, equal drivetrain lift (I'll draw up the engine mount spacers and crossmembers) and cutting the factory crossmembers off.

I think I have a solution for forward levers with a clocked rear case (napkin math)


I do have a spare frame if I decide to link a solid axle in the future, your suggestion in mind.

Gotcha...makes sense. Figured I'd ask just in case.

 

[nevada]

thought it was already 23?

honestly, I have no idea. I haven't followed this closely enough, to know exactly what year/models of t-cases you are using.
I just know on the earlier trucks, most came with a 21 spline input, and putting 4.7's in front will break them.

basically, im saying putting the 4.7 in the front case is a bad idea, but if you are going to do it, make sure you upgrade the input shaft on the rear case. whether they are already 23 spline or not, I have no idea. do they even offer a chromo option? if so, get it.

I think he's saying get the Chromoly rear output shaft upgrade....rather than standard (likely 8620 gear steel).

https://www.marlincrawler.com/trans...tc-hilux/30-spline-chromoly-rear-output-shaft

i had forgotten about those. not exactly what I was suggesting, but I am now.

 

[Roc Doc]

Yes, very doable, especially in a truggy. The benefit of the 4.7 behind the 2.28 is that you don't have to run 5 something axle ratio, so you can run 35's or 33's and STILL have 10.7 low range when you need or want it. But I've run a single case in my L/C for 20 years and I did everything I wanted to do. Well except for that one thing...

IMO, axle gears are all about the street driving. 31`s 4.10, 33's 4.88's and 35's 5.29's. Notice that I'm undergearing with those recommendations. Oversized tires are heavy, especially when you use steel wheels. Porsche has always used the lightest/strongest wheels available as in forged aluminum because rotational/unsprung weight is about 7:1 as important to sprung non-rotational weight as far as acceleration, braking and suspension control are concerned. If you put 35's on your street driving rig, and want to do real rockcrawling, then you're going to have to go to 5.29's but if you don't mind it being a dog on the street and don't do real technical stuff then 4.88's will keep it from running high revs at freeway speeds. When I first got it, I had 35's on it and it could keep up with traffic just fine, but once I went to the 38's it was strictly slow lane.

For me, I was dealing with 120hp or so, and limited street driving so having 5.29's was a must. If I'd had a LS or something with an automatic then taller gearing would be OK, but the combo I had worked well for how I was using the vehicle.

 

[Roc Doc]

Having run just a 4.7 case and duals with 2.28/4.7.....I'd have to say I agree with Roc Doc...for the most part.

If you have a rig with a LOT of sheetmetal, like a T4R, the only real reason for the super deep gearing of the rear 4.7 case is to give more control and less body lurch in really technical sections of trail....like when you're close to bashing the rear window or a door panel in on a tight squeeze rock and you're on the best line to get through the obstacle. That is when having super low gearing is nice.

True dat! If you notice in my pics, everything behind my shoulder is cro-mo, and even then the xtra-cab portion got 'clearanced' over the years. :naughty:

 

[IBallEngineer]

IMO, axle gears are all about the street driving. 31`s 4.10, 33's 4.88's and 35's 5.29's. Notice that I'm undergearing with those recommendations. Oversized tires are heavy, especially when you use steel wheels. Porsche has always used the lightest/strongest wheels available as in forged aluminum because rotational/unsprung weight is about 7:1 as important to sprung non-rotational weight as far as acceleration, braking and suspension control are concerned. If you put 35's on your street driving rig, and want to do real rockcrawling, then you're going to have to go to 5.29's but if you don't mind it being a dog on the street and don't do real technical stuff then 4.88's will keep it from running high revs at freeway speeds. When I first got it, I had 35's on it and it could keep up with traffic just fine, but once I went to the 38's it was strictly slow lane.

For me, I was dealing with 120hp or so, and limited street driving so having 5.29's was a must. If I'd had a LS or something with an automatic then taller gearing would be OK, but the combo I had worked well for how I was using the vehicle.

Right well I wasn't talking about 22R material here. I do have an early LS and an automatic so 4.88's have worked very well for me with 35's, about 120K miles with that set up.
Sadly I've bumped a tree or 27 in my day!

 

[nevada]

Well, without any practical experience in the matter, I do like that 4.7 in the front case gives you 3 significantly different ratios..?

it does the same if its in the rear case. and its a much stronger position to be able to use it.

it is said, to not use just the front case, because it puts too much pressure on the rear case. this is where twin sticks come into play.

however, I use just my first case quite often, I am just very aware of the limitations, and how its used. to avoid breakage.

if the input shaft pops, you aren't going anywhere. dead in the water. and from everything ive read, they typically don't make a sound, or vibration. nothing. you just stop moving..

 

[MandAtaco]

I ran a 4.7 TacoBox for 7.5 years in my 01 Taco. I loved it and wouldn't have it any other way, it gave me options. A lot of time I would just run the crawler in low, and 4 Hi in the rear case. When I needed the ultra low or standard low, I had em.

Lots of guys run this same set up, including behind v8's. Are there some reports of breakage, sure, nothing is bullet proof, but I think enough people have ran this configuration long enough to establish it's credibility as a good option.

I pulled my crawler when I sold the Taco, I just went through it and twin sticked a standard J-shift case that will hopefully be in my 4Runner in the next two months. Waiting till after Christmas to order Triples for it then I'll be ready. Can't wait to get back to this:

<iframe width="560" height="315" src="https://www.youtube.com/embed/L3s7N-jdEg0" frameborder="0" allowfullscreen></iframe>

 

[rkntoy]

it does the same if its in the rear case. and its a much stronger position to be able to use it.

No 4.7 available for the rear case. Unless you switch to a gear-driven lefty case from Inchworm or the Verso from TG.

 

[Sean K.]

I ran a 4.7 TacoBox for 7.5 years in my 01 Taco. I loved it and wouldn't have it any other way, it gave me options. A lot of time I would just run the crawler in low, and 4 Hi in the rear case. When I needed the ultra low or standard low, I had em.

Lots of guys run this same set up, including behind v8's. Are there some reports of breakage, sure, nothing is bullet proof, but I think enough people have ran this configuration long enough to establish it's credibility as a good option.

I pulled my crawler when I sold the Taco, I just went through it and twin sticked a standard J-shift case that will hopefully be in my 4Runner in the next two months. Waiting till after Christmas to order Triples for it then I'll be ready. Can't wait to get back to this:

<iframe width="560" height="315" src="https://www.youtube.com/embed/L3s7N-jdEg0" frameborder="0" allowfullscreen></iframe>

I think the confusion lies in that people are talking the gear driven cases vs. the gear driven crawl box in front of a chain driven one. The latter configuration is proven and works fine. In a pair of gear driven cases, you want the 4.7 in the rear case. ****EDIT*** I was wrong. Apparently, Lowrange Offroad's website now says they don't recommend the 4.7 gears in front of the chain driven case.***

 

[Tyler James Inc]

I think the confusion lies in that people are talking the gear driven cases vs. the gear driven crawl box in front of a chain driven one. The latter configuration is proven and works fine. In a pair of gear driven cases, you want the 4.7 in the rear case.

Hit the nail on the head with that.
I'm not used to guys keeping the chain-drive/DS drop setup, so I don't even think about that.
If it's between putting 4.7's in the front vs rear case, rear is the recommended location.
If I were doing a crawl box, and keeping the chain-driven, I wouldn't hesitate to do 4.7's in the crawl box at all(if I wanted lower than 2.28/2.56).

 

[jkeith.w]

OK, saw this last night also - I'm assuming it could be used to clock the rear while maintaining the front case alignment (for shifter position)?

OK, clarification: I got an email from Nick at Inchworm indicating that the correct part number for the clockable rear adaptor (gear driven front case to chain driven rear case) is IWG-TDCA-23; not on the website, but available. Clockable in 5 degree increments (rear case)

An Inchworm TacoBox adds 8.5 inches, apparently.

 

[rkntoy]

Hit the nail on the head with that.
I'm not used to guys keeping the chain-drive/DS drop setup, so I don't even think about that.
If it's between putting 4.7's in the front vs rear case, rear is the recommended location.
If I were doing a crawl box, and keeping the chain-driven, I wouldn't hesitate to do 4.7's in the crawl box at all(if I wanted lower than 2.28/2.56).

I am going to go the 4.7 route and order up my parts today. After looking at the price of the 23 spline 2.28 input plus the gaskets/bearings I wanted to replace versus the 4.7 kit the difference was only a couple hundred dollars.

 

[jkeith.w]

That's what I was thinking also. What part numbers are you going with, if you don't mind me asking?


Sent from my iPhone using Tapatalk

 

[rkntoy]

That's what I was thinking also. What part numbers are you going with, if you don't mind me asking?

100071-1-KIT Shifter - so I can bend/modify easier than the stock shifter.
105001-1-KIT for the 23 spline input/4.7 gears to go in my reduction box.
107530-1-KIT for 2.7 manual trans.

Then triple shifters from RADesigns.

 

[jkeith.w]

100071-1-KIT Shifter - so I can bend/modify easier than the stock shifter.
105001-1-KIT for the 23 spline input/4.7 gears to go in my reduction box.
107530-1-KIT for 2.7 manual trans.

Then triple shifters from RADesigns.

So I'm correct in assuming that 105001-1-KIT provides everything needed to rebuild the reduction box and convert it to 23-spline 4.7, yes?

Leaving just the A) transmission adapter plate; and B) the rear case adapter plate left to purchase to put a Tacobox together?

(not counting crossmembers, shifters, driveshafts, yada yada)