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Limits of strength on doubled transfer case

Thanks for all the input guys. It sounds like it might not be worth his while long term but to get him back on the trail ASAP he might just throw a 30 spline output in it and start collecting parts for an upgrade. Lead times as we all know are longer then ever so this can buy him some time.

lastly, would it be beneficial to do a 4.7 gear swap while he’s in there? How much weaker are the 4.7 gears? I guess the difference is loading up the rig with 2.28/2.28 vs. the added low end reduction.

It will be interesting to see what he breaks next with a 30 spline output when he’s already running 23 spline inputs
 
Thanks for all the input guys. It sounds like it might not be worth his while long term but to get him back on the trail ASAP he might just throw a 30 spline output in it and start collecting parts for an upgrade. Lead times as we all know are longer then ever so this can buy him some time.

lastly, would it be beneficial to do a 4.7 gear swap while he’s in there? How much weaker are the 4.7 gears? I guess the difference is loading up the rig with 2.28/2.28 vs. the added low end reduction.

It will be interesting to see what he breaks next with a 30 spline output when he’s already running 23 spline inputs

He could always grab a "longfield" out put, not as good as the 30 spline, but should be stronger than stock.

The rear out put is totally separate from the gear reduction unit. So it will have zero effect on the durability of it.

It could be even worse if he has the urge to drop into low low. ~11:1 vs 5.2:1 will break some shit.

Does he like the gearing as is? If so, I'd do the aw4/black box/205. 5.4 from 5.2:frown:
 
Thanks for all the input guys. It sounds like it might not be worth his while long term but to get him back on the trail ASAP he might just throw a 30 spline output in it and start collecting parts for an upgrade. Lead times as we all know are longer then ever so this can buy him some time.

lastly, would it be beneficial to do a 4.7 gear swap while he’s in there? How much weaker are the 4.7 gears? I guess the difference is loading up the rig with 2.28/2.28 vs. the added low end reduction.

It will be interesting to see what he breaks next with a 30 spline output when he’s already running 23 spline inputs


4.7s range from decent to badass, the Sumo gears are a good middle ground for quality Japanese gears at a good price. $550ish IIRC.

If he's killing outputs then that could also be worth upgrading to the RCV Ultimate chromoly output shaft, it's only like $250. I'm adding this into my new dual build as a preventative measure. I'll end up with my drivelines as the weak link which I can deal with on the trail if needed.

Overall, for this thread: Yota cases work well under the right circumstances. Truck, driver, terrain, all add up to how hard the drivetrain gets beat and so many dudes just do the "keep building the truck bigger with no end goal" plan... then get a surprised Pikachu face when their wontons and 42s snap the stock output shaft after a little wheelhop on a climb.

Be honest about your terrain and what tire size that really needs, what engine is needed to turn those tires, and how you will actually drive the rig. Balance out the package from there. There's something to be said for a 4cyl/manual trans/dual case build on Yota axles with 37s.
 
4.7s range from decent to badass, the Sumo gears are a good middle ground for quality Japanese gears at a good price. $550ish IIRC.

If he's killing outputs then that could also be worth upgrading to the RCV Ultimate chromoly output shaft, it's only like $250.

Good call, I forgot about the rcv unit. Not as big as the 30 spline, but should still be a good upgrade.

I'm adding this into my new dual build as a preventative measure. I'll end up with my drivelines as the weak link which I can deal with on the trail if needed.
No you won't.

Toyota driveshafts are much stronger than Toyota cases and axles. I know guys who have all big boy stuff (V8, doubler/205, 1 tons, 42-49s) and still don't break Toyota drivelines. As long as they are good Toyota joints, it's highly unlikely that you will break them over the tcases.

Overall, for this thread: Yota cases work well under the right circumstances. Truck, driver, terrain, all add up to how hard the drivetrain gets beat and so many dudes just do the "keep building the truck bigger with no end goal" plan... then get a surprised Pikachu face when their wontons and 42s snap the stock output shaft after a little wheelhop on a climb.

Be honest about your terrain and what tire size that really needs, what engine is needed to turn those tires, and how you will actually drive the rig. Balance out the package from there. There's something to be said for a 4cyl/manual trans/dual case build on Yota axles with 37s.

I agree with this though. People either have a hug boner for Toyota cases or say they're shit. They actually work really well for what they are, within the limitations. Imo, 4 cyl or some v6s and proper axle gears. They work great with 1 tons as long as they're geared right. 6.xx or 7.xx really help with 40s+. But putting them in the middle of a bigger engine and 1 tons with 5.xx gears and 40s+ is usually a recipe for disaster.
 
Ran dual cases with a 4.0 in the rear case. While your crawling its mint, everything else sucks. The worst of all is the backlash going thru all those shafts, collars and gears.

v8, auto, atlas and 60's won me over, its way more fun.

If i was to do another toy, single case with 4.7's and 5.29's (thats 94 to 1 i believe). It will take a few seconds longer to rev out compared to instantly loosing momentum with a dual case set-up. Crawling was cool for a few years, hauling is more fun.
 
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Good call, I forgot about the rcv unit. Not as big as the 30 spline, but should still be a good upgrade.


No you won't.

Toyota driveshafts are much stronger than Toyota cases and axles. I know guys who have all big boy stuff (V8, doubler/205, 1 tons, 42-49s) and still don't break Toyota drivelines. As long as they are good Toyota joints, it's highly unlikely that you will break them over the tcases.



I agree with this though. People either have a hug boner for Toyota cases or say they're shit. They actually work really well for what they are, within the limitations. Imo, 4 cyl or some v6s and proper axle gears. They work great with 1 tons as long as they're geared right. 6.xx or 7.xx really help with 40s+. But putting them in the middle of a bigger engine and 1 tons with 5.xx gears and 40s+ is usually a recipe for disaster.

It's all a "horses for courses" debate for sure. I like thinking about the tire size needed for terrain, then working my way backwards to think of how the truck will all work together.

The deep gear ratios available for D60s and 9s make me so jealous... My dream buggy build would be on 40s, 7.33 9" diffs, a 4.3 Atlas2, a wide ratio 6sp auto trans, and an LFX V6. High range would be perfect in snow and sand, low range would crawl anything.

I knew that Yota drivelines ranked pretty well in the hierarchy of strength, but it's interesting to hear them hold up under rigs that big. So maybe I'll still kill a case first, or an axle shaft, or a hub... My drivelines will be getting a full once-over with fresh Matsuba/OEM joints when a friend shortens/lengthens them this winter so they'll be good to go.

Ran dual cases with a 4.0 in the rear case. While your crawling its mint, everything else sucks. The worst of all is the backlash going thru all those shafts, collars and gears.

v8, auto, atlas and 60's won me over, its way more fun.

If i was to do another toy, single case with 4.7's and 5.29's (thats 94 to 1 i believe). It will take a few seconds longer to rev out compared to instantly loosing momentum with a dual case set-up. Crawling was cool for a few years, hauling is more fun.

I like a 4.7 single case for some trails, but then you're too low for snow or sand. 95% of the reason I'm going to duals is to have 2.28 and 4.7 low ranges available. With 5.29s and 39s I probably won't use 2.28x4.7 often but it will be nice to have.
 
It's all a "horses for courses" debate for sure. I like thinking about the tire size needed for terrain, then working my way backwards to think of how the truck will all work together.

Makes sense, but I think tire size is more relevant to the vehicle than the terrain, or at least equally so. My little Sami can somewhat keep up with 40-44s since I can weave through shit they have to go over. Being wide and long with small tires is horrible.

The deep gear ratios available for D60s and 9s make me so jealous... My dream buggy build would be on 40s, 7.33 9" diffs, a 4.3 Atlas2, a wide ratio 6sp auto trans, and an LFX V6. High range would be perfect in snow and sand, low range would crawl anything.
Not sure what an lfx V6 is, but ya, I agree. Many people just go for 5.xx because that the normal. I ran 6.17s and 38s on my 4runner and wished I'd had done 7.17s. I never had it on the highway though.

I wish more "lower than 1:1" high cases were available. I li e the 1.65 high in my Sami. 1:1 would be absolutely horrible. The lt230 rover case interests me a lot since it has many high range ratios available from 1:1 to 1.6 iirc. I keep hoping the adapter prices come down. I'd love that case behind a black box.


I knew that Yota drivelines ranked pretty well in the hierarchy of strength, but it's interesting to hear them hold up under rigs that big. So maybe I'll still kill a case first, or an axle shaft, or a hub... My drivelines will be getting a full once-over with fresh Matsuba/OEM joints when a friend shortens/lengthens them this winter so they'll be good to go.

Jesse at high angle rates them equal to 1350. I've seen very few fail, and when they do its usually absolute abuse or a cheap joint.


I like a 4.7 single case for some trails, but then you're too low for snow or sand. 95% of the reason I'm going to duals is to have 2.28 and 4.7 low ranges available. With 5.29s and 39s I probably won't use 2.28x4.7 often but it will be nice to have.

Single ~4:1 or whatever sucks balls for all around wheelers. I do get what he's saying about the lash. It's pretty ridiculous in a dual case Toyota. My buddy used to slam the shit out of his rock sliders on every rock before I told him to just ride the brakes when dropping off stuff.
 
Makes sense, but I think tire size is more relevant to the vehicle than the terrain, or at least equally so. My little Sami can somewhat keep up with 40-44s since I can weave through shit they have to go over. Being wide and long with small tires is horrible.


Not sure what an lfx V6 is, but ya, I agree. Many people just go for 5.xx because that the normal. I ran 6.17s and 38s on my 4runner and wished I'd had done 7.17s. I never had it on the highway though.

I wish more "lower than 1:1" high cases were available. I li e the 1.65 high in my Sami. 1:1 would be absolutely horrible. The lt230 rover case interests me a lot since it has many high range ratios available from 1:1 to 1.6 iirc. I keep hoping the adapter prices come down. I'd love that case behind a black box.




Jesse at high angle rates them equal to 1350. I've seen very few fail, and when they do its usually absolute abuse or a cheap joint.




Single ~4:1 or whatever sucks balls for all around wheelers. I do get what he's saying about the lash. It's pretty ridiculous in a dual case Toyota. My buddy used to slam the shit out of his rock sliders on every rock before I told him to just ride the brakes when dropping off stuff.

An LFX is GM's all aluminum 300+hp 3.6L NA V6. Would be awesome in a sub-4000lb buggy.

The design limitations of transfer cases are an interesting hurdle that nobody has really seemed to get over. Everything is based on old OEM designs of one type or another. Something with a lower high range would be useful to offset axle gear ratios, or allow a functional high range on trail rigs that never have their cases in 1:1.
 
An LFX is GM's all aluminum 300+hp 3.6L NA V6. Would be awesome in a sub-4000lb buggy.

The design limitations of transfer cases are an interesting hurdle that nobody has really seemed to get over. Everything is based on old OEM designs of one type or another. Something with a lower high range would be useful to offset axle gear ratios, or allow a functional high range on trail rigs that never have their cases in 1:1.
Gotcha. The all aluminum 4.3 is pretty awesome as well. It's a "ls1 with 2 cyls chopped off" they are expensive though.

Sami, rover and I think some D18s are the only cases I'm aware of with lower than 1:1 high.

Hero has a 1:1/1.4/3.0 case, but it's $5k. Totally awesome for rock bouncers and ultra 4, but out of most people's budgets. Also, 3:1 alone probably isn't enough for most. You can add the black box i to it, but :laughing: $

As far as the last part of you post, I think that's what the 2.28 crawl box is for. We all used to use it as high, even driving up the road to the trail. :laughing: lots of guys do similar with a 2.7/2.0 cases. One or the other, is pretty much in full time.
 
No you won't.

Toyota driveshafts are much stronger than Toyota cases and axles. I know guys who have all big boy stuff (V8, doubler/205, 1 tons, 42-49s) and still don't break Toyota drivelines. As long as they are good Toyota joints, it's highly unlikely that you will break them over the tcases.
100% this

ive broken so many parts, including chromo parts, that ive lost count. even blew up 4.7 gears, watched a guy snap a 14b shaft, years and year of breaking high quality parts all with toy drive lines and ive only broken a single toy drive line, which was due to axle wrap towing a dead rig up committee on fordyce

toyota drive lines might be the weak link if you put some shitty autozone u joints in it, even then probably not :laughing:
 
We decided the options in the toyota gear market were poor at best, and this thread just confirms it. They are either using a pile of adapters to fit old gearboxes, shafts that were too small or too weak, and some transmissions like the 6 speed got left out completely.
We set out to change things.
We decided to use the VF Planetary gears as the baseline, they're extremely strong, have a decently low range, and already mate to most transmissions after 1990.
A few other bonus features:
No spline connection to rear case
multiple Clocking options
Multiple Rear case options - Want to use an atlas ? Cool, it does that.
We make them in house - no crazy lead times.
ecocrawler1.jpg
image1.png


I'll pop a post up in the Vendor area.
 
No one chimed in after the NWF post. Anyone still following this thread?

The NWF setup gives you dual 2.57 if you run the dual chain drive cases (about 6.6:1 cases)
I’m going to run a 3.4 automatic with one tons 5.38 in the axles on 40” tires. Mostly wheeling the rubicon and fordyce . Is the NWF setup a good gear ratio or will I still “want” a 2.28x4.7 type of setup? (I prefer to wheel slow, it will be a family hauling rig)
 
No one chimed in after the NWF post. Anyone still following this thread?

The NWF setup gives you dual 2.57 if you run the dual chain drive cases (about 6.6:1 cases)
I’m going to run a 3.4 automatic with one tons 5.38 in the axles on 40” tires. Mostly wheeling the rubicon and fordyce . Is the NWF setup a good gear ratio or will I still “want” a 2.28x4.7 type of setup? (I prefer to wheel slow, it will be a family hauling rig)
I am running the exact set up you mentioned, still waiting for my NWF eco box to show up, Ive heard its plenty of reduction for the auto
 
Failgear lefty

20191006_141143.jpg

note the modified idler gear failed due to no heat treatment where it was modified.
this was dualed had 3 mounts (taco trans).
2x4'd it out from buck isl.
so it takes a lot to break a case...:beer:


Just wanted to reply here to say I found the same problem when disassembling my Trail-Gear Verso. The Modified gear is not case hardened after it was machined and the rollers of the bearing were eating into it. I had maybe 10 000 miles on it. It did not fail, but was on the way.
 
Quick question on mounts. I daily drive duals with Chained left side motor mount, marlin crawler front case mount, and a 4x inovations rear case mount. The vibrations aren't terrible but they aren't great either. Could i possibly use a oem-style front case mount along with the 4x rear mount to cut down on in cab vibrations? Has anyone tried this before?
 
Ditch the 4xinnovations mount and replace it with an OEM rubber one. I am running new oem motor mounts, a factory rubber mount on the rear case and recently chained my motor mounts and it's almost 100% vibe free. I used to have a 4xinnovations mount and it was annoying.
 
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Quick question on mounts. I daily drive duals with Chained left side motor mount, marlin crawler front case mount, and a 4x inovations rear case mount. The vibrations aren't terrible but they aren't great either. Could i possibly use a oem-style front case mount along with the 4x rear mount to cut down on in cab vibrations? Has anyone tried this before?
People have been doing this for a long time. Oe in the front and the 4x mount for the rear one.
 
4 oem mounts (2 eng. 2 t case) and bolt or chain.
1 rigid mount anywhere in the setup is gunna transfer the noise...
 
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